I have dehydrated combination skin and often has congested pores under my chin and I’ve noticed tiny bumps on my forehead. I’m new to the acid game, so I just used it twice in a week (used like a toner with cotton balls). It doesn’t sting for the most part, but stings at 2 spots on my face that I think probably due to barrier issues. Maybe I should try PHA first, but this thing really cleared up my skin. No more bumps on my forehead after a week, and my chin area is looking clearer as well. Maybe I’ll try to use it as a mask (And wash after) to avoid stinging/irritation