Retinol, retinal, tretinoin — a working guide to skincare's most evidence-backed family, and how to start without wrecking your skin barrier.
If dermatology has a favourite molecule, it is vitamin A. Retinoids remain the most evidence-backed topical for acne, texture and photo-ageing — and the most commonly abandoned, because almost everyone starts them wrong.
The family tree
Retinol and retinal (over the counter) must convert in the skin before they work; tretinoin (prescription) arrives ready. More conversion steps mean gentler — and slower.
Starting without the misery
Twice a week, a pea for the whole face, moisturiser before and after. Increase frequency only when your skin stops noticing. The purge is real but temporary; sunscreen every morning is non-negotiable.
Give it twelve weeks before judging. Skin cells need a full cycle to show you what the molecule can do.