In today’s Science Corner we thought we’d delve into the world of relaxers and texturizers to shed some light on what this kind of chemical treatment entails.

Chemical treatments of this nature involve the permanent alteration of the hair’s keratin molecules which are composed of strong bonds (disulfide bonds) and weak bonds (hydrogen bonds). Disruption of disulfide bonds that maintain the coiled/curled/wavy shape of textured hair, results in permanent alteration of the hair’s texture.

Chemical relaxers are made of highly alkaline chemicals which facilitate the opening of the hair cuticle scales by swelling the hair shaft. This allows for penetration of the straightening agents into the cortex. Based on the active ingredient, chemical relaxers can be separated into two categories: lye and no-lye relaxers.

The active ingredient in lye relaxers is sodium hydroxide, which results in a very alkaline pH of 13–14. Lye relaxers have been purported to be less drying and damaging to the hair because they do not leave mineral deposits, which impede moisture absorption, on the hair shaft. However, they are more irritating to the scalp and can quickly cause chemical burns.

On the other hand No-Lye relaxers typically contain guanidine or lithium hydroxide and are available in mix or no-mix formulations. No-lye relaxers are less irritating to the scalp; however, they leave behind small amounts of calcium deposits that increase the brittleness of the hair. Chelating shampoos are often required for effective removal of these deposits

PRO TIP: Relaxers should not be applied directly to the scalp but only to the hair shaft!

What's the difference and how do these products work?

Texturizing is very similar to chemical relaxing, however, it is formulated to “loosen” the natural curl pattern of the hair instead of completely straightening it. Texturizers and relaxers are often marketed as completely different hair care products, with texturizers sometimes advertised as “natural” or “safer” alternatives to chemical relaxers. However, it should be emphasized that most texturizers contain active ingredients identical to those found in chemical relaxers and both products permanently and irreversibly change the cleavage of disulfide bonds within the hair’s keratin molecules. The main differences are that texturizers are left on the hair for a shorter period of time (typically 5-10 minutes) and are usually less alkaline chemical straighteners that selectively weaken the hair’s disulfide bonds instead of breaking them, resulting in more loosely coiled strands. One of the main disadvantages of texturizers is the difficulty in maintaining a uniform texture with each reapplication.

Texlaxing is a relatively newer technique used to achieve texturized hair but involves the use of traditional chemical relaxers (instead of products labeled as texturizers). The aim is to deliberately under-process hair and this is typically achieved by diluting the consistency of chemical relaxers by adding oils or conditioners, which prolong the processing time for disulfide bond breakage.

Is relaxed hair unhealthy?

The simple answer is it is possible to have healthy relaxed hair. By objective scientific standards, relaxed hair may be viewed as unhealthy because the breakage of disulfide bonds associated with chemical straightening increases the fragility of the hair shaft. In a study comparing the tensile strength (i.e. how strong a hair strand based on how much pull it can withstand before it breaks) of virgin African hair to its relaxed equivalent, virgin hair it is 5500 times, in comparison relaxed hair is only 550 times. This doesn’t mean relaxed hair can’t grow long or ‘healthy’ - it depends on how you style your hair, your lifestyle, hair goals and time/money commitment. Relaxed hair tends to require more money and regular professional visits for upkeep. And if you’re someone who enjoys manipulating your hair frequently and playing around with colour

Reference: Aguh C and Okoye G.A (2017). Fundamentals of Ethnic Hair, The Dermatologist's Perspective.

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