Choosing the best relaxer for black hair is the same as choosing a relaxer for any other type of hair. Hair type does generally differ between racial groups, but generalities should not be applied to individuals when it comes to using chemical relaxers. Instead, you need a basic understanding of how hair relaxing and perming work, as well as your hair type, so that you can make the most informed hair-relaxing choices.
The dense, tight curls of African or black hair are caused by variations in the diameter of the hair along the length of the hair shaft. Asian and Caucasian hair may also be curly and therefore have varying hair-shaft widths, but usually not as much as African hair. Mixed-race hair will have less variation in hair-shaft width than pure African hair. But from a practical point of view, our diverse culture presents many variations in hair type, even within racial groups. So only an individual evaluation of your hair can accurately predict how it will behave when exposed to chemical relaxers.
All chemical relaxers use strong alkaline chemicals to break the sulphide bonds between protein molecules in the hair. These bonds are what makes hair "remember" its natural shape. As the bonds are broken, the hair is reformed into the desired texture. During the neutralising step of the relaxing process, the proteins re-bond, creating a new permanent texture. Sulphide bonds also give hair its elasticity and resiliency, so chemical relaxing always causes some loss of hair strength. For black hair, the danger of over-processing lies in the fact that wider sections of the hair shaft absorb relaxer chemicals more slowly, while narrower sections may become damaged in that same amount of time.
The three main active ingredients found in chemical relaxers are sodium hydroxide, guanidine hydroxide and ammonium thioglycholate. Sodium hydroxide, commonly known as lye, has a reputation for causing hair damage, while guanidine hydroxide and ammonium thioglycholate are promoted as "gentle" or "no-lye" formulas. The truth, however, is that all three of these chemicals will cause severe hair and scalp damage if they are misused; and all three can produce good results when used correctly.
An experienced hairstylist is most qualified to identify which chemical relaxer is right for your hair. Of course, the texture and curl of your hair are key considerations in selection of product and processing time. But more importantly, your history of hair processing will determine which chemical relaxer can be used on your hair. Some relaxers, when combined with others, even when months have passed since your last relaxing process, will break protein bonds in such a way that disastrous hair breakage results.
No matter which chemical relaxer you use, timing is critical to success. The less time your hair is exposed to the chemical relaxer, the less damage will be done to it. So, less dramatic straight styles are a somewhat safer goal. A strand test is the best way to determine the correct amount of time for relaxing. The time selected should not be longer than the maximum limit suggested by the product manufacturer.
Many people successfully relax their own hair at home. But if you have no experience with chemical relaxers, are unsure of your hair type, or if your hair has been relaxed before, relying on an expert hairstylist in a salon is a safer option. Whether you relax your hair at home or in a salon, safety precautions include abstaining from wetting your hair for at least a week before relaxing, and an allergy test 48 hours prior to relaxing. Perform a strand test to determine processing time, and protect your scalp and adjacent skin with petroleum jelly or other emollient cream. Once the relaxer is applied, time it meticulously, and check your hair frequently. Wash the relaxer thoroughly from your hair as soon as the desired texture has been achieved.