Choosing the best at-home hair relaxer for white hair is no different than choosing a relaxer for any other type of hair. Hair relaxers are marketed mostly to people of African descent because that's the demographic that buys most of the product. But hair relaxers will work on hair of all ethnic types. There are some general racial differences in hair, but when it comes to hair relaxing, it's far more important to consider the individual's hair.
The dense tight curls and waves of African Americans' 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, though it may appear very curly, will have less variation in hair shaft width than pure African hair. Of course, these are generalities. The hair of a person within any race may vary significantly from the norm.
An evaluation of hair texture and history of prior processing is essential to at-home relaxing success, no matter what ethnicity your hair. In general, fine textured or heat damaged hair will need less relaxing time than course hair. Always do a strand test before using an at-home relaxer, even if you have used the same relaxer before. Consult a professional before relaxing color treated or previously relaxed hair. Hair that has already been processed requires special consideration, especially in product selection.
With white or Caucasian hair, some hair stylists recommend relaxers with the active ingredients ammonium thioglycholate or guanidine hydroxide. These products are commonly called "no lye" relaxers. They are gentler than relaxers that contain sodium hydroxide, and therefore easier to control on fine textured or delicate hair. However, amonium thioglycholate and guanidine hydroxide break down hair protein bonds according to the same chemical principles as sodium hydroxide. So no-lye relaxers will also damage hair if used improperly.
Home hair relaxers straighten hair by permanently rearranging the protein structure of the hair shaft. Strong alkaline chemicals are applied to the hair to break the sulfide bonds that hold the protein molecules together. The hair is combed straight and the chemicals are allowed to act for several minutes. The relaxer is rinsed from the hair and a neutralizing chemical is applied to the hair to stop the bond breaking process.
Relaxing hair, at home or in the salon, always results in some damage to the hair. To minimize damage, relaxing must be timed precisely, the hair checked frequently, and the relaxer removed from the hair immediately once hair is straight. Miscalculation of application time or misjudging hair condition can result in significant hair breakage and even temporary bald patches. Having your hair relaxed by an experienced professional is always safer.