I had been in search of a replacement for the VitalePro High Comfort relaxer system. I was looking for a lye relaxer that was tolerable to sensitive scalps. So far, Syntonics straightens without much irritation. I used the "mild" relaxer strength. I only relaxed a few symmetric patches of hair around my hairline. I rinsed the relaxer out with my face down so that runoff water did not get into the rest of my locked hair. My plan was to texturize versus making my hair too straight. So far, it passes my initial testing requirements.
NOTE: The neutralizing shampoo and conditioner both have soothing/cooling properties built in. Some people will love it. Others may not.