Blonde girl swimming in the water.

Swimming before using a chemical hair relaxer has traditionally been a no-no. But these days, we have "no lye" formula relaxers and chlorine-free pools. So you may wonder if it's now OK to go swimming before you relax your hair. As it turns out, conventional hairdressers' wisdom still applies. Once you understand how chemical hair relaxers affect your hair and your scalp, you'll know why you should postpone that dip in the pool.


When you make an appointment to have your hair chemically relaxed, your hairstylist will tell you not to shampoo or go swimming for at least a week before the appointment. This is true for all chemical relaxing processes, including thermal reconditioning. At your appointment, before any chemicals are applied to your hair, your hairstylist will ask about products you've used, like relaxers and hair color, that contain harsh chemicals. With this information, your hairstylist can select the right chemical-relaxer formula for your hair and calculate the proper application time.


Chemical hair relaxing is a two-step process. First, a strong, alkaline chemical like sodium hydroxide, amonium thioglycoloate or guanidine hydroxide is applied to break down the bonds between the protein molecules--called keratin--in hair. These bonds--called sulfide bonds--are responsible for giving hair "memory" for its natural shape. As the sulfide bonds break, the hair straightens. A neutralizing solution is applied to stop the bond-breaking process and allow the proteins to rebond in their new, straight shape.


As the hair straightens, it also becomes weaker. This is because sulfide bonds are also what make hair strong, and once broken, they don't reform to the same extent as in unprocessed hair. Skin proteins are also vulnerable to chemical relaxers, so unprotected skin can become irritated. Your scalp's natural oils provide some protection for your skin during chemical hair relaxing. This natural barrier is important even if a protective cream or lotion is also used. Natural oils also help mitigate hair damage by reducing the porosity of your hair. Less porous hair absorbs the chemical relaxer more slowly and evenly, making it easier to control application time and reducing the chances of hair damage from over-processing.


Activities like shampooing, swimming or even rinsing your hair in plain water can remove oils from your hair and scalp. So these activities should be avoided for at least 1 week before using a chemical hair relaxer. However, staying out of the swimming pool is not the only precaution you should take. Also avoid excessive sun exposure and hairstyling products, as these can cause scalp sensitivity and change how the relaxing chemicals act on your hair. If you have any known skin conditions or take prescription medications that increase skin sensitivity, ask your doctor if chemical hair relaxing is advisable for you.


After you have used a chemical hair relaxer, your hair is more susceptible to damage from swimming-pool chlorine. You should wait a minimum of 48 hours before going in the pool. In general, your hair will maintain better condition if you protect it from swimming-pool water with a swim cap and pre-swim conditioner. Always wash and condition your relaxed hair after swimming in a chlorinated pool.