The mechanisms of action of Hydroquinone include: (i) reversible inhibition of tyrosinase (the main enzyme involved in the conversion of tyrosine to melanin); and (ii) selective damage to melansomes and melanocytes.

Mometasone is a glucocorticoid (steroid) that relieves itching and inflammation of eczema, dermatitis, allergy and other skin rashes.

Tretinoin in acne is due primarily to its ability to modify abnormal follicular keratinization.