Azelaic Acid for Acne
Topical azelaic acid is an evidence-backed treatment for mild-to-moderate acne, reliably reducing inflammatory lesions; it works about as well as topical retinoids and slightly less well than benzoyl peroxide, so it is often used as a well-tolerated alternative or add-on.
Why this grade7-layer evidence engine
This earns a moderate-evidence (Tier A) grade because regulators and high-quality trials line up cleanly. The US FDA approves azelaic acid 20% cream (Azelex) for mild-to-moderate inflammatory acne vulgaris, the UK's NHS/NICE lists it as a treatment option for acne, and NIH MedlinePlus confirms its use for acne; EFSA is neutral only because azelaic acid is a topical medicine, not a food, and the WHO entry was not found.
The clinical data are consistent. A 2023 systematic review (PMID 37550898; 43 trials spanning acne, rosacea, melasma and skin aging) found azelaic acid more effective than vehicle for acne, and a double-blind RCT showed a 60.6% lesion reduction versus 19.9% for placebo (PMID 17456913). An older comparative trial confirmed efficacy for papulopustular acne (PMID 2528258).
What keeps this at moderate rather than top tier is its relative potency. An abridged Cochrane review (49 RCTs, 3,880 people; PMID 33034949) found azelaic acid roughly equal to tretinoin but probably less effective than benzoyl peroxide, while a trial of azelaic acid combined with glycolic acid versus tretinoin showed comparable improvement with less irritation (PMID 9737831). It also fades acne-related dark marks (PMID 37213446), making it a well-tolerated combination or alternative agent. Higher strengths are prescription-only; over-the-counter cosmetic versions are weaker.
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditable▸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 = 0.785
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 positive (1 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