What to look for on the label: If it's a prescription: tretinoin (brand names Atralin, Avita, Retin-A, Retin-A Micro, Renova), tazarotene (Avage, Tazorac) and adapalene (Differin). If it's over-the-counter: retinol, which minimizes lines and discoloration more slowly than its prescription counterparts (12 weeks, not six, before you see improvements).
For best results: Allow your skin to become accustomed to a retinoid, which can cause redness, flaking, and peeling. Start by applying it every third night (because it's sensitive to sunlight, don't apply in the morning). After two weeks, apply every other night. If you're not dry or flaky after another two weeks, use it every night. Wait 15 minutes after washing your face before applying (if skin is damp, the retinoid could be absorbed too quickly and cause irritation). Never use more than a pea-size dab for your whole face; if your skin is dry, you can apply a moisturizer on top.
You should know: Don't layer a retinoid with benzoyl peroxide or alpha hydroxy acids because they will deactivate it.
Philosophy Miracle Worker Miraculous Anti-Aging Retinoid Eye Repair ($65; philosophy.com)
SkinMedica Tri-Retinol Complex ($55; skinmedica.com)