I have dark underarms, groin, elbows, knees, and mouth corners. Can COSMELAN help me? 25 y/o Female with light olive skin tone

Hello,It sounds like you have done your research to rule out the possibility of an underlying condition.  Hyperpigmentation (darkening of skin) may be related to several factors, and ruling out anything concerning is important.Olive colored skin (and most skin types) generally respond better to a gentle approach in fading out color.  Harsh treatments or products may actually exacerbate the problem.  Using chemical peels, PRP, and other modalities seem quite extreme or not proven to be therapeutic for hyperpigmentation.  Our recommendation is a gentle bleaching product using hydroquinone in 6 or 8% concentration.  We also discourage retinoids in the preparation as this is too harsh and not needed.  If you are not responding after 4 weeks using a topical regimen, using a non-ablative Q-switched YAG laser is the next best option with or without a topical program.  Always start with the least expensive, but known to be of value, treatment plan.Please see our below link for the treatment of hyperpigmentation.

The Melarase Brightening Kit can help reduce pigmentation and discoloration on the skin. Clear and Brilliant laser can further enhance benefits. 
Best, 
Dr. Karamanoukian
Los Angeles

This is difficult to determine without pictures and needs an in-person evaluation. Cosmelan may help give improvement, but a combination is needed to get the most improvement. Hyperpigmenation can be improved with a combination of lasers, Aerolase, microneedling/prp, skin lightening, peels, and skin care. Sun protection is essential. I recommend getting a formal evaluation with a cosmetic dermatologist. Best, Dr. Emer