brazilian keratin treatment

What is the truth about Brazilian Keratin Treatments?

Brazilian keratin treatments are a really popular process right now, and are being discussed on the internet, television, and in popular beauty magazines. I must confess that my initial reaction was a negative one, as I found myself thinking "Oh, fantastic; they have found yet another way to reinforce the image of curly hair as the ugly stepchild of cosmetology." However, once I read some of the personal experiences of fellow curlies, such as that of Michelle Breyer, co-founder of, I became intrigued and began seeking information about this procedure — particularly information on a scientific and mechanistic level.

What I found was a baffling morass of spectacularly attractive claims, a lot of proprietary ingredients, a whole lot of nothing regarding the actual chemical mechanism by which these processes work, and a lot of controversy regarding the use of potentially harmful ingredients and very high temperatures. A variety of results have been reported, ranging from exceedingly satisfied and ecstatic customers, to those who were mildly disappointed, to a number of consumers reporting dramatic and significant hair loss.

I feel a little like Dorothy setting out on the road to find the Wizard of Oz. There seems to be a lot of smoke and mirrors in use, and I really, really want to know who (or what) is behind the curtain. This article will be my first attempt to penetrate the veil of mystery surrounding these hair treatments. I suspect that some follow-up research will be necessary, and at least one more article on this topic will be in my near future.

Amazing Claims

The claims made by the makers of these products are quite attractive. Keratin smoothing treatments are said to be especially beneficial to those with curly and/or frizzy hair. The treatment is reported to be able to relax curls substantially (in some cases straightening hair entirely), reduce frizz by up to 95%, impart shine, provide body, and render previously difficult hair into locks that are easily manageable. Imagine being able to run a comb or brush through your hair in the morning without wetting and conditioning it first! People with curly or wavy hair who like to blow it out straight usually have to spend 45 minutes to an hour achieving the look they desire. But once they have had this treatment, it is often possible with very little time and effort.

The results described by some of the people who have tried it sound amazing and extremely enticing (see Michelle's Brazilian Blowout Blog to follow the journey of a beloved fellow curly who has had remarkable success with this treatment).

Here are some examples of some benefits touted by a few of the manufacturers:

Coppola Keratin Smoothing Complex

  • Rebuilds, restores, rejuvenates
  • Keratin is bonded into the cuticle by the heat of the flat iron to relax the hair's sub-cuticle layer
  • A life-changing experience
  • Eliminates up to 95% of frizz and curl

Brazilian Blowout

  • Minimizes frizz, loosens curl
  • Conditions hair and seals cuticle
  • Makes hair appear straight and healthy
  • Utilizes a "super nutrient complex"
  • Contains a proprietary polymer system
  • Repairs existing damage
  • Rounds the follicle
  • Reduces curl and frizz by 90% or more

Sunliss Keratin Hair-Straightening Treatment

  • Straightens and revitalises your hair with its cocoa-based formula
  • Rich in theobromine, a substance recognized for its powerful hydrating qualities.
  • Delivers high concentrations of fatty acids to the core of the follicle, providing unprecedented smoothness.
  • Recommended for straightening and re-aligning dry, fragile and frizzy hair.
  • The active ingredients in our keratin-based straightening products are unique in their ability to perform a capillary re-alignment, thanks to the carefully formulated composition of keratin, oats and cocoa.

Marketers also claim that Brazilian keratin straightening treatments work better on hair that has been chemically processed by coloring, perming, or straightening. The reason for this is that these types of procedures leave permanent gaps and flaws in the cuticle layer. These flaws allow hydrolyzed keratin (amino acids and polypeptides) to penetrate more easily into the hair shaft and also act as attachment sites for keratin on the surface of the cuticle.

Due to the porous nature of processed hair, retention of the added keratin and its building blocks is also enhanced, so the effect from the treatment can last longer. An additional consideration is that hair that is already damaged will naturally benefit more from topical treatments that improve shine, suppleness, and softness than hair that is already healthy, shiny, and straight. However, it also seems intuitive that hair that is damaged already may be more susceptible to additional damage caused by the use of extreme heat to reshape it.

What's in there?

Although it seems nearly impossible to get accurate and complete ingredient lists for these products, most of them do seem to contain similar general types of ingredients.

  • Keratin protein, obtained from sheep's wool or other sources, usually hydrolyzed into lower molecular weight polypeptides as well as amino acids
  • An aldehyde or aldehyde precursor of some sort (formaldehyde, vanillin, bioformyl, glyoxal biformal)—forms a reversible bond with cysteine (prominent amino acid in hair keratin)
  • Conditioners — fatty alcohols, cationic polymers (such as polyquaternium-7, amodimethicone), silicones (amodimethicone, dimethicone, dimethiconol, cyclic silicones), lanolin
  • Polymers and biopolymers (such as collagen)
  • Preservatives, fragrances
  • Metallic nanoparticles (gold, copper) — unique to QOD Cosmetic products, the metal nanoparticles catalyze the reaction in a manner similar to the aldehydes (possibly)

How does it work?

When a client first comes into the salon to receive a keratin smoothing treatment, the technician or assistant will wash her hair to make sure the surface is free of contaminants or chemicals from styling products. Then a liquid solution will be applied to the hair. This solution contains keratin, as well as other ingredients, such as conditioning agents, aldehydes or other catalysts, preservatives, etc.. The hair is then blown dry and straightened using a flat iron on very high heat (450°F is the recommended temperature).

Most of the formulas contain a formaldehyde solution called formalin. (MSDS for Formalin (37% Formaldehyde solution, with methanol)) Some of the current products use other aldehyde molecules, while yet others claim to be "aldehyde-free." I could find no descriptions in the scientific literature of the mechanism by which this product works. I had to dig through biochemical and biomedical literature to get some clues, and think I arrived at a possible mechanism. I am wading in with my chemistry high boots on, and this is more of an educated guess than anything.

Aldehydes readily react with amino acids, especially cysteine, a sulfur-containing amino acid prevalent in both human hair keratin as well as in keratin derived from other species. This is known in organic chemistry as a Schiff-Base reaction. This technique has been used in the preparation of biological samples for electron microscopy study. Formaldehyde and other aldehydes in the human body can crosslink proteins and DNA and through a complicated series of reactions can transform protein structures into what is known as advanced glycation products (AGE). These AGE products are undesirable and are responsible for inflammation and other diseases in the body, so it is interesting that someone thought to exploit this reaction in a way that would be advantageous and would hopefully have no deleterious effects.

When these keratin treatment solutions are applied to hair, the aldehydes react with cysteine found in both the keratin solution and also with the hair. This creates crosslinks between hair keratin and product keratin and holds them together in a semi-permanent fashion. The bonds do not last forever though, and are gradually broken and the keratin is washed away in the shower, which allows the hair to return to its pre-treatment state.

The smaller polypeptides and amino acids of the hydrolyzed keratin penetrate the cuticle and help to plump the hair and fill in gaps. The larger-molecular-weight portions form a film on the surface of the hair and are held there by the crosslinks. The high-temperature flat-ironing process straightens the hair and locks in the new straighter conformation as well as seals the cuticle and the keratin film on the surface.

The distributors of products that make the claim to be aldehyde-free are not very forthcoming with ingredient lists or mechanistic discussions regarding how their product works. Thus, I can only speculate that their products work in a similar manner to the ones with known aldehydes in them.

Early processes required the client to not get their hair wet for 4 days post-treatment and also required them to avoid deforming their hair in any way by wearing a hat, barrette, or even pushing it behind an ear. Some current treatments allow a much more flexible schedule than this, and a return to normal activity and grooming may be as soon as the next day.

Aftercare is quite specific as well, in that clients are admonished to never use any sulfate or sodium ion-containing shampoo or other products on their hair. Many salons offer a package of approved products for an additional (usually quite hefty) sum. I hypothesize that sodium ions dissolve the complex that holds the keratin to the hair, and thus causes the effects to rapidly erode and possibly leads to damaged or frizzy hair. If this is the case, I wonder if they have considered the effects a water softening system would have? The high sodium content in softened water would surely be as damaging as using a product with sodium in it.

As far as the heat goes, I have to say that temperatures that high can be incredibly damaging to hair. It causes water inside the hair to actually boil, which can cause ruptures in the hair shaft itself, leading to breakage and split ends. With the remarkable results reported by many, one can only assume that not everyone is as susceptible to this hazard as some. However, there are also many, many reports of people experiencing significant breakage and hair loss at the root. Some people have lost up to 60% of their hair after receiving this treatment. My concerns about this product type is that there seems to be insufficient testing and data at this time to fully understand how to achieve a consistent result.

I do not wish to gloss over the formaldehyde/aldehyde issue, but this article is already very long. I plan to delve more into that topic next month. I will say though that testing has found the levels of formaldehyde in these products to exceed the maximum levels approved by OSHA for exposure. Formaldehyde is a dangerous, carcinogenic substance and should not be taken lightly. I would like to explore this and the other aldehydes in more depth next month.

Some sample ingredient lists

Simply Smooth ingredients: Water, Hydrolyzed Keratin, Propylene Glycol, Vanillin , Cetrimoniun Chloride, Hydrolyzed Collagen, Cetearyl Alcohol, Ceteareth-20, Amodimethicone, Cyclopentasiloxane, Dimethicone, Imidazolidinyl Urea, Fragrance , Yellow 5 (Ci 19140), Orange 5 (Ci 15510)

Liquid Keratin 30 Day Straight Smooth Strong & Long Treatment: Purified Water , Dimethicone, Dimethiconol , Sodium Cocoyl Amino Acids (Aspartic Acid, Glutamic Acid, Alanine, Glycine) ,Biformyl, Potassium Dimethicone Peg-7 Panthenyl Phosphate , Keratin, Sodium Laneth-40 Maleate / Styrene Sulfonate Copolymer, Phenoxyethanol , Ethylhexylglycerin Laureth 4 , Laureth-23 , Hydrolyzed Keratin

QOD Cosmetics QOD GOLD: Cetyl Alcohol (organic co-emulsifier), Cetrimonium Chloride (emulsifier, anti-bacterial), Lanolin (ultra pure medical grade, hypoallergenic), Dimethicone (organo-substituted skin protectant), Bio-Organic Hydrolyzed Keratin Complex, Polyquaternium 7 (positively charged, patented), Methylparaben (naturally occurring antimicrobial), Propylparaben (antimicrobial), Urea (water soluble), Bio-Organic Hydrolyzed Keratin Complex (patented), Fragrance (natural, tropical fruit essence), CL 77480 (Pure 24 Karat Gold, medical grade), Aqua (purified), Cyclopentasiloxane (organically bound silicon), Dimethiconol (skin protectant, non toxic alternative to ozone depleting chemicals).