I've been using tretinoin cream (0.05 %) for a month now every single night without experiencing much irritation - occasional flaking disappeared quickly, no redness. Now I am considering exfolianting with AHA (10 % glycolic) every other night instead of tretinoin. I am not sure if that would bring any benefit to my routine, as I don't have sun damaged skin. I use a ZnO sunblock every day as well as an antioxidant serums (AM CE Ferulic by SkinCeuticals, PM green tea). I am 22 yo. Thank you!