Cystine Loss In Relaxed Hair – A Look At The Science

I don’t often like to write sciency posts but when looking at relaxers and the damage they can cause it’s important to understand it on a cellular level so that we can mitigate some of the damage.

Cystine is an amino acid derived from protein and researchers have found through amino acid analysis of hair after it has been relaxed that there were reductions in three amino acids specifically cystine, citrulline, and arginine. Cystine specifically is responsible for hair’s strength and is often found in low levels in people who suffer from hair loss.

Cystine levels go down with each subsequent relaxer application (for those think it’s a good idea to reapply relaxer to previously treated hair) which leads to brittle hair that breaks easily, no surprise there then. This should drive home the importance of using barrier creams or petroleum jelly* to prevent accidentally re-processing your hair.

It’s also worth pointing out that with the reduced amino acids in your relaxed hair, tensile strength is greatly reduced as well so keep styles that involve pulling your hair like braids, cornrows etc down to a minimum. I hear some relaxed ladies find that wearing a weave does not give them very good length retention, at best it’s a wash with the added growth cancelled out by the increased breakage during braiding. At the very least, if you enjoy weaves, use a stylist that you trust not to braid too tight!

Now, we know that cystine is reduced after your relaxer but how do you increase it’s levels? Supplemental cystine and has been shown in studies to increase the diametre of hair shafts in particular cases of hair loss. However this only applies if you have poor hair growth but does nothing for hair that has already been relaxed so the answer has to lie is topical application of some sort.