Hair relaxers contain chemicals so potent you have to wear gloves to apply them. While these products change the structure of curly, kinky or wavy hair to make it more manageable, they can also severely damage your scalp and hair, notes Pamela Ferrell, author of “Let’s Talk Hair.” In some cases, this damage can be permanent and cause permanent hair loss.
In 1910, Garrett Augustus Morgan, son of former slaves and the inventor of the automatic traffic signal, accidentally discovered what would become known as hair relaxers. One day, during his search for a lubricating liquid for sewing machine needles, Morgan wiped his hands on a wool cloth, according to Skin Biology. When he returned the following day, the fibers of the woolly cloth had smoothed out. Morgan identified the chemical that straightened the fibers and first marketed it as a “hair refining cream.”
Hair relaxers contain several corrosive chemicals that break down the hair structure and can damage scalp. At pH 12, they share the same alkalinity of household products such as ammonia. By contrast, the alkalinity of skin and hair is pH 5. The most potent ingredient found in hair relaxers is sodium hydroxide or caustic soda lye, which is also found in liquid drain cleaners and paint thinners. Even products marketed as “no lye” contain damaging ingredients such as calcium hydroxide or guanidine carbonate, which you’ll find in “organic” brands. Calcium hydroxide is used to clean up water and sewage and guanidine carbonate is an ingredient in hair removal products.
Sodium hydroxide can cause chemical burns, permanent injury and scarring on unprotected human tissue. Along with other chemicals found in relaxers, sodium hydroxide can leave your scalp itchy, red and flaky and cause scalp dermatitis, according to Ferrell. They also dry out your hair and make it brittle, which increases breakage and hair loss.
The side effects of hair relaxers are often worse because of improper application, explains the U.S. Food and Drug Administration. To minimize the damage to your scalp and hair, never leave a hair relaxer on for more than the recommended amount of time. View labels for product-specific application. Also, do reapplications or “touch-ups” only every six to eight weeks, depending on how quickly your hair grows. During a touch-up, apply relaxer only to new growth, not previously straightened hair.
Other ways to minimize damage include applying a protective gel -- such as petroleum jelly -- to your scalp before a relaxer and a pre-relaxer treatment to previously relaxed hair. Do not wash your hair for at least a week before applying a relaxer.