Dr. Mona Gohara's Nighttime Skin-Care Routine "Then, I apply a pea-size amount of a retinoid gel or lotion. I go between over-the-counter Differin Adapalene Gel 0.1% Acne Treatment ($13) and prescription Tazorac Gel. Retinoids build collagen in the skin, the gel vehicle absorbs excess oils." Image Source: target.com Differin Adapalene Gel 0.1% Acne Treatment $13 from target.com Buy Now