Tretinoin (Topical) for Acne
Verdict: Published
Across 5 PubMed studies, the evidence for Tretinoin (Topical) in Acne grades Tier A — moderate evidence.
A 🔵 A Moderate Evidence Published
Why this grade7-layer evidence engine
⚖️
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditableRaw score 0.76
D
C
B
A
S
← counter-evidence / ineffectiveeffective / strong evidence →
Final grade
A · Published
Confidence
90%
Highly consistent evidence
Evidence level
E2
Multiple high-quality MAs (≥2 independent, consistent)
▸View the full decision path (audit trail)
- compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.76
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 positive (2 篇 > 0 negative)
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 0 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status
PubMed studies (5)L2 · primary research & systematic reviews
Comparative Efficacy of Pharmacological Treatments for Acne Vulgaris: A Network Meta-Analysis of 221 Randomized Controlled Trials
Finding: Topical retinoid monotherapy was only comparable to oral/topical antibiotics for inflammatory lesions; the best-ranked regimens were oral isotretinoin (MD=48.41) and topical-retinoid-containing triple therapy (retinoid+antibiotic+BPO, MD=38.15), i.e. tretinoin is most effective in combination rather than alone.
View on PubMed A systematic review and network meta-analysis of topical pharmacological, oral pharmacological, physical and combined treatments for acne vulgaris (NICE NG198)
Finding: Across 179 RCTs (~35,000 observations), retinoid-containing combinations were among the most effective (retinoid+BPO 26.2% improvement for mild-to-moderate; retinoid+clindamycin 44.4% for moderate-to-severe); tretinoin was not analysed as a standalone agent and topical retinoids were less well tolerated than placebo.
View on PubMed Comparative Efficacy of Pharmacological and Nonpharmacological Interventions for Acne Vulgaris: A Network Meta-Analysis
Finding: Across 73 RCTs (27,745 patients), topical-retinoid-containing combinations ranked highest for noninflammatory lesions (TR+BPO MD=-21.89, 95%CrI -28.97 to -14.76, SUCRA 94%), confirming tretinoin-class efficacy is greatest when combined with benzoyl peroxide rather than as monotherapy.
View on PubMed Novel Tretinoin 0.05% Lotion for the Once-Daily Treatment of Moderate-to-Severe Acne Vulgaris: Assessment of Efficacy and Safety in Patients Aged 9 Years and Older
Finding: In two pooled pivotal phase-3 vehicle-controlled trials (N=1640), tretinoin 0.05% lotion monotherapy cut inflammatory lesions 52% and noninflammatory lesions 46% at 12 weeks (both P<0.001 vs vehicle), but 2-grade EGSS 'clear/almost clear' success reached only 18%.
View on PubMed A combined analysis of 2 randomized clinical studies of tretinoin gel 0.05% for the treatment of acne
Finding: In two pooled phase-3 trials (N=1537), tretinoin gel 0.05% was superior to vehicle for inflammatory and noninflammatory lesion reduction and treatment success (all P<0.001), though it was ~12% less effective than tretinoin microsphere 0.1% (while causing fewer skin AEs, 31% vs 52%).
View on PubMed Regulatory & authoritative positionsL4/L5 · FDA / EMA / NIH ODS / Cochrane / Mayo …
L4a US FDA
Supportive
RETIN-A (tretinoin) is indicated for topical application in the treatment of acne vulgaris. RENOVA (tretinoin cream) 0.05% is indicated as an adjunctive agent for use in the mitigation (palliation) of fine wrinkles, mottled hyperpigmentation, and tactile roughness of facial skin in patients who use comprehensive skin care and sunlight avoidance programs. RENOVA DOES NOT ELIMINATE WRINKLES, REPA… source↗
L4b EU EFSA
Cautious
For topically applied retinoids (adapalene, alitretinoin, isotretinoin, tazarotene and tretinoin), systemic absorption is negligible, and unlikely to result in psychiatric disorders. ... topical retinoids must also not be used during pregnancy, and by women planning to have a baby. source↗
L4c UK NHS
Supportive
Tretinoin and adapalene are topical retinoids used to treat acne. They're available in a gel or cream and are usually applied once a day before you go to bed. Apply to all the parts of your face affected by acne 20 minutes after washing your face. Topical retinoids work by removing dead skin cells from the surface of the skin (exfoliating), which helps prevent them building up within hair folli… source↗
L4d TW TFDA / 衛福部
Supportive
外用A酸藥膏，僅新上市或濃度較高的製劑屬於處方藥，其他多數外用A酸，例如濃度不超過0.1%之Tretinoin，即為指示藥品，民眾可在諮詢藥師或醫師後，自行於藥局購買。衛生福利部食品藥物管理署建議，若是嚴重或大面積痤瘡，應尋求專科醫師診治；而輕度及小面積的痘痘，則可至藥局向藥師諮詢，再購買外用A酸指示藥品。 source↗
L4e WHO
Supportive
It is on the World Health Organization's List of Essential Medicines. [...] the compound received US Food and Drug Administration (FDA) approval for acne in 1971. [...] Use during pregnancy is contraindicated due to the risk of birth defects. [...] Tretinoin activates three members of the retinoic acid nuclear receptors (RARα, RARβ, and RARγ) which may act to modify gene expression, subsequent … source↗
L5a NIH Office of Dietary Supplements
Supportive
Tretinoin is indicated for topical application in the treatment of acne vulgaris. Rx only. HUMAN PRESCRIPTION DRUG LABEL. Tretinoin should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Exposure to sunlight, including sunlamps, should be minimized during the use of tretinoin. The skin of certain sensitive individuals may become excessively red,… source↗
L5b Mayo Clinic
Supportive
Tretinoin is used to treat acne vulgaris or other skin diseases as determined by your doctor. It works partly by keeping skin pores clear. During the first 3 weeks you are using tretinoin, your skin may become irritated, and your acne may seem to get worse before it gets better. It may take longer than 12 weeks before you notice full improvement of your acne, even if you use the medicine every … source↗
L5c Cleveland Clinic
Supportive
TRETINOIN (TRET i noe in) treats acne. It belongs to a group of medications called retinoids. This medication is for external use only. Do not take by mouth. Apply a thin film of the medication to the affected area. Do not apply to burned or damaged skin. This medication can make you more sensitive to the sun. Keep out of the sun. It may be some time before you see the benefit from this medicat… source↗
L5d Harvard Health
Supportive
Topical tretinoin, which works by turning over skin cells faster to prevent clogged pores, is a mainstay in any acne treatment regimen, and has the added bonus of treating fine wrinkles and evening and brightening skin tone. source↗
L5e Specialty Society (condition-mapped)
Supportive
Topical retinoids (e.g. adapalene, tretinoin, tazarotene, trifarotene) to help unclog pores and reduce inflammation. source↗