Cosmelan. Is it a chemical peel procedure?

Yes. The cosmelan peel is a gentle, effective chemical peel for even the most stubborn skin pigmentation. Unlike most chemical peels, the cosmelan peel does not cause sensitivity to the sun, so you do not have to risk your treatment being set back by sun damage. The ingredients in cosmelan regulate your skin’s melanin activity, resulting in slower, more even melanin production.
Yes. Cosmelan is a chemical peel commonly used to treat facial pigmentation issues like melasma (pregnancy mask), supposedly by inhibiting tyrosinase, an enzyme in the pigment-formation process. It is very expensive, and i know of no credible evidence that it works any better than more common (and cheaper) chemical and mechanical peel procedures.