Tr
Tretinoin
Tretinoin · Retinoic AcidActive
The active form of vitamin A, available by prescription. Used for acne, sun damage and uneven tone.
What it does
It’s the form of vitamin A that does the work, so your skin doesn’t have to convert it the way it does retinol. That makes it much stronger, and it usually irritates more than retinol at first.
The evidence, graded
strongNo topical retinoid is recommended in pregnancy. The class covers tretinoin, adapalene, tazarotene, trifarotene, retinol, retinaldehyde, retinyl palmitate and hydroxypinacolone retinoate. Studies of accidental exposure, mostly to tretinoin and adapalene early in pregnancy, are reassuring. They are not strong enough to recommend any retinoid in pregnancy. The caution extends to the other retinoids as a class-effect. Oral isotretinoin is a separate case, with an absolute contraindication.ACOG 2022 · ACOG patient FAQ ↗
expert consensusAlternate tretinoin and the acid by night, or split them across the day. Tretinoin is described as the most potent of the retinoids, more irritating than retinol, and acids irritate on their own. No study Drop has read applied the two to the same skin, so that they compound is a careful assumption, not a measurement.Mukherjee 2006 · Clinical Interventions in Aging ↗
expert consensusFine together. Both reviews call azelaic acid well tolerated; neither used it with a retinoid, and nothing Drop has read shows it calming retinoid irritation.Sieber 2014 · Skin Pharmacology and Physiology ↗
expert consensusUse mandelic acid and a retinoid on alternate nights: the acid and the retinoid each irritate skin on their own, and nobody measured the two together. Mandelic acid appears in neither review Drop read for this pair, so the common line that it is the gentlest AHA is not something Drop can stand behind.Kornhauser 2010 · Clinical and Cosmetic Investigative Dermatology ↗
expert consensusFine together — moisturizer before and after tretinoin (the “sandwich method”) is a common way to ease into it. If it still stings, ask whoever prescribed it about using it on fewer nights: that’s the step the research backs, and irritation is why people give up on retinoids.Mukherjee 2006 · Clinical Interventions in Aging ↗
expert consensusWhile breastfeeding, NIH's LactMed rates topical tretinoin as low risk to the baby and adapalene as probably low risk, because little is absorbed through the skin. Both come with the same care: keep them off the nipple and breast, and keep your baby's skin off the skin you treated. A 2023 review agrees that topical retinoids become acceptable while breastfeeding. This covers these two only. Retinol, retinal and the other retinoids in skincare products are still best avoided while breastfeeding.Drugs 2024 · LactMed, National Institute of Child Health and Human Development (NCBI Bookshelf) ↗
expert consensusUnder 18, Drop does not suggest a retinoid to prevent aging. No source Drop has read tested one for that in anyone under 18, and the only under-18 data in the retinoid review it cites comes from people with acne. Acne is different: the American Academy of Dermatology's acne guideline covers patients from age 9 and strongly recommends topical retinoids for acne. That is a conversation with a doctor.Motamedi 2022 · Journal of Cutaneous Medicine and Surgery ↗
emergingFine in one routine if split — benzoyl peroxide in the morning, tretinoin at night. Mixed with benzoyl peroxide and left in light, tretinoin lost more than half its strength in about two hours and 95% in a day. That was a lab mixture, not skin. A product that contains both is used as its label says.Martin 1998 · British Journal of Dermatology ↗
emergingFine together — one of Drop's sources reports two small studies of a product containing both, used twice daily for three and six months, that improved aged and photoaged skin. If the pair stings, vitamin C in the morning and retinol at night is a comfort choice, not a rule. A vitamin C serum is acidic (L-ascorbic acid has to be formulated below pH 3.5 to get into skin). Whether that makes retinol sting more is untested; no study Drop has read measured it.Pinnell 2001 · Dermatologic Surgery ↗
emergingFine together — in one study, a niacinamide moisturizer eased the start of a retinoid. People used it on one side of the face and a plain one on the other, then started tretinoin on both sides two weeks later. The authors conclude that side got through the first weeks more easily and responded better. That moisturizer also held panthenol and vitamin E, and the retinoid was tretinoin, not retinol.Draelos 2006 · Cutis ↗
Graded per the methodology: strong · moderate · emerging · expert consensus. A weak source on a strong claim gets the weaker label.
Also known as
all-trans retinoic acid, retin-a
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