Low-Level Laser Therapy (LLLT) for Alopecia Areata
There is not enough reliable human evidence to say that low-level laser therapy (LLLT) helps alopecia areata. No double-blind, sham-controlled trial has tested it for this condition, and major dermatology authorities do not list it as a treatment option.
Why this grade7-layer evidence engine
The grade is Unverified because the human evidence for alopecia areata specifically is thin and uncontrolled. The largest analysis, a 2025 systematic review and meta-analysis (PMID 39404126) pooling 3,098 people, could only meta-analyze androgenetic (pattern) hair loss; just 50 of those patients had alopecia areata, scattered across five small studies the authors deemed statistically insufficient to combine. The remaining sources are a single-patient case report (PMID 37583500) and two narrative reviews (PMID 40878907, PMID 23970445) that cite only case reports, animal models, and anecdote for this condition.
Regulators and clinics do not back this use. The US FDA has cleared LLLT devices (HairMax, Capillus, iRestore and others) only for androgenetic alopecia, not alopecia areata, and EFSA, the NHS and WHO take no position on it for hair loss. Harvard Health, the National Alopecia Areata Foundation and the American Academy of Dermatology omit LLLT entirely from their alopecia areata treatment lists.
Nuance matters here: pattern hair loss and alopecia areata are biologically different, so LLLT's positive AGA data cannot be extrapolated. The 2025 narrative review (PMID 40878907) is industry-funded and even notes that 308 nm excimer laser has more alopecia-areata evidence than 650-680 nm LLLT. Because patchy alopecia areata often regrows on its own (roughly half within a year), uncontrolled reports like the case study cannot rule out spontaneous remission. Established options are corticosteroid injections and FDA-approved JAK inhibitors.
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 = 0.427
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 無高階證據可裁決
- tier_strict_requirement_check — | C→U 因 scope.conflation_risk=true 且 L11 獨評較低 (B7-2 tier cap)
- detect_disputes — 偵測到 0 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status