Triple topical therapy is first-line treatment that is often effective and consists of a combination of Hydroquinone 2 to 4% Tretinoin 0.05 to 1% A class V to VII topical corticosteroid (see Table: Relative Potency of Selected Topical Corticosteroids) Hydroquinone depigments the skin by blocking the enzymatic oxidation of tyrosine 3, 4-dihydroxyphenylalanine (DOPA) and inhibiting melanocyte metabolic processes.