I'm new to retinoids — how do I start one gently without wrecking my skin?

If you're new to retinoids, ease one in slowly. With a form like retinaldehyde (retinal): patch-test first, begin with infrequent nighttime use, and expect a possible short adjustment period with mild dryness or flaking. Because the skin stores most of it as an inactive reserve and releases the active form only gradually, it tends to feel gentler than applying pure retinoic acid directly, and pairing it with barrier-supporting and hydrating ingredients such as niacinamide, ceramides and hyaluronic acid can help smooth that adjustment. Use it in the PM and always follow with a broad-spectrum sunscreen by day, since retinoids can increase sun sensitivity. If you are pregnant or breastfeeding, topical retinoids are generally set aside as a precaution, so it's best to consult a doctor. This is cosmetic reference for appearance and formulation, not medical advice. The concentration that matters is in the app.