We've all heard about Lye or No-lye relaxers and how one is better than the other. I will explain how these two affect your hair.

Before I go any further, I will like to define pH.
In Chemistry, pH (potential of hydrogen) is a numeric scale that runs from 0 to 14. 0 been the most acidic and 14 been the most basic of an aqueous solution. 7 is neutral.

About Lye Relaxers

The active ingredient in a lye-based relaxer is sodium hydroxide (NaOH). The pH level is higher in a lye relaxer than a no-lye relaxer. The pH is 12-14 for lye, 9-11 for no-lye. Your hair have a pH of around 4-5. Does this higher pH make a lye relaxer worse for your hair?

A lye relaxer works to break down the hair's bonds more quickly, which is good because you often experience more scalp irritation with this chemical; the faster it works, the sooner you can rinse it out. However, these tend to rinse cleanly and quickly with a good neutralizing shampoo follow-up.

No-Lye Relaxers.

The active ingredient in a no-lye based relaxer is calcium hydroxide (CaOH) or guanidine hydroxide. 
Although the pH level of a no-lye relaxer is typically lower than a lye-based one, no-lye relaxers are often associated with dryer hair due to potential calcium buildup.

One of the major reasons someone may prefer a no-lye relaxer is if her scalp is sensitive, as the chemicals in this type of relaxer can be milder on the scalp. This doesn't mean that it's better to use on children or that the chemicals cannot burn you (they can).

Unfortunately, people sometimes make the mistake of leaving a no-lye relaxer on the hair for too long, leading to dry, dull hair due to over-processing.

To remove calcium buildup, try a clarifying shampoo once a month or so to remove dulling deposits. Since clarifying cleansers are often drying, a deep conditioning treatment should be a regular part of your hair care routine.

While clarifying and deep conditioning are important for keeping no-lye relaxer-treated hair in good shape, deep conditioning is also necessary for lye relaxer-treated tresses.

The bottom line is that all relaxers contain chemicals that break down the hair's natural bonds in order to straighten it and that one relaxer doesn't fit everyone's needs. It's best to consult with a professional to determine what your particular needs are when it comes to relaxers.