No-Lye No-Mix relaxers are based on lithium hydroxide as an active ingredient while other ingredients in the relaxer cream are very similar to Lye relaxers. The reaction of lithium hydroxide with the excessively curly hair is also similar to Lye and No-Lye relaxers. The one-third of the cystine bonds of the hair change to lanthionine bonds, leaving two-thirds of the cystine bonds still in tact.
The major advantage of lithium hydroxide over sodium or potassium hydroxide is that it is slightly less irritating to the scalp than sodium or potassium hydroxide.
However, lithium hydroxide is not as effective in straightening excessively curly hair and in order to achieve acceptable level of straightening, more lithium hydroxide has to be added to the cream relaxer formula.
The United States Food and Drug Administration (FDA) considers lithium hydroxide relaxers as no-lye relaxers and the manufacturers of relaxers call this category as a No-Lye and No-Mix relaxer to exploit this fact. This relaxer system is not as efficient in straightening hair as sodium, potassium, or guanidine hydroxides, which is probably why this type of relaxer system enjoys limited success in the market place.