[Routine Help] Which PIH treatment should I start with first?

Beauty Tips For Body Care
Hydroquinone? Vitamin C? Niacinamide?My current routine:AMNeutrogena gentle cleanserNeutrogena gel moisturiserBiore aqua rich sunscreenPMNeutrogena gentle cleanserDr.Douxi 5% Mandelic acidNeutrogena gel moisturiser (PM)Tretinoin 0.05%I repeat the same routine daily.It's been about a week since I introduced the AHA into my routine, with no issues at all- no burning, flaking or anything of the sort. Is it too soon to be looking for a PIH treatment now?Thanks!
Girls Blog 2015
Submitted by Thranrond