Retinol
Caution
A vitamin A derivative with strong evidence for smoothing lines and improving texture. Often irritating at first; use at night with sunscreen by day, and avoid during pregnancy.
What it does
Active. Does something to the skin: exfoliating acids, retinoids, vitamins, peptides, soothing agents.
Worth knowing
Can irritate or dry out skin, especially at higher strength or in leave-on products.