rin, do you use a glycolic cream/moisturiser as well? what strength glycolic did you have at the spa?
No, this is the only thing that I use that has glycolic acid in it. Everything else I use is very mild, like cetaphil and tea tree oil toner, etc.. I got the 40% strength one, because I read that it's just right. 30% would be okay if your skin is reeaally sensitive and you want to start light, and 50% might be too much for my skin.