What unique ingredient was featured in the first commercial "no lye relaxer" introduced by Pro line in 1917?

The first commercial "no lye relaxer" introduced by Pro Line in 1917 featured potassium hydroxide as its unique ingredient. Potassium hydroxide is a less harsh alternative to sodium hydroxide, which has been traditionally used in many relaxers. The introduction of potassium hydroxide marked a significant innovation in hair care, providing a chemical relaxer that could effectively straighten hair without the damaging effects associated with traditional lye-based relaxers. This made it a popular choice for clients seeking smoother hair while minimizing potential scalp irritation and hair damage. The formulation of potassium hydroxide allowed for a gentler approach, appealing to a wider audience and leading to advancements in relaxer technology in subsequent years.