hydroqartozone? if thats what your talking about, yes it can be dangerous as it is a steroid and it can thin the skin over time.
There are tons of products for hyper pigmentation. Do you have pitted scarring aswell? if yes, there are two products by clinic that are good. one is a get even product (dont remember which.. sry) and another i was told was available is stick format. ill try to enquire and get back to you.
for simple hyperpigementation, most products with vitamine c or rentanoid or rentenole. Ie ole's collagen serum, help me by philosophy or miracle woker by philosophy. Anything to lighten or to encrease cellular turnover will help.
For those unclear on what cell turnover means exactly, this how it was explained to me....
When you are a kid and you get a cut your wound heals withen a day or 2. As a 25 year old, my similar cuts have well over a week. It is because my cell turnover has slowed. Many anti aging products claim to help speed this up, or keep it at a good rate. This will help deminish wrinkles, expression lines, lighgten sun spots, acne scaring and provide an all over glow.
peels will always help with hyperpigmenation. again, i always suggest ole.