What are chemical relaxers and how do chemical relaxers work to straighten hair?

May 31, 2017

What are chemical relaxers and how do chemical relaxers work to straighten hair?

The first hair relaxer was invented by Garret Morgan in the early 1900’s.  He was the first to use alkaline products to straighten black hair.  The first commercial chemical relaxers were introduced in the early 1970’s and soon became the most popular method to straighten hair.  Also known as perms, chemical relaxers work by using various chemicals to break the disulfide bonds to chemically straighten hair.  The chosen chemical relaxer, in the form of a thick cream, is combed through the tightly coiled hair, breaks the disulfide bonds, and straightens the hair.  This process is typically repeated at 6-12 week intervals to the areas of new growth.  Sodium hydroxide is the most effective chemical relaxer.  Also known as “lye” relaxers, if left on the scalp for extended periods of time, lye relaxers can cause superficial self limited burns to the scalp.  For this reason, “no lye” relaxers were introduced in the 1970’s .  They are less irritating to the scalp but can be more drying to the hair.  These no lye relaxers typically utilize guanidine hydroxide to straighten the hair. “ Kiddie perms” usually contain guanidine hydroxide.   “Kiddie perms” also gained popularity in young children in the 1970’s and in one study, 46% of women reported their first hair relaxer between the ages of 4 and 8 years old.

Although, 60-70% of African American women use or have used chemical relaxers, these hair straighteners are not without side effects.  Over-processed hair can lead to breakage and, in general, chemically relaxed hair is more prone to breakage than natural untreated hair.  This may be because the levels of cysteine are dramatically reduced in chemically relaxed hair.  Cysteine is an amino acid that is an important component of disulfide bonds.  As cysteine levels in the hair decrease, hair fragility and breakage increase.  One South African Study showed that the distal tips of chemically relaxed hairs had a 75% reduction in cysteine when compared to natural untreated hair.  Did you know that traction alopecia (thinning at the edges and hairline) occurs more frequently in chemically relaxed hair?  Recent studies have shown that cornrows or braids on chemically relaxed hair can increase the risk of traction alopecia by five times.  So what is the take home verdict on chemical relaxers?  They have been around for years and, if done correctly, they can be utilized to safely and effectively straighten the hair.  However, keep in mind, over-processing can severely damaged hair and should be avoided.