#retinoid

The acid-plus-retinoid layering myth: pH math and the night-cycling alternative

TL;DR: The ‘never mix acids and retinoids’ rule originated from skin-cycling logic and from concern that the low pH needed for AHA…

Adapalene is the cheap prescription retinoid the FDA quietly made OTC

TL;DR: Differin gel was prescription-only for twenty years. In 2016 the FDA moved adapalene 0.1 percent gel to over-the-counter status with almost…