Knowing these basic terms can be key to conditioning your curls properly.

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.