Tretinoin is all-trans retinoic acid, the active acid form of vitamin A. Applied to the skin as a cream, gel or lotion, it is a prescription treatment for acne vulgaris (Retin-A, Retin-A Micro, Altreno and many generics) and, as Renova 0.02% cream, an add-on treatment for fine facial wrinkles from sun damage. It has been on the US market since the first Retin-A approval in 1971.
Tretinoin is not the same drug as isotretinoin (Accutane). Isotretinoin is 13-cis retinoic acid, a different form of the same molecule, taken by mouth for severe nodular acne under a strict pregnancy-prevention program. It has its own page: Isotretinoin (Accutane). Tretinoin also exists as an oral capsule, but only as a cancer drug for acute promyelocytic leukemia, with its own boxed warning (covered briefly below).
This page summarizes what the FDA labels, clinical trials and the American Academy of Dermatology (AAD) guideline report about topical tretinoin. It is for education only and is not medical advice.
| Property | Detail |
|---|---|
| Drug class | Retinoid (vitamin A derivative); all-trans retinoic acid |
| Topical brands | Retin-A cream and gel, Retin-A Micro gel, Renova cream, Altreno lotion; many generics |
| First US approval | Retin-A solution, NDA 016921, October 20, 1971 |
| Route | Topical (skin); a separate oral capsule is approved only for leukemia |
| Topical strengths | 0.01–0.1% depending on product (cream, gel, microsphere gel, lotion) |
| Labeled topical dosing | Thin layer once daily, usually in the evening |
| Systemic absorption | About 0.8–1.4% of a 0.1% gel dose in healthy volunteers (Retin-A Micro label) |
| Half-life | Not reported for topical use; oral tretinoin 0.5–2 h in leukemia patients (capsule label) |
| US status | Prescription only; not a controlled substance |
| WADA status | Not named on the WADA 2026 Prohibited List |
What it is
Tretinoin’s chemical formula is C₂₀H₂₈O₂ with a molecular weight of 300.4 g/mol (PubChem). It is a natural metabolite of vitamin A that the body makes in small amounts. Topical products deliver it to the skin at concentrations well above normal physiological levels (Renova label).
The retinoic acid family includes several forms that share the same formula but differ in shape. That matters, because they are separate drugs with different routes, uses and risks:
| Compound | Chemistry | Main US use | Route |
|---|---|---|---|
| Tretinoin | All-trans retinoic acid | Acne; fine wrinkles from sun damage | Topical |
| Tretinoin capsules | All-trans retinoic acid | Acute promyelocytic leukemia (APL) | Oral |
| Isotretinoin (Accutane) | 13-cis retinoic acid | Severe recalcitrant nodular acne | Oral, iPLEDGE program only |
| Adapalene (Differin) | Synthetic naphthoic-acid retinoid, not built on the vitamin A chain | Acne | Topical |
Sources: Retin-A label, tretinoin capsules label, Accutane label.
How it works
Tretinoin binds to and activates three retinoic acid receptors (RARα, RARβ and RARγ). These are nuclear receptors that change gene expression and so alter how skin cells grow and mature. The labels state that it has not been established whether the clinical effects come from receptor activation, from irritation, or both (Altreno label).
- In acne: tretinoin makes the cells lining the hair follicle less sticky, so fewer microcomedones (the first, invisible stage of a blackhead or whitehead) form. It also speeds up the turnover of these cells, which pushes existing comedones out (Retin-A label).
- In sun-damaged skin: in human skin exposed to UVB light, tretinoin applied beforehand substantially reduced the induction of collagen-degrading enzymes (matrix metalloproteinases) and of the transcription factor AP-1 that switches them on (Fisher et al., Nature 1996). In a 10–12 month trial, 0.1% tretinoin cream raised collagen I formation in photodamaged forearm skin by 80%, versus a 14% fall with vehicle (p = 0.006) (Griffiths et al., NEJM 1993).
Tretinoin’s labeled mechanism involves follicle and skin cells, not hormones. Clascoterone (Winlevi) is the topical drug on this site that blocks androgen receptors in the skin.
How it works in the body
Only a small fraction of a topical dose reaches the bloodstream:
| Study (label) | Product and conditions | Result |
|---|---|---|
| Retin-A Micro | 500 mg of 0.1% gel daily for up to 28 days, 44 healthy adults, radiolabeled drug | Bioavailability 0.82% after one dose and 1.41% after repeated doses; plasma tretinoin and metabolites about 1–3 ng/mL, essentially unchanged from baseline |
| Renova | Various topical formulations | 1–31% of the applied dose absorbed, higher on dermatitic than healthy skin |
| Renova | 0.05% emollient cream, 7 healthy men single dose and 7 for 28 days | Under 2% absorbed; no significant change in natural tretinoin levels |
| Altreno | About 3.5 g of 0.05% lotion on face, neck, chest, back and shoulders daily for 14 days, 20 adolescents with acne | Mean peak tretinoin 0.33 ng/mL above baseline; steady state by day 14 |
Sources: Retin-A Micro label, Renova label, Altreno label.
In the Altreno maximal-use study, the metabolites isotretinoin and 4-oxo-isotretinoin built up more than tretinoin itself (mean accumulation ratios of 4.5 and 7.3, versus 1.5 for tretinoin). The topical labels do not report a half-life. For oral tretinoin, the capsule label gives a terminal half-life of 0.5–2 hours after the first dose in leukemia patients, with metabolism by liver enzymes CYP3A4, CYP2C8 and CYP2E (tretinoin capsules label).
Approved medical use
US products
| Product | Form and strengths | Labeled indication | Original approval |
|---|---|---|---|
| Retin-A | Cream 0.025%, 0.05%, 0.1%; gel 0.01%, 0.025% | Acne vulgaris | 1971 (solution); cream 1973 |
| Retin-A Micro | Microsphere gel 0.04%, 0.06%, 0.08%, 0.1% | Acne vulgaris, age 12 and older | February 7, 1997 |
| Renova | Cream 0.02% | Add-on for fine facial wrinkles, with sun avoidance and skin care | August 31, 2000 (0.02%) |
| Altreno | Lotion 0.05% | Acne vulgaris, age 9 and older | August 23, 2018 |
| Tretinoin capsules (formerly Vesanoid) | 10 mg oral capsule | Acute promyelocytic leukemia | November 22, 1995 (Vesanoid) |
Sources: product labels above; approval dates from Drugs@FDA. Generic tretinoin creams and gels from many manufacturers, and fixed combinations with clindamycin or benzoyl peroxide, are also listed on DailyMed.
Labeled directions (topical)
- Acne (Retin-A): apply once a day before bedtime, lightly covering the affected area. Results may appear after 2–3 weeks, but more than 6 weeks may be needed before definite benefit (Retin-A label).
- Fine wrinkles (Renova): apply a small pearl-sized amount (about 5 mm across) to the face once in the evening. Up to 6 months may be needed before effects are seen, and some patients lose the benefit after stopping (Renova label).
- More is not better: every label states that applying more, or more often, does not give faster or better results and causes more redness, peeling and discomfort.
What the research shows
Acne
The 2024 AAD acne guideline makes a strong recommendation for topical retinoids, alongside benzoyl peroxide, topical antibiotics and oral doxycycline. Oral isotretinoin is reserved for acne that is severe, scarring, causing psychosocial burden, or failing standard therapy (Reynolds et al., JAAD 2024).
The largest tretinoin trials are the two Altreno studies: randomized, double-blind, vehicle-controlled, 1,640 patients aged 9 and older with moderate to severe acne, 12 weeks (Altreno label):
| Week 12 outcome | Trial 1: tretinoin 0.05% (n = 406) | Trial 1: vehicle (n = 414) | Trial 2: tretinoin 0.05% (n = 413) | Trial 2: vehicle (n = 407) |
|---|---|---|---|---|
| Clear or almost clear, plus 2-grade improvement | 16.5% | 6.9% | 19.8% | 12.5% |
| Non-inflammatory lesions (comedones), mean % reduction | 47.5% | 27.3% | 45.6% | 31.9% |
| Inflammatory lesions, mean % reduction | 50.9% | 40.4% | 53.4% | 41.5% |
Retin-A Micro 0.1% gel was compared with vehicle in two 12-week trials of about 70 patients per arm. Total lesion counts fell by 45% vs 23% in Study 1 and by 32% vs 16% in Study 2 (Retin-A Micro label). The vehicle arms show a pattern common to acne trials: a good share of the improvement happens without the active drug.
Head-to-head and network data:
- Against adapalene: a meta-analysis of 5 randomized, investigator-blinded trials (900 patients) found adapalene 0.1% gel as effective as tretinoin 0.025% gel for total lesions, with better tolerability at every visit (Cunliffe et al., Br J Dermatol 1998). See the adapalene page for the other comparison trials.
- Across topical agents: a network meta-analysis of 35 randomized trials (33,472 participants) found that all single topical agents except tazarotene beat placebo, with no significant difference among most single agents. Clindamycin plus tretinoin was among the most effective combinations, but did not significantly beat tretinoin alone for non-inflammatory lesions (Kakpovbia et al., JEADV 2025).
- Against clascoterone: a small 8-week pilot trial in 77 men found clascoterone 1% cream better than placebo and described it as clinically more effective than tretinoin 0.05% cream (Trifu et al., Br J Dermatol 2011). The trial was too small to settle the comparison.
Acne linked to anabolic steroid use
We searched PubMed and found no clinical trial testing tretinoin specifically in acne linked to anabolic steroid or testosterone use. Tretinoin targets follicle plugging, not the hormonal driver. The AAD guideline’s strong recommendation for oral isotretinoin applies to acne that is severe, scarring or not responding to standard therapy, whatever the cause (Reynolds et al., JAAD 2024).
Fine wrinkles and sun damage (photoaging)
Modern interest began with small trials from the 1980s. In a 16-week double-blind study, all 30 completers improved on the tretinoin-treated forearm, and 14 of 15 patients using tretinoin on the face improved, versus none on vehicle (Weiss et al., JAMA 1988). Larger trials followed:
| Trial | Design | Main result |
|---|---|---|
| Olsen et al., JAAD 1992 | 296 patients, 24 weeks; 0.05%, 0.01%, 0.001% emollient cream vs vehicle | 0.05%: 68% improved vs 43% on vehicle; excellent or good response 26% vs 11%. The 0.01% and 0.001% strengths did not differ from vehicle |
| Renova 0.02% (5 pooled trials, label) | 324 tretinoin vs 332 vehicle patients, 24 weeks | Fine wrinkles, lightly pigmented skin: moderate improvement 10% vs 3%, mild 15% vs 9%, no change 40% vs 58%. Only 2 of 5 trials adequately showed benefit |
| Renova 0.02% (label) | 107 patients with darker skin (types IV–VI) | Minimal or mild improvement in 29% on tretinoin vs 43% on vehicle |
| Kang et al., Am J Clin Dermatol 2005 | 204 patients, 0.05% emollient cream vs vehicle, up to 2 years | Greater improvement in fine and coarse wrinkling, mottled pigmentation, lentigines and sallowness (p under 0.05); no increase in skin-cell atypia on biopsy |
The Renova label is unusually blunt. It states that Renova 0.02% does not eliminate wrinkles, repair sun-damaged skin or reverse photoaging. It did not show benefit for coarse or deep wrinkles, roughness, mottled pigmentation, laxity or other major signs of sun damage, and many vehicle patients improved with sun protection and moisturizers alone (Renova label). The 2-year 0.05% trial reported broader effects, but used a higher strength and a longer duration.
Side effects and risks
Skin irritation (retinoid dermatitis)
Irritation is the main problem with tretinoin. It typically peaks in the first 2 weeks and then eases (Retin-A Micro label).
| Product and trial | Finding |
|---|---|
| Renova 0.02%, 339 patients | Almost all had peeling, dryness, burning, stinging, redness or itching. 32% had irritation that was severe, led to a pause, or needed a mild steroid cream; 7% needed a steroid cream (vs under 1% on vehicle); about 4% stopped |
| Retin-A Micro 0.1% | No more than 3% had severe irritation scores; 6% (14 of 224) stopped because of irritation, 4 of them after 3–5 days, one with blistering |
| Altreno 0.05% (n = 760 vs 782 on vehicle) | Scaling 49% vs 30%; burning 30% vs 14%; stinging 21% vs 8%; erythema 51% vs 44% |
Sources: Renova label, Retin-A Micro label, Altreno label.
Other labeled skin effects and precautions:
- Early flare of acne: an apparent worsening of inflammatory lesions in the first weeks is described in the labels and is not by itself a reason to stop.
- Pigment changes: temporary lightening or darkening of treated skin has been reported.
- Eczema: tretinoin can cause severe irritation on eczematous skin.
- Irritating products: medicated or abrasive cleansers, strongly drying products, high-alcohol products, and acne products with benzoyl peroxide, sulfur, resorcinol or salicylic acid can add to irritation. Wind and cold can too.
- Fish allergy: Altreno contains soluble fish proteins.
- Flammable gels: Retin-A gel is alcohol-based and flammable.
Sun sensitivity
All topical tretinoin labels warn of increased sunburn risk. Patients with sunburn should not use it until recovered, and sunscreen and protective clothing are advised when sun exposure cannot be avoided. Renova should not be used with drugs that also cause photosensitivity, such as thiazide diuretics, tetracyclines, fluoroquinolones, phenothiazines and sulfonamides (Renova label).
In mice, tretinoin enhanced skin tumors caused by high doses of UV light from a solar simulator. The labels state that the significance of this for people is not clear (Retin-A label). Renova also notes atypical skin-cell changes and increased elastosis in some patients using the older 0.05% cream for longer than 48 weeks, of unknown significance; daily use beyond 52 weeks has not been established as safe and effective.
Pregnancy and breastfeeding
Oral isotretinoin causes severe birth defects in humans (Accutane label), and oral tretinoin is teratogenic in rats, mice, hamsters and monkeys (Retin-A label). For topical tretinoin, the evidence is reassuring but limited:
| Study | Design | Result |
|---|---|---|
| Jick et al., Lancet 1993 | 215 first-trimester exposures vs 430 unexposed | Major anomalies 1.9% vs 2.6%; relative risk 0.7 (95% CI 0.2–2.3) |
| Loureiro et al., Am J Med Genet A 2005 | 106 exposed vs 389 unexposed, prospective | Miscarriage 6.6% vs 8.5%; major defects 2.2% vs 1.2%; retinoid-type minor malformations 12.9% vs 9.9% (none significant) |
| Kaplan et al., Br J Dermatol 2015 | Meta-analysis, 654 exposed vs 1,375 unexposed (topical retinoids) | Major malformations OR 1.22 (95% CI 0.65–2.29); miscarriage OR 1.02 (95% CI 0.64–1.63) |
The meta-analysis authors note that these numbers can reassure women exposed by accident, but the studies lack the power to justify deliberate use in pregnancy. The labels also differ on how strongly they phrase it:
- The Retin-A label cites 30 spontaneous reports of birth defects over two decades, 5 of them holoprosencephaly (a rare forebrain defect), with no causal link established. It advises use in pregnancy only if benefit justifies risk (Retin-A label).
- The Renova label says it should not be used during pregnancy or by women trying to become pregnant (Renova label).
- The newer Altreno and Retin-A Micro labels say published observational studies have not established a drug-associated risk, while noting that absorption may result in fetal exposure.
It is not known whether topical tretinoin passes into breast milk.
Oral tretinoin for leukemia (a different product)
Oral tretinoin capsules (formerly Vesanoid) treat acute promyelocytic leukemia at 22.5 mg/m² twice daily, given until remission. This is a far larger systemic dose than any skin product delivers. The capsule label carries a boxed warning for two risks (tretinoin capsules label):
- Embryo-fetal toxicity: a negative pregnancy test is required before starting, with two effective contraceptive methods during treatment and for 1 month after.
- Differentiation syndrome: a potentially fatal reaction that occurred in about 26% of APL patients.
None of this oral-capsule data should be read as applying to topical use, and the topical products should never be taken by mouth. The topical labels note that swallowing them may cause the same effects as excess vitamin A intake.
Who should not use it
- People with hypersensitivity to any ingredient (and, for Altreno, caution with fish allergy).
- Sunburned skin, eczema-affected skin, or broken skin.
- During pregnancy or when trying to conceive, for Renova per its label; for the acne products, use in pregnancy is a decision for the prescriber.
- With photosensitizing drugs, for Renova per its label.
Key takeaways
- Tretinoin is not isotretinoin. Topical tretinoin (all-trans retinoic acid) is a skin product for acne and fine wrinkles; isotretinoin (13-cis retinoic acid, Accutane) is an oral drug for severe acne with far greater systemic risks.
- A first-line acne treatment with modest effect sizes. In the largest trials, about 17–20% of patients reached clear or almost clear skin at 12 weeks, versus 7–13% on vehicle; the AAD strongly recommends topical retinoids.
- Wrinkle benefits are real but limited. Renova 0.02% helps fine wrinkles in some patients; its label states it does not reverse photoaging or treat deep wrinkles.
- Irritation is the main side effect. Peeling, dryness and burning are near-universal early on and peak in the first 2 weeks; about 4–6% of trial patients stopped because of it.
- Sun protection matters. Tretinoin increases sunburn risk, and in mice it enhanced UV-induced skin tumors.
- Pregnancy data are reassuring but not conclusive. Cohort studies and a meta-analysis found no clear increase in birth defects after topical use, but labels advise caution and Renova says not to use it in pregnancy.
Sources
- Bausch Health US. Retin-A (tretinoin) cream and gel prescribing information. Revised 03/2024. DailyMed.
- Bausch Health US. Renova (tretinoin cream) 0.02% prescribing information. DailyMed.
- Bausch Health US. Retin-A Micro (tretinoin) gel microsphere prescribing information. Revised 09/2025. DailyMed.
- Bausch Health US. Altreno (tretinoin) lotion 0.05% prescribing information. DailyMed.
- Par Health USA. Tretinoin capsules prescribing information. Revised 03/2026. DailyMed.
- JG Pharma. Accutane (isotretinoin) capsules prescribing information. Revised 09/2022. DailyMed.
- US Food and Drug Administration. Drugs@FDA: Retin-A, NDA 016921 (and NDA 017340, 020475, 021108, 209353, 020438 for Retin-A cream, Retin-A Micro, Renova 0.02%, Altreno and Vesanoid). FDA.
- National Library of Medicine. DailyMed search results: tretinoin. DailyMed.
- National Center for Biotechnology Information. Tretinoin, PubChem CID 444795. PubChem.
- Reynolds RV, Yeung H, Cheng CE, et al. Guidelines of care for the management of acne vulgaris. J Am Acad Dermatol. 2024;90(5):1006.e1–1006.e30. PubMed.
- Kakpovbia EE, Young T, Milam EC, et al. Efficacy of topical treatments for mild-to-moderate acne: a systematic review and meta-analysis of randomized control trials. J Eur Acad Dermatol Venereol. 2025;39(4):775–784. PubMed.
- Cunliffe WJ, Poncet M, Loesche C, et al. A comparison of the efficacy and tolerability of adapalene 0.1% gel versus tretinoin 0.025% gel in patients with acne vulgaris: a meta-analysis of five randomized trials. Br J Dermatol. 1998;139(Suppl 52):48–56. PubMed.
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- Jick SS, Terris BZ, Jick H. First trimester topical tretinoin and congenital disorders. Lancet. 1993;341(8854):1181–1182. PubMed.
- Loureiro KD, Kao KK, Jones KL, et al. Minor malformations characteristic of the retinoic acid embryopathy and other birth outcomes in children of women exposed to topical tretinoin during early pregnancy. Am J Med Genet A. 2005;136(2):117–121. PubMed.
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- World Anti-Doping Agency. The 2026 Prohibited List. In effect from January 1, 2026. WADA 2026 Prohibited List.