Tretinoin (Retin-A)

Tretinoin is a prescription cream, gel, or lotion made from vitamin A. It belongs to a family of ingredients called retinoids. You may know its weaker, non-prescription relative, retinol — tretinoin is the stronger, medical-grade version that a doctor has to prescribe.

It does two jobs well. First, it treats acne by keeping pores from clogging. Second, it is one of the only topical treatments proven to reverse signs of sun damage — fine lines, rough texture, and dark spots — by getting skin to make new collagen.

Tretinoin is not a quick fix. Acne usually improves over 6 to 12 weeks, and anti-aging results take several months of steady use. The trade-off for that patience is a treatment with more real evidence behind it than almost anything else you can put on your skin.

Tretinoin speeds up your skin's natural cell cycle. It tells skin cells to grow and shed faster, so dead cells slough off instead of piling up and plugging pores. That is why it clears and prevents acne.

At the same time, it works deeper in the skin to switch on collagen production. Collagen is the protein that keeps skin firm and smooth. Sun damage breaks it down over the years; tretinoin helps rebuild it, which is how it softens fine lines and evens out tone and texture.

The same fast turnover that helps your skin is also why it irritates at first. New skin cells are reaching the surface before they are fully ready, so skin can look dry, pink, and flaky for the first few weeks. This settles as your skin adjusts — a process people often call "retinizing."

Educational only — your dermatologist will tailor this to your skin.

How much: A pea-sized amount is enough for the whole face. More does not work faster — it just causes more irritation.

When: At night. Tretinoin breaks down in sunlight and makes skin more sun-sensitive, so it is a bedtime product.

How to apply: Wash with a gentle cleanser and let skin dry fully — about 20 to 30 minutes. Applying to damp skin drives it in deeper and stings more. Then dot the pea-sized amount over your face and spread a thin layer, avoiding the corners of the eyes, nostrils, and lips.

Start slow. Most dermatologists suggest 2 to 3 nights a week for the first few weeks, then build up to nightly as your skin tolerates it. This is the single best way to avoid a harsh peeling phase.

Moisturize and protect. A plain moisturizer helps with dryness — you can even apply it before or after tretinoin (the "sandwich" method) to buffer irritation. Daily sunscreen is not optional; skin on tretinoin burns more easily, and sun undoes the anti-aging benefit.

Be patient. Acne often gets a little worse before it gets better (see the "purge," below). Give it a full 12 weeks before judging results.

These are expected, especially in the first 2 to 6 weeks, and ease as skin adjusts.

Dryness and peeling. The most common effect. A gentle cleanser and a good moisturizer handle most of it.

Redness and stinging. Skin can look pink and feel tight or tingly after applying. Starting slowly keeps this mild.

The "purge." Acne may flare in the first few weeks as tretinoin pushes clogged pores to the surface faster. This is normal, it is not a sign of failure, and it usually settles within a month or two. Don't quit during the purge.

Sun sensitivity. Skin burns more easily. Daily sunscreen is essential.

Increased sensitivity to wind, cold, and other products. Harsh scrubs, strong acids, and alcohol-based toners will sting more while you're using it.