Relaxers: How They Work and How to Use One

A relaxer permanently breaks the bonds that give hair its curl pattern, then reforms them in a straighter shape. Permanently is the important word: the change cannot be reversed, conditioned away or grown out of, only cut off. Everything else on this page follows from that, which is why the preparation matters more than the product.

Lye against no-lye

Lye relaxers use sodium hydroxide. They work faster, straighten more thoroughly, and rinse out more cleanly, and they are harsher on the scalp. No-lye relaxers use calcium hydroxide with an activator. They are gentler on the skin, which is why most home kits are no-lye, and they leave calcium deposits on the hair that build up over time and leave it feeling dry and coated. If you use no-lye, a chelating shampoo periodically is what removes those deposits, and it makes a noticeable difference to how the hair feels.

Test before you commit

Two tests, both worth the time. A patch test on the skin behind the ear, twenty-four hours ahead, tells you whether you react to the product. A strand test on a small hidden section tells you how long your hair takes to process and what the result will look like. Processing time varies with texture, density and previous treatments far more than the box allows for, and the strand test is the only way to know your number rather than the average.

Protecting the scalp

Do not wash your hair for several days beforehand. The natural oil on the scalp is protection, and a freshly washed scalp is a bare one. Do not scratch, and do not relax over a scalp with cuts, scratches or irritation. Apply a base cream over the scalp, and especially along the hairline, nape and ears, where the skin is thinnest and the hair finest. Wear gloves.

Timing decides everything

Apply quickly and evenly, work from the back where the hair is coarsest toward the front where it is finest, and smooth rather than comb. Watch the clock from the first application, not the last. Over-processing is where relaxers do their damage, and it happens in minutes. If the scalp burns at any point, rinse immediately and completely. Burning is not part of the process, and enduring it produces chemical burns and scarring, not straighter hair.

Neutralizing and aftercare

Rinse thoroughly with warm water, then use the neutralizing shampoo that came with the kit, repeatedly, until it stops changing color or until you have washed at least three times. Unneutralized relaxer keeps working. Follow with a deep conditioner, and a protein treatment within the first week, since relaxed hair has lost structure and needs it. Do not color, and do not apply heat, in the days immediately after.