Articles By Tonya McKay

CurlChemist

PHOTO TORI LOCKLEAR

By now you've likely encountered the hair tutorial gone wrong that resulted in unassuming YouTuber Tori Locklear losing a full section of hair. The country gasped with her when she realized what high heat had done to her hair, and many of us thought twice before touching a flat iron or curling wand to our strands again.

Temperatures encountered during blow-drying, flat-iron straightening, and hot curling processes can be high enough to cause severe trauma to the hair. Results of this can include cracks in the cuticle layer, bubbles or voids in the cortex, frayed and split ends, chipped and ragged cuticles, faded color, diminished curl and increased frizz, as well as, in Tori's case, broken strands. If avoiding high heat styling methods is not an option, it is important to take precautions to prevent or minimize damage. There are a number of products on the market advertised as heat protectant sprays, lotions, and serums which claim to prevent or repair the detrimental effects of high temperatures on hair. Are these products effective, and if so, how do they work, and which ingredients are responsible for their performance?

Heat & Hair

Flat-irons, curling, irons, and blow driers all impose extreme thermal stresses upon hair strands. With temperatures exceeding the boiling point of water (100°C) and reaching as high as 200°C or more, damage can occur by several different mechanisms.

Dehydration

One heat-induced phenomenon responsible for damage to hair is loss of moisture. Water molecules inside the cortex, both free and bound to keratin proteins, provide critical support to the structure and properties of hair. Evaporation of these molecules due to application of heat can alter the internal protein structure and change the intermolecular interactions that govern the mechanical properties of individual hair strands. This can change curl patterns, cause frizz, and result in hair that is less bouncy and more prone to breakage. The tactile feels of the hair is less pleasant too, having a straw-like texture. This sort of damage is pretty common with routine blow-drying.

Rapid Water Loss

The extremely high temperatures encountered in flat-iron straightening or even straightening using a hair dryer and round brush create intense conditions that can cause water to rapidly boil or “flash” off from sites where it resides within the interior of the hair shaft. This rapid boiling can create voids in the hair structure that can be seen via microscopy and look like strings of bubbles within the strand. These can cause ruptures that burst through the cuticle, leaving gaping spots in the hair, which inevitably lead to split ends and breakage. Cracks can form in the cuticle as well, making the hair vulnerable to further moisture loss and breakage. This type of damage is both severe and completely irreparable.

Protein Damage

Hair strands are complex biomaterials that derive the bulk of their properties from the keratin protein structures in the cuticle and cortex. Thermal degradation from styling tools can occur via softening of the keratin, disruption of the three-dimensional structures due to water loss, and conformational changes in the protein. All of these changes can adversely affect the strength, elasticity, curl, shine, and texture of the hair.

Oxidation of pigment particles

High temperatures can also cause oxidation of pigments found in hair, both naturally occurring ones and artificial hair color. This fading is particularly pronounced in reds, auburns and lighter brunette shades.

MORE: After-Party Hair Repair: Treat That Heat Damage

Products that Protect

Heat protectants are products marketed with the claim that they prevent damage to hair from high temperature styling. Multiple studies have shown that these can be very effective in reducing, but not eliminating thermal trauma to hair. How do they work? The key ingredients in heat protectant products work in a few different ways.

Reduction of moisture loss

Since it is clearly very harmful for hair to lose its precious water molecules, one of the key tasks of a heat protectant is to both maximize and seal in moisture. Humectants such as panthenol, propylene glycol, and phytantriol are used to bind as much water as possible to the hair. Polymers, silicones, and some botanical oils are used to seal the water inside the cortex. They achieve this by coating and encapsulating the strand of hair in a film through which water cannot diffuse. Testing of both control samples and silicone-treated hair strands via thermogravimetric analysis (TGA) showed that silicone treatment significantly improved moisture retention.

Insulation from high temperatures

Silicones (especially amine-functional ones, such as amodimethicone,) some polyquats, and copolymers of acrylates are particularly effective at minimizing the damaging effects of heat styling due to their low thermal conductivity. When evenly distributed across the hair surface into a protective film, these materials act as insulators by reducing the transfer of heat from the styling tool to the hair strand. Data from thermal analysis (DSC- differential scanning calorimetry) confirmed that heat flow was reduced to hair samples treated with these types of materials.

Raw materials suppliers such as Dow Corning, Croda, and GE have also used scanning electron microscopy (SEM) and mechanical testing to evaluate the levels of protection from damage provided by various silicones and heat protectant polymers, and they found that crack formation, cuticle damage, void formation, and loss of strength and elasticity were all reduced when hair was treated with a heat protectant polymer.

What Can We Learn from Tori's Mistake

If you enjoy the results of occasionally flat-iron straightening or blow drying your hair, heat protectant products can make a real difference in how your hair handles those extreme conditions. However, it is important to note that while thermal protection products containing the right mix of humectants and insulating materials can help reduce damage, they cannot completely prevent it. This means that if heat styling is frequently used, cumulative damage will occur. The only way to fix that type of damage is to cut off all the affected length. So, if you prefer to wear your hair long, use heat rarely. Another thing to keep in mind is that some of the polymers and silicones used by these products to encapsulate the hair strand may be difficult to remove and have been known to cause hair to feel sticky or tacky with repeat use.

MORE: I Tried a Dominican Blowout


Where does it come from?

Among the many botanical based ingredients currently popular in hair care routines, amla is perhaps the one that seems the most mysterious, at least from a chemistry point of view.

Amla is derived from the fruit of the Indian gooseberry or Phyllanthus emblica L., a deciduous tree found in both the tropical and subtropical portions of the Indian and Southeastern Asian countries.

The lemon-sized fruit is greenish yellow with attractive vertical striations and has a bitter, sour, and sweet taste. While amla fruit is primarily composed of water, it also contains a variety of sugars, carbohydrates, protein, fiber, minerals, and contains very high amounts of ascorbic acid (vitamin C). For many centuries it has been prized by practitioners of Ayurvedic medicine as well as many other groups for its reportedly amazing medicinal attributes as well as for its beneficial properties for hair and skin.

What does it do?

Advocates who support topical use of amla for hair claim that it is has many uses:

  • cleansing agent
  • deep conditioning treatment
  • dandruff remedy
  • prevents graying of hair
  • darkens hair without use of dyes
  • imparts shine
  • improves hair growth

Too good to be true?

It certainly sounds too good to be true. What exactly is in the amla that is sold for domestic use? Does its composition and chemistry lend any credibility to the many bold claims?

Unless you are fortunate to have access to the fresh fruit, amla is generally available as either a powder or oil. The light brown powder is obtained by drying the entire fruit and grinding it into a powder. The amla oil is actually made by soaking the dried fruit in another oil such as coconut, sesame seed, and sometimes mineral oil. Some of the components of the dried fruit seep into the carrier oil, which is filtered to remove the bits of fruit prior to market. This means that most amla oil products being sold are actually more of a botanical infusion of amla in coconut, sesame, or mineral oil. Although it is possible to extract the fatty acids from the seeds of the amla fruit in the same manner as they are extracted from coconuts, avocados, shea nuts, and argan fruit, it has not been the traditional manner of using this fruit.

ELLAGIC ACID

Chemical make-up of the amla powder

Since the dried powder is made from the whole fruit, it contains all of the nutrients found in the amla, including the fatty acids from the seeds, glucose and the complex carbohydrates, vitamins, phytochemicals, protein, and minerals. The fatty acids found in the seeds are predominantly polyunsaturated ones (~63%), with the remainder being made up of 27% monounsaturated fatty acids and 9-10% medium to long chain saturated fatty acids. These molecules are generally too large and unwieldy to penetrate into the cortex of a hair strand, so they coat the outside of the hair and provide some slip and emollient properties.

Amla & Vitamin C

Amla powder also contains large amounts of vitamin C, which acts as an antioxidant and anti-inflammatory agent, and also may stimulate collagen growth in scalp tissue.

Vitamin C also has antimicrobial properties that can help fight dandruff and other infections of the scalp. The mildly acidifying properties of vitamin C may also enhance the strength and quality of the cuticle layer of the hair and add some shine. Too much vitamin C can be drying to the hair though, so this is probably a good reason to use this powder only occasionally.

Gallic & Ellagic Acid

Two other interesting components of amla powder are phytochemicals gallic acid and ellagic acid. Gallic acid is a phenol molecule that has antiviral, antifungal, and antioxidant properties. It was also used to make ink in Europe and the Mediterranean regions for at least 2,000 years.  While it has not been studied for this purpose, perhaps gallic acid is the agent responsible for the anecdotal reports of gradual darkening of the hair when amla is used over time. Ellagic acid is a polyphenol found in many fruits, especially red ones such as raspberries. It is also documented to have antifungal, antiviral, and antioxidant properties.

These acids could also act as chelating agents to help remove some metals from the hair. Both gallic acid and ellagic acid can also combine with glucose, also present in amla powder, to form polymeric tannic acids.  These may also darken hair over time, as tea has also been used for its tannic acid to darken and dye fabric and hair. It seems doubtful that amla powder can prevent graying of hair or that it can perform any miracles, but it does seem as if it could provide some benefits to hair.

How to use amla powder

  1. Soak the amla powder in water to form a paste, which can then be applied to hair as a mask or used to scrub the scalp. The aroma from this fruit can be fairly unpleasant, so you can add a small amount of an essential oil or botanical extract to give it a more pleasant scent. 
  2. To prevent a mess, use a shower cap to cover your head while the mixture has some time to sit on your scalp and hair. 
  3. Once you have allowed the treatment to sit for a while, gently remove it by rinsing hair under warm, running water and carefully working it out of your hair.  
  4. Follow up with conditioner if your hair feels like it needs more slip.  
  5. Another way to use amla powder is to simply add some to a small amount of conditioner and apply it after it has had a chance to become slightly hydrated. Rinse normally.

Amla Oil

Oils labeled “amla oil” are actually perhaps more accurately called infusions of amla fruit in an oil base.

The carrier oils used are primarily sesame, coconut, almond, or mineral oil and sometimes contain other botanical extracts, such as Ayurvedic herbs, rosemary, and even henna.

It is likely that most of the effects of these products can be attributed to the oil and other actives in the product. Unlike the powdered fruit, these oils contain virtually no vitamin C, as it is not oil soluble. However, there may be some of the phytochemcials, gallic and ellagic acid, present in the oil mixture so it may provide some of the benefits, such as the antioxidant effects, as well as the antifungal and antiviral. Some darkening of the hair may also occur over time with repeat use, although this seems less likely than with the powder.

How to use it

If you wish to try amla in this form, look for one in a plant-based oil to derive the most benefit, and use it as you would coconut or almond oil. You can use it as a scalp treatment, a deep conditioning treatment, or simply add it to your leave-in conditioner, styling product, or directly to your ends.

It is always fun to try new things, or in this case, really old things. Although it is not likely to be a miracle cure for all that ails you and your hair, amla does sound as if it could provide some benefits for your hair and scalp.

Curlies will need to make sure they add plenty of moisturizers and emollients if they use the powder, as it does not have much to offer as far as conditioning on its own. If you already incorporate amla in your regimen and love it or tried it and hated it, we would love to hear about your experience!


Argan oil has been hailed as a cure-all for all your hair and skin care woes. The rave reviews are enough to convince anyone to put some argan oil in your shopping cart - that is, until you see the price. With a 1.7 ounce bottle costing up to $50 and so many other (cheaper) hair oils available on the market, any smart consumer would want to understand what exactly you're investing in.

NaturallyCurly's Curl Chemist, Tonya McKay, breaks down the science behind argan oil.

MORE: Argan Oil Hair Products

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Humectants can greatly help or hurt your hair's moisture levels. Understanding the science behind humectants will help you use them to your advantage.

 

 

Understanding Humectants

Humectants are materials used in products to moisturize dry or damaged hair.  They promote moisture retention by attracting water molecules from the local environment and binding them to specific sites along their structure.  

Adsorption vs Absorption

Absorption is the process whereby a substance passes into the bulk of a material and are dissolved uniformly throughout.   The solution cannot be easily separated into the original two substances.

Adsorption describes the process whereby atoms or molecules are attracted to and adhere to the surface of a material, usually via forces weak enough that they can be easily separated. Some humectants can adsorb several times their weight in water!

In humectants, this happens via hydrogen bonding - a very important phenomenon based upon polarity of specific atoms.

Polarity

Molecules are made of combinations of different atoms.  Sometimes the atoms have significant differences in their 'electronegativity', generating a charge separation where part of the molecule is more positive and the other is more negative.  When this happens, even though the overall charge on the substance is neutral, the molecule has distinct polarity. Imagine a magnet, with its positive end and negative end, and how they can link together end-to-end.

Molecules like water (H2O) have polarity due to the oxygen being much more electronegative than the hydrogen atoms.  The mildly negative oxygen atom is attracted to the mildly positive hydrogen atoms in other water molecules, and they move close to one another and form a bridge, called a hydrogen bond.  Each oxygen can form a hydrogen bond with two hydrogen atoms.  The triangular geometry  of water molecules allows them to stack together into a complex three-dimensional array.

Humectant molecules have polar hydroxyl groups (-OH) that also favor hydrogen bonding.  When applied to hair in a styling or conditioning product, they can attract water from the environment around them and bring it into close contact with the hair.

Humectants and Hair

When humectants bring water into contact with the hair, some can diffuse into the shaft of the hair.  This can add suppleness and softness to slightly dry hair.  It can make hair more bouncy and help it retain curl.  Hair can recoil more easily from mechanical stress and is less likely to break.

Humidity Concerns

In high humidity conditions, humectants may attract too much water to the hair from the wet environment.  This can cause the hair shaft to swell, the cuticle to become ruffled, and hair to lose its shape and become big and frizzy. Porous hair suffers from this problem more so than non-porous hair.  Some humectants may develop a sticky texture in these conditions as well.  This is not pleasant!

In extremely low humidity conditions, humectants may draw water out of the interior of the hair shaft and cause dryness and possible damage or breakage.  Use caution!

Humectants Can Help

  • Make hair feel softer

  • Make hair bouncier

  • Make hair more elastic and less brittle

  • Protect  hair from dry weather and wind

Humectants Can Harm

  • Can create frizzy, sticky hair in high humidity

  • Can dry out hair in low humidity

  • Can cause permanent damage to hair in either extreme condition

Common Humectants

Diols and Triols

Propylene glycol

1,2,6 hexanetriol

Butylene Glycol

Dipropylene glycol

Hexylene Glycol

Glycerin

Triethylene glycol

Erythritol

Capryl glycol

Phytantriol

Hexanediol or -triol beeswax

Humectants of biological origin

Panthenol

Sodium PCA

Hyaluronic acid

Inositol

Glycogen

Sugars and modified sugars

Sorbitol

Polyglyceryl sorbitol

Glucose

Fructose

Xylitol

Hydrolyzed proteins

Elastin, collagen, silk, keratin

Ethers

Isoceteth-x, Isolaureth-x, Laneth-x, Laureth-x, Steareth-x

PEG-x (polyethylene glycol)

Silicone copolyols

Structural formulae for some common humectants: Glycerin, propylene glycol, sorbitol, glucose, and sodium PCA (from left to right, top to bottom)  All images except Sodium PCA courtesy of Wikipedia. Sodium PCA image courtesy of chemblink.com.

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Uses of tea tree oil

A renewed interest in natural substances has increased the availability of tea tree oil as a home remedy, and has also inspired research into its composition and beneficial properties.  While it should never be taken internally due to potential toxicity, it is fantastic for topical treatment at home of

  • dandruff
  • hair growth
  • acne
  • ingrown hair
  • superficial wounds
  • bug bites
  • thrush
  • athlete's foot
  • fever blisters

Tea tree oil also acts as an anti-oxidant. It has been established in several preliminary studies that MRSA (methicillin resistant Staphylococcus aureus) is susceptible to topically-applied tea tree oil. Additionally, it is being studied for its potential use a treatment in some forms of cancer. While those are all rather lofty applications for tea tree oil, it also has benefits for personal care and cosmetic use.

Properties

 

  • antibacterial
  • antifungal
  • antiviral
  • anti-inflammatory
  • antiprotozoal
  • antioxidant

For your scalp

The antibacterial properties of tea tree oil enable it to be very effective in the treatment of acne, with fewer undesirable side effects than benzoyl peroxide.  This is excellent news for those who suffer from this problem on their body, face, or scalp.  It can also be used to treat areas of ingrown hairs or infected follicles caused by shaving.  As an antifungal agent, a shampoo or scalp massage oil that contains tea tree oil helps get rid of dandruff and cradle cap.  Tea tree oil is an effective solvent for sebum and other dirt or oily buildup on the scalp and hair, so it can be used to help provide a clear, clean surface that can absorb moisture and conditioning products more readily.  Additionally, scalp massage with tea tree oil can help stimulate blood flow and reduce inflammation in the follicular cells, which may help enhance hair growth. It is very important to dissolve tea tree oil into another oil medium prior to applying it to the skin and hair though, as it can be very irritating and drying when used in its undiluted form.

For your hair

Based upon its properties, tea tree oil is a viable solution for those with dandruff, itchy scalp, and problems with sebum buildup.  Preparing a solution that is no more than 5% by weight of tea tree oil and massaging it into the scalp and hair may provide excellent benefits.  It can be dissolved into a conditioner, shampoo, or a carrier oil such as olive oil, coconut oil, or jojoba oil.  While there is no definitive proof that it helps stimulate hair growth, it does seem likely to provide the optimal environment for scalp and follicular health, when applied occasionally in the proper concentration.  Remember that it is an effective solvent of oil, which means it can be stripping and drying if used too often or in too strong of a solution.  (Never use it straight!)  Using it as an occasional clarifying agent for hair that is predominantly conditioner washed or that may have buildup of styling product on it is may also provide some benefit and make it easier to rehydrate and condition your hair.  So use sparingly, and to good effect!

Compared to other oils

How does tea tree oil differ from other botanical oils often used for hair and skin care?  Botanical oils, such as coconut oil, shea butter, olive oil, jojoba oil, and almond oil are obtained via the pressing and mechanical extraction of the fats within the fruits from which they are procured.  These fats, called triglycerides, are large molecules comprised of glycerin with three medium chain fatty acids bonded to it.  The hydrophobic nature and physical structure of these oils enable them to behave as excellent lubricants and emollients for hair and skin.  Tea tree oil is an essential oil, which is obtained via steam distillation, fractional distillation, or solvent extraction of the leaves or stems of a plant.  The resultant product is a mixture of volatile organic compounds that have distinctive smells and useful properties, but which do not have the structure to act as lubricants or emollients for hair or skin.

Tea tree oil specifically is made up of dozens of constituents, the majority of which are terpenes, sesquiterpenes, and their corresponding alcohols. Terpenes and sesquiterpenes are a large class of naturally occurring compounds with strong medical relevance, as touched upon briefly in the previous paragraphs.  In addition to their medicinal properties, some (such as limonene and linalool) are used as fragrance additives in cleaning and cosmetic products. The major component in tea tree oil is the monoterpenic alcohol terpinen-4-ol, which comprises anywhere from 30-48% of the oil. Many of the complex benefits of tea tree oil have been attributed to this species.  Some of the components of tea tree oil are toxic or irritants though, which is why it should not be ingested and should be diluted when applied topically. Several cases have been reported where tea tree oil exhibited estrogenic and antiandrogenic properties, so for this reason, frequency of use, concentration of tea tree oil in the product,  and surface of area of coverage may be important factors to keep in mind.

Origin of Tea Tree Oil

Tea tree oil is a distinctively pungent essential oil obtained from the needle-like leaves of the Melaleuca alternifolia, a plant that grows in wet, marshy areas of New South Wales and Queensland in Australia.  It has long been prized by the indigenous Aboriginal people of Australia for its properties as an anti-infective and antifungal agent.  Commercial farming of tea trees (so-named by British explorer,Captain James Cook, circa 1770)  began once the medicinal properties of tea tree oil were studied, documented and published by Australian chemist, Dr. Arthur Penfold in the 1920’s). Subsequently, it became a common household remedy in Australia, and later was included as an indispensable tool in the medical and first aid kits for Australian soldiers during World War II. Demand for tea tree oil declined once antibiotics became widely available in the post-war era, and academic research focus also drifted toward more ‘modern’ topics.


Marketing statements for hair conditioners contain a variety of terms to describe the properties of the products in a manner that is enticing to consumers.  Included in these are familiar words such as: emollient, moisturize, seal, penetrate, repair, and condition.  Ingredient savvy consumers often seek to attribute specific properties, such as “emollient” or “moisturizing” to groups of ingredients in an effort to predictably define which products can meet the unique needs of their hair type. Due to some ambiguity in the usage of many of these terms, a number of questions come to mind when endeavoring to categorize materials in this fashion.

What criteria must be met for a product to be considered a hair conditioner? What are the exact definitions of the various marketing terms when applied to hair care products?  Are any of them interchangeable? What properties make an ingredient moisturizing, emollient, or conditioning? Is it possible for an ingredient to be both moisturizing and emollient? Are there more accurate and precise words that we could be using to describe these properties and ingredients?  Obtaining the answers to these questions can alleviate much of the confusion surrounding additives in hair conditioning products.

What is a hair conditioner?

A hair conditioner is a product which, when applied topically, can improve the overall quality of your hair's surface and bulk properties. Their benefits include increased slip between hair strands (and easier detangling), a smoother cuticle surface, decreased porosity, optimized hydration, decreased electrostatic charge, added body and bounce, and increased strength, suppleness, and elasticity.  Specialized products may also provide protection from thermal and UV damage, as well as improved color retention.   Some of these effects are purely superficial and temporary, requiring frequent reapplication to maintain the properties, while others impart long term benefits by the reduction of damage on a daily basis.

In order to achieve this high level of performance, a conditioner formulation must combine a complicated array of ingredients that both individually and synergistically contribute different properties to the whole package.  Generally, the most basic objectives a conditioner must meet are to provide hydration, lubrication, and occlusion to the hair.  Two common and often confusing terms used to describe the properties of various ingredients in the product are “moisturizer” and “emollient”.  These terms are used in variable ways in marketing statements and in the literature, and are a frequent source of confusion for users.

Moisturizers

The essential qualification for an ingredient to be a moisturizer is that it must improve or maintain hydration levels of hair or skin.  Proper levels of moisture (a delicate balance between too much and too little) help maintain the keratin structure and mechanical integrity of the hair.  Hair with optimal water levels has more body, bounce, and better curl retention.  Curly hair, with its greater porosity and complex protein structure is highly susceptible to water loss, and is thus in particular need of restoration of moisture on a regular basis.

True moisturizing agents are humectants, which are extremely hydrophilic molecules that use hydrogen bonding to attract and hold water molecules from the local environment, making it available to the hair. Some examples of these types of ingredients are glycerin, propylene glycol, panthenol, honey, agave, and aloe vera.  Additionally, a good moisturizing formula will include an occlusive agent, a hydrophobic ingredient which seals moisture into the hair by forming a barrier film on the surface of the hair.  There are some natural oils that have sufficient amounts of hydrophilic bits on their structures that they can act as both occlusive barriers and mild humectants, and some larger molecule sugars that have enough hydrophobic substance to also perform both roles.

Emollients

The term emollient is probably most appropriate for use in skin care applications, but it has been incorporated into the hair care vocabulary, which is often a source of confusion.   An emollient skin care ingredient is one that has good spreadability onto the skin, where it forms an evenly distributed film that softens and smoothes the surface without feeling greasy or tacky. So, if we extrapolate those properties to hair care, we can assert that an emollient for hair should easily form a smooth, even film on the surface of the hair, should soften the hair, and should not yield an unpleasant sticky or greasy texture.

More specifically, emollients for hair are usually hydrophobic oils that form films on the surface of the hair, where they often act as anti-humectants or sealers.  They are lubricants and provide increased slip (decreased drag) between adjacent hair strands, which makes detangling much easier.  They also reduce tangling in general by smoothing and flattening the cuticle surface, which can also add shine and gloss to the hair.  The best ones impart a soft, silky feel to tresses, while lesser ones may weigh it down or make it feel greasy.  Some can penetrate the interior structures of the hair and act as plasticizers, improving elasticity, toughness, and suppleness.

Common emollient ingredients include silicones (dimethicone, amodimethicone, cyclomethicone, etc.), fatty alcohols, fruit and vegetable-derived oils and butters, proteins and hydrolyzed proteins, mineral oil, petrolatum, and polyquaterniums (cationic polymers).  Many of these are entirely hydrophobic, but hydrolyzed proteins and fruit and vegetable oils are typically smaller molecules with fatty acid components that are hydrophilic.  This can enable these to act as both emollients and as mild humectants. Some of these can also penetrate through the cuticle layer into the cortex and significantly improve the mechanical properties of the hair (although for some people, this can weigh the hair down and disrupt curly pattern or swell the hair strand and raise the cuticle, creating frizz).  In extreme humidity, films comprised of these oils can become sticky and dull-looking due to inclusion of water molecules.

Most anti-frizz and anti-humectant serums are comprised of extremely hydrophobic, synthetic emollients such as silicones, emollient esters, and mineral oil or petrolatum.  These typically sit directly on the surface of the hair and act as occlusive agents, barriers which prevent moisture from escaping from the cortex or getting into it from a humid environment.  People who do not use shampoo or use only mild shampoos should be extremely cautious about these types of ingredients and products.

What You Need to Know

Good hair conditioners and hair treatments provide a variety of benefits, including optimizing the hydration and oil levels of your hair and protecting the surface.  Because the terms moisturizer and emollient are actually referring to fairly complex processes and multiple properties, it is not surprising that they are often used incorrectly or interchangeably, which can be confusing.  Marketing materials need to capture your attention quickly, but are not always entirely accurate in their oversimplified jargon.  For this reason, it is considerably more helpful for you as the consumer to determine what your individual hair needs are and to look for ingredients or combinations of ingredients that can meet those needs and to use specific, well-defined terminology to describe those ingredients.

Do you need a humectant to add moisture to your hair?  Do you need a slip agent to reduce tangling (oils, silicones, polyquats, simple quats)?  Do you need a fruit or vegetable oil to decrease porosity and to add softness and elasticity to your hair?  Do you need a water-repellent sealer to prevent frizz in your ultra-humid environment (silicones, mineral oil, serums, anti-humectants)?  Do you need a good conditioning agent to soften, detangle, or to give thermal and UV protection and increased color retention (amodimethicone, polyquats)? Knowing exactly what you want and need for your hair and understanding the terminology and properties of the various categories of ingredients can demystify and simplify the whole process.



A relatively recent addition to the vast portfolio of silicone ingredients available for use in hair care products appears to be gaining popularity amongst formulators, as it is present in a number of new products on the market.  This silicone has an INCI designation (international nomenclature for cosmetic ingredients) that is a mouthful, and it reveals little information regarding its nature to the typical consumer reading a label: propoxytetramethyl piperidinyl dimethicone.  As many people have become more particular about the ingredients they use on their hair, especially silicone derivatives, it is not surprising that this one gives some consumers pause as they wonder what it is and whether it is “okay to use.”  Since there are almost as many different definitions of “okay to use” as there are people who choose to offer their opinion on the matter, gaining an understanding of the chemical structure and properties of the ingredient can help aid you in making your own determination for your hair.

What is it?

Propoxytetramethyl piperidinyl dimethicone (henceforth PTMPD) is a unique, patented cationically-modified silicone described by its makers as a “hindered amino functional silicone fluid.”  It belongs to the same general category as other amine-functionalized silicones, such as amodimethicone and bis-aminopropyl dimethicone.  These silicones have been modified by adding pendant groups suspended from the main silicone chain that contain organo-amine groups (-R-NH2), which become positively charged in water due to electrostatic interactions.  The result is a cationic polymer (positively-charged) that possesses many exceptional beneficial properties for use in hair and skin care applications.

Amine-functionalized silicones are excellent conditioning and protective agents for hair, as they are drawn via electrostatic attraction to its negatively-charged keratin surface.  Once deposited, they spread easily into smooth films that form cross-linked laminate structures that encapsulate and protect both the cuticle and hair shaft.  They are highly valued for their ability to protect hair from thermal damage and to improve color retention.  They also impart a high degree of shine, making hair appear very glossy and healthy.  Like other silicones, they also ease detangling and give hair a soft, silky texture by reducing friction between adjacent strands of hair. Reduction of static electricity and fly-away hair is an additional benefit of these types of silicones.

What makes propoxytetramethyl piperidinyl dimethicone unique?

While propoxytetramethyl piperidinyl dimethicone shares similarities with amodimethicone, it is sometimes found to exceed the performance of amodimethicone in hair care applications.  The reason for this is its chemical structure.   PTMPD is synthesized by the addition of a sterically hindered amine group to the silicone polymer.  Steric hindrance is an organic chemistry term for limited access to a particular portion of a molecule due to the structure of the molecule being sufficiently bulky to physically crowd the site.  Hindered amines (piperidines) are valued for their ability to act as photostabilizers for polymer systems.  They act as radical scavengers, and thus perform well as anti-oxidants.

Is it Water Soluble?

This question always comes up in these discussions because some users prefer to not apply shampoos or soaps to their hair, and they want to use ingredients that can be easily rinsed off with water or with a mild conditioning rinse.  The simple answer to this question for this ingredient is “no”.  PTMPD is not water soluble.

Here is where confusion occurs, and it is worthwhile to attempt to provide some clarity.   The preparation of hair care products is a complex science involving the mixing of hydrophilic and hydrophobic substances together to create a product that consistently performs in the manner expected and retains its beneficial properties for a predictable period of time.  A fundamental scientific theory taught to us all at an early age is that oil and water do not mix. Fortunately, this inherent limitation can be overcome via the use of emulsifiers and stabilizers and mixing the ingredients in just the right order. It is unacceptable for the oils to separate from the aqueous phase, or for the preservatives to settle to the bottom, or for the opacifiers to crystallize and precipitate from the solution. Additionally, preparing the mixtures and emulsions should require the least amount of time and heat energy possible in order to maximize profit for the manufacturer.  This is not a trivial assignment, and the application of much scientific theory goes into the process.

Silicones bring added difficulty to the table for formulators and product manufacturers, due to their insolubility in both water and in most organic oils.  This requires them to be pre-emulsified by mixing them with multiple surfactants (usually a nonionic and cationic one) in water to form an aqueous emulsion or micro-emulsion.  The droplets of silicone form an aggregate with the nonionic and cationic surfactants and are suspended inside micelles (tiny spheres) that are dispersed in the aqueous phase of the solution.  The outer shell of these micelles is the hydrophilic portion of the surfactants, which renders these particles soluble in water.  This emulsion can then be added to an aqueous shampoo or conditioning product fairly easily.  To save time and resources at the final production site, oftentimes the raw materials manufacturer will simply provide the materials as a pre-made micro-emulsion.

So, it is important to remember that the PTMPD (and other amine-functionalized silicones) is not water soluble itself, but is grouped with other materials to make it be so for the sake of the product manufacturing process as well as for the  stability of the final product.  Once the product is applied to the hair, the positively-charged silicone and the positively-charged cationic surfactant both separately adhere to various negative sites on the surface of the hair, forming a protective, emollient film, and the nonionic surfactants are washed away.  The micelle cluster no longer exists, and the polymer is completely insoluble in water.

Once applied to the hair, propoxytetramethyl piperidinyl dimethicone is highly substantive due to the ionic bonds formed between itself and the negatively-charged surface of the cuticle. A powerful anionic (negatively-charged) surfactant is necessary to remove this type of polymer form the hair.  Even then, it may be highly resistant to removal. This property is considered to be favorable by most formulators, as it means that the benefits imparted by the ingredient will persist over multiple washings.  It does not build up on itself, and it does not attract organic oils to itself, so those will also not build up on top of it.

However, some users have expressed their belief that this persistent film caused their hair to become dehydrated, frizzy, or unpleasant in texture.  While this experience is not universal, this anecdotal evidence certainly cannot be dismissed or discounted.  One might also speculate whether the anti-oxidant properties diminish over time, or whether the optical properties of the film change and result in a duller appearance to the hair.


In closing, it is clear that amine-functionalized silicones provide many advantageous properties when used in hair care products. Among these are high gloss, lightweight conditioning, fewer tangles, and protection from thermal damage.  This particular polymer, PTMPD, provides even greater benefits in terms of color retention, sun protection, and intensive, targeted conditioning properties for damaged hair.  However, if one ascribes to shampoo-free methods of hair maintenance, this silicone might be too difficult to remove from your hair and could create unpleasant side effects over time.  If you have been displeased with the results of amodimethicone on your hair, this might be another silicone to avoid as well.  However, for most people, products containing PTMPD can be a really nice addition to the hair beautification and protection arsenal.


References

http://www.faqs.org/patents/app/20120178324 (HA info patent)

Urrutia, Adriana, Silicone: The Basis of a Perfect Formulation for Hair Care,

Dow Corning de Mexico S.A. de C.V.


What is Magnesium sulfate?

Magnesium sulfate is an ingredient often touted as a natural curl booster or curl activator for hair. It is typically used in leave-in conditioners and curl enhancers, both commercially available and homemade, and it is applied via a spray-on delivery method.

Many people have noted that their hair often responds remarkably well to the initial application, but further uses yield dry tresses that behave in an unruly fashion.  Several explanations have been put forth for this phenomenon, but there still remains some confusion as to why it happens.

By delving into the protein structure of hair and curls, and how magnesium sulfate interacts with these, we can gain clear understanding of the mechanism by which magnesium sulfate enhances curl pattern and retention, and also why the effects seem short-lived and eventually become unpleasant.

Hair Keratin Protein

Other types of crosslinking also occur between the polypeptide chains, and they also contribute to the structure of the hair. These two additional types of crosslinking are achieved via hydrogen bonding and formation of salt bonds and are sometimes referred to as secondary bonds. However, both of these types are physical crosslinks, rather than chemical ones (imagine it as two strands taped together or two magnets attracted to one another versus two strands sewn together or melted and re-formed into one object), and are susceptible to disruption via mechanical forces (touching or brushing the hair, wind) or the presence of water (swimming, washing, humidity, rain).Proteins are polymeric molecules (also called polypeptides) made up of many repeat units of various amino acids. The sequence, type, and order of the amino acids vary greatly depending upon the function of the specific protein. Hair is comprised of keratin protein, a polypeptide particularly differentiated from other proteins for its large proportion of cysteine, a sulfur-containing amino acid.  These polypeptide strands are crosslinked (bound together into a three-dimensional network) via formation of covalent bonds between adjacent cysteine residues. This linkage is a chemical crosslink referred to as the disulfide bond, and is the source of the strength and physical configuration of the hair. As the degree of disulfide crosslinking in a strand increases, so does the amount of curl in the hair.

Perms enhance curls by breaking the disulfide bonds via chemical means, curling the hair tightly to physically restructure it, and then re-forming the disulfide bonds at a higher percentage. Several researchers have found that hair is stronger and curl retention is increased when magnesium sulfate is incorporated into the rinsing and neutralizing agent used to re-form the disulfide bonds. They also noted that its use enhanced the curl pattern and imparted a greater stability to high humidity.

Magnesium sulfate

Magnesium sulfate, also known as Epsom salts, is an inorganic compound that exists as a hydrated material, magnesium sulfate septahydrate (MgSO4• 7H2O). This salt is extremely hydrophilic and thus easily dissolved into an aqueous solution that can be spritzed onto the hair. It attracts and binds water molecules from its surroundings to itself.  When MgSO4 is applied topically to hair it does not affect the covalent disulfide bonds, but it does impact the physical crosslinks formed by hydrogen bonds. By increasing the number of hydrogen bonds, the Epsom salt tightens the curl pattern of the hair.

The mechanism by which magnesium sulfate achieves this curl activation consists of two steps.

  • First, the magnesium neutralizes the excess negative charges on the surface of the keratin and brings it to its ideal pH (also known as its isoelectric point).
  • Secondly, a dehydration mechanism via a salt-protein interaction increases the quantity of hydrogen bonds (physical crosslinks), which makes the hair curlier.  This second part is what is critical to understand.

Hair keratin protein incorporates water into its structure. This moisture gives it softness and pliability and is why we strive to maintain properly hydrated hair. However, in a highly hydrated environment, the formation of hydrogen bonds between adjacent cysteine amino acids is minimal. But, in the presence of the highly hygroscopic salt, MgSO4, the keratin protein becomes dehydrated. This dehydrated environment is what permits the formation of additional hydrogen bonds and the curl activating properties of magnesium sulfate. Thus, the very quality that permits magnesium sulfate to boost curl formation is also the one that generates the poor results in subsequent uses.

Magnesium sulfate also forms fairly large crystals, and these structures can roughen the surface of hair, yielding an unpleasant texture and tactile experience for some. They may increase tangling as well, if adjacent hair strands get caught on them. For this reason, it is advisable to use a good lubricative leave-in conditioner along with a magnesium sulfate. (Dare I say it? A silicone might work nicely and not interfere with the curl forming effects of the MgSO4).

Magnesium Oil

Some products are beginning to advertise that they use magnesium oil, rather than magnesium sulfate.  These are typically a supersaturated aqueous solution of magnesium chloride (MgCl2). The chlorine molecule changes the properties of the salt, rendering it slightly less hydroscopic. For this reason, it may not boost curl as significantly, but also will not dehydrate and potentially damage the hair as much. It seems a reasonable type of product with which to experiment.

Take-home message:

Magnesium sulfate can indeed be a useful curl activator or curl booster and has a place in the arsenal of every curly girl (or guy).  However, the mechanism by which it achieves this effect leaves hair, especially fragile curly hair, very vulnerable to damage due to dehydration.  This effect can be minimized by using magnesium sulfate infrequently as an emergency agent, or using it in conjunction with products that deeply moisturize and protect the hair.  Definitely condition very well after every use!


hyaluronic acid

Biologically sourced substances continue to gain popularity as ingredients in skin and hair care products.  This trend is in response to consumer and government demands for more natural and sustainable products, and is strongly driven by advances in fundamental understanding of biomaterials.  One such material is hyaluronic acid, a biopolymer highly valued in cosmetics for its hydrating and nourishing properties.  Its value as a beneficial topical skin cream agent is fairly well accepted, but does it improve the performance of hair care products?  What results can the consumer expect from shampoos, conditioners, or styling products that contain hyaluronic acid, and are there any potential drawbacks for curly haired users?  The answers can be found in the relatively simple structure, yet surprisingly complex physical and biochemistry of the molecule.

What is Hyaluronic Acid?

Its name is relatively simple and deceptive, conjuring images of various small molecule acids, such as ascorbic, acetic and citric acid.  However, hyaluronic acid is a surprisingly complex biopolymer. HA is a polysaccharide categorized as a glycosaminoglycan (GAG), and is a very high molecular weight (107 Da) , non-sulfated, anionic (negatively-charged) polymer.  Its physical structure is linear and is comprised of alternating units of D-glucoronic acid and D-N-acetyl glucosamine.  This polymer is found in virtually all vertebrate tissues, and is particularly active in the extracellular matrix (ECM) in connective tissue.

The ECM fills the space between cells and is a complex array of proteins and polysaccharides that self-assemble to form a network that provides support, structure, and mechanical integrity to the tissue.  Depending upon the function of the tissue, the type and structure of polymeric and small molecule components varies, which facilitates the development of the specific mechanical properties necessary for the particular tissue type (i.e. bone versus skin, etc.).

As a component of the ECM, hyaluronic acid performs many functions, including acting as a tissue scaffold to which sulfated proteoglycans can attach, creating a complex three-dimensional hydroscopic network that forms a viscous gel.  Its highly hydrophilic structure causes it to attract and bind water to itself, which enables it to hydrate and provide turgor (rigidity) to tissue. This enables the matrix to resist compression, which allows it to provide cushion to joints, organs, and the dermal layer. It is also thought to provide hydrated pathways that promote and regulate cellular movement and migration.  Additionally, hyaluronic acid interacts with cell membranes receptors (specifically CD44) to trigger intercellular signaling pathways that direct and control cellular processes involved in growth, healing, and also some pathological processes such as inflammation and tumor development and growth. Hyaluronic acid also aids in protection of tissue and processes by scavenging free radicals and is thus an effective antioxidant.

woman applying lotion to skin

Cosmetic Applications

Clearly, hyaluronic acid is critical for healthy and effective function of living vertebrate tissue. As much as 50% of the hyaluronic acid found in the human body resides in the basal layer of the epidermis, where it is critical to the structural and mechanical integrity of the skin and keeps skin hydrated, plump, and aids in tissue repair.  For this reason, it became a clear candidate for incorporation into topically applied skin creams, such as lotions and wrinkle reducers.

  • HA forms a film on the surface of the skin and hydrates it through its humectant properties.  
  • It also forms a gel that can fill and plump wrinkled skin and provide a temporary illusion of younger skin.   
  • It is thought to be useful for the scalp as well, where it may provide a hydrated network structure which promotes scalp health and helps optimize hair growth.

The naturally-occurring version of hyaluronic acid is extremely large, with a molecular weight in the millions or tens of millions.  Oftentimes, a lower molecular weight version of the polymer is used in cosmetics, particularly in hair care products.  This permits the polymer to be deposited onto the surface of the hair, where it can provide smoothing and hydrating benefits.  Some product manufacturers claim that their smaller molecule HA can penetrate the hair shaft and attract water to itself from the environment, thereby imparting moisturization and suppleness to the hair strands.

Unfortunately, hyaluronic acid is not highly substantive to keratin protein surfaces and has a time-limited impact, which requires frequent re-application.  Several manufacturers have designed materials that enhance the substantivity and conditioning/moisturizing benefits of hyaluronic acid.  One approach has been to simply modify the polymer by synthesizing a cationic derivative (hydroxypropyltrimonium hyaluronate), which adsorbs and remains on the hair via electrostatic interaction between the positive sites on the polymer and negative sites on the hair strand.  This ingredient is claimed to “plump the hair shaft”, which may be true due to the large quantity of water that HA can bind to itself which could cause the hair to swell.  Depending upon the local climate and the hair type of the user, this may not in fact be a desirable effect as it can result in some frizz in more porous hair, but people with finer or less porous hair might enjoy the boost.

Amerchol, a subsidiary of Dow Chemical, has developed a second approach to overcoming the lack of substantivity of HA to proteins surfaces. They created a dual polymer association complex, resulting in what they refer to as a “synergistic polymer composite,” which exceeds the properties of either polymer on an individual basis.#  Polyquaternium-24 (PQ-24), a cationic polymer derived from hydroxyethyl cellulose (HEC) was mixed with HA to form a polymer complex that was highly substantive to hair and skin.  It was found to produce excellent hydration and to be emollient and smoothing to the surface of both skin and hair.  This reduces tangling and makes hair softer.   An additional complex of polyquaternium-10 and HA was also produced, and demonstrated similar favorable results.

(These materials are denoted on labels via INCI names of: polyquaternium-24 and hyaluronic acid or polyquaternium-10 and hyaluronic acid.  The “and” denotes the presence of this polymeric association complex).

Analysis with techniques such as X-ray photoelectron spectroscopy enabled the scientists to confirm that the polymer complex formed a smooth film on the surface of the hair.  They also were able to determine that the film that forms is not a monomolecular layer (one polymer molecule deep), but rather, is a three-dimensional network matrix that plumps hair and feels fabulous on skin.

The thing that may be of concern to curly-haired users of products containing these polymer complexes of HA and PQ, is that the researchers at Amerchol found that in these mixtures, contact time with the HA was maximized, meaning it was so highly substantive that it actually resisted removal for up to three consecutive washes.#  This can be considered highly beneficial for skin, where you might wash your hands repeatedly, and a highly substantive cream can provide protection and hydration through multiple washes prior to requiring re-application.  However, in hair, one must be curious whether this increased substantivity could result in any undesirable effects, such as buildup, dehydration, or frizz.  Theoretically, this would not be a problem due to the highly ionic character of both the PQ and the HA polymers, but data proving this would be reassuring.

Sourcing

Hyaluronic acid is present in tissues of vertebrate animals.  For this reason, HA has most often been obtained from animal sources.  Many consumers find this unpalatable, so scientists have developed synthesis techniques to make plant-sourced HA in the lab, using a bio-fermentation mechanism.

In closing, hyaluronic acid is a remarkable molecule critical for many biological processes.  As a hair or skin care ingredient, it imparts amazing suppleness and smoothness, and in hair care products, HA can be an excellent conditioning agent, antioxidant, and humectant.  As with other humectants, perhaps even more so due to its extreme water-attracting capabilities, HA may result in problems associated with humidity – frizz and unpleasant texture. As a standalone ingredient, it is not highly substantive to hair and skin proteins, and thus can be easily rinsed off with water or using a mild shampoo or conditioning wash.  Modified versions of HA that include quats may be extremely substantive to hair and resist removal via most methods.  However, it is not clear whether this has any negative effects on the softness, curl, shine, or body of the hair.


References

Nusgens BV., Hyaluronic acid and extracellular matrix: a primitive molecule? Ann Dermatol Venereol. 2010 Apr; 137 Suppl 1:S3-8.

Oscar Blandi, Hair Lift Instant Thickening and Strengthening Serum

Amerchol Corporation, 136 Talmadge Road, Edison, NJ 08818-4051 USA, BIOCARE Polymer Complexes For improved hydration and moisturizing in personal care products

Pavlichko JP, Goddard ED, Band PA, Leschiner A. Enhanced substantivity of hyaluronic acid on keratin substrates via polymer complexation., Int J Cosmet Sci. 1994 Dec; 16(6):227-34.



Curly haired woman on beach

Most of us have been recipients of much indoctrination regarding the benefits of antioxidants, both for our health and our appearance.  Eat your multi-colored vegetables, drink your freshly-obtained green juice, take your vitamins, and slather on expensive skin creams loaded with these nebulous molecules, and you will be fit, appear young, beautiful, active and healthy, right? With claims like these, it seemed inevitable that hair care products showcasing these materials would make their debut on the shelves of hair salons, health food stores, and drug stores, and of course, this is the case, especially in the natural market sector.

But are these ingredients truly beneficial when used in topically applied hair care products, or are they simply a clever marketing strategy with minimal effects?  A consumer armed with knowledge of what oxidative damage is, how it occurs, and what can be used to protect against it has the advantage when evaluating product claims and making purchases.

What is oxidative damage?

Oxidation is the process whereby a molecule loses an electron and is cleaved into its substituent atoms or groups.  Some of these species are left having an unpaired electron in their outer shell, which leaves them in a highly unstable and reactive state, as they are driven to complete their outer shells via pairing all electrons.  These are called free radicals or reactive oxygen species (ROS).

In order to complete its outer shell of electrons, the free radical will attack adjacent molecules and abstract an electron from them, generating a new radical which is also unstable and seeks to “steal” an electron from its neighbors.  This initiates a chain reaction, which is the basis of many polymerization reactions, but which can also be very destructive to living cells and systems.  These free radicals can attack cell lipid layers, DNA, proteins, and many other essential structures, disrupting key biological processes and resulting in aging, decreased function, and pathological processes such as cancer.

Hair is not comprised of living cells, but its keratin-based structures are still susceptible to oxidative damage from a wide variety of sources.  This damage leads to split ends, broken hairs, rough cuticles, frizz, tangling, lack of luster, diminished curl retention, and loss of color (natural or artificial). Identification of the many sources of free radical exposure can help a curly to reduce their overall risk of accumulating this type of structural degradation.

Exposure to ultraviolet radiation is one frequent route for oxidative damage, where the sun’s rays penetrate the hair shaft and deplete the natural melanin resident in the cortex and also alter the protein structures of both the cuticle and cortex.  Chemical processes, particularly bleaching and permanent dyeing are culprits in the depletion of natural melanin and creating substantial oxidative damage.  Additionally, relaxers, perms, keratin treatments, and heat styling contribute to formation of free radicals, which attack both the lipids and the proteins in the cuticle structures.  Exposure to ozone, pollutants, tobacco smoke, substances in our water, as well as radiation all add to the continual exposure to free radicals and their damaging processes. Damage is pervasive and cumulative, and damaged hair becomes more porous and even more vulnerable to oxidative damage. For this reason, prevention and minimization are critical to preserve the health and beauty of hair.

Common Antioxidants

 

  • Vitamin E (α-Tocopherol)
  • Beta Carotene
  • Vitamin C
  • Vitamin A 
  • Phytochemicals
  • Plant extracts (green tea, grape seed extract, lemongrass, oolong, kiwi)
  • Selenium
  • Trace minerals

How Do Antioxidants Work?

We know from advertisements and reports in the media, as well as from more academic sources, that antioxidants are the key to dealing with this constant attack from free radicals, but what exactly is their role in the process?  Antioxidants mitigate and prevent damage to cells and structures from free radical and reactive oxygen species by putting the brakes on the chain reaction that destroys everything around it.  The mechanism by which they achieve this varies, depending upon the antioxidant, but generally it is accomplished via an electron or hydrogen donor process.  These molecules are called free radical scavengers.

One common antioxidant is Vitamin E (α-Tocopherol), which donates an electron to an unstable free radical, rendering it stable, but becoming oxidized itself.  However, rather than becoming a participant in the free radical chain reaction, the oxidized version of α-tocopherol is then either excreted or regenerated via reduction (hydrogen donation) by Vitamin C (ascorbic acid).

Vitamins A, E and C

Effects for Hair?

While it is well-established that antioxidants are highly efficacious both when taken internally and applied to the skin via cosmetic preparations, it is natural to speculate whether or not they have equal value when applied topically to the hair, which is not a living cellular structure.  Fortunately, the evidence indicates that there is plenty of benefit to be derived from the inclusion of antioxidants as components in formulations for rinse-off products, leave-in conditioners, and styling agents.

Vitamins and vitamin precursors such as Vitamin E, Vitamin C, and beta carotene have been found to have protective effects against environmental free radical assaults on hair. In a manner similar to sunscreens, these materials form a sort of interactive molecular shield against the elements, at least temporarily. By preventing the destruction of melanin and synthetic dye molecules in residence in the cortex of the hair strand, free radical scavengers can be quite useful in improving color retention and maintaining the health and integrity of hair.  Experiments have also generated data that demonstrates the efficacy of topically applied antioxidants in mitigation of damage from both coloring and heat processes.

Oil soluble vitamins such as α-tocopherols and beta-carotene and vitamin A and lipophilic plant extracts are the more common antioxidants found in hair care preparations.  The reason for this is that due to exposure to air many reactive oxygen species are generated in the aqueous phase in the bottle of product, where water soluble vitamins such as ascorbic acid (Vitamin C) would be present.  The ascorbic acid is then rapidly depleted via oxidation reactions with the free radicals, and is thus comparatively short-lived in its availability to perform its preferred function on the hair.

One method chemists have used to circumvent this problem has been esterification of the ascorbic acid, which converts it to a lipophilic substance and increases its duration of efficacy.  However, this additive is more expensive and diminishes its potential to scavenge radicals in the aqueous phase when hair is wet, which is when it is needed.

Furthermore, it is the assertion of research chemists at Mibelle Biochemistry in Switzerland that the inclusion of both water soluble and oil soluble antioxidants provides the best range of protection. For this reason they have been developing methods to include more stable water soluble antioxidants and blends (such as grape seed extracts + α-tocopherols) that provide highly effective protection of the cuticle and cortex, even in rinse-off products.  Another research team has taken the approach of encapsulating ascorbic acid in micelles comprised of a nonionic surfactant (Polysorbate 80) and mixed tocopherols.  This nanoemulsion is supplied as a gel-like aqueous solution that is easily mixed into a formula.  The Vitamin C remains protected and active for a greater duration due to being in the interior of the micelle.

Conclusion

Our hair is being constantly bombarded by reactive species of molecules that slowly tear apart the very complicated biopolymeric structure of each strand.  Without adequate protection, especially for longer hair, the damage grows continually worse until it becomes very evident. Color fades quickly.  The surface becomes rough and porous.  Tangles, breakage, and frizz become the norm.  Curly hair, which has a rougher surface than straight hair is even more susceptible to this type of degradation.  Fortunately, it has been found that some botanical oils, vitamin E, vitamin C, and beta carotene do indeed provide some protection against these environmental sources of free radicals.  They also provide emollient properties and other benefits to the hair, and thus seem to be good additions to products for curly hair.  They are not substitutes for wearing a hat and treating your hair kindly though, so protect those tresses!


[1] F. Zülli, E. Belser, M. Neuenschwander & R. Muggli, Antioxidants from Grape Seeds Protect Hair Against Reactive Oxygen Species, Mibelle AG, Switzerland,   http://www.mibellebiochemistry.com/publications/gsp-tantioxidants.php

 

[1] Behnam, Dariush (Rossdorf, DE), Aqueous solution of ascorbic acid and method for producing same, United States Patent 6774247, 2004, AquaNova German Solubilisate Technology (AGT) GmbH (Darmstadt, DE) http://www.freepatentsonline.com/6774247.html



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