Lavender for Anxiety
A standardized oral lavender oil preparation (Silexan) is one of the better-evidenced herbal options for anxiety, with several randomized trials and two meta-analyses showing a real benefit. That evidence does not transfer to lavender tea, ordinary capsules, or aromatherapy, and most of the key trials were industry-funded, so the overall grade is preliminary rather than strong.
Why this grade7-layer evidence engine
The grade rests on consistent randomized data for one specific product. A double-blind trial in generalized anxiety disorder (PMID 24456909, n=539) found 80 and 160 mg/day of Silexan reduced HAM-A anxiety scores significantly more than placebo, with the higher dose comparable to paroxetine. A smaller trial (PMID 19962288, n=77) showed it was about as effective as lorazepam, and a third (PMID 20512042, n=221) beat placebo in subsyndromal anxiety. Two meta-analyses (PMID 27861196; PMID 31792285) pooled these results and confirmed a significant effect.
It falls short of a top grade for two reasons. Almost all the pivotal trials were funded by the manufacturer, and NIH's Office of Dietary Supplements calls the evidence 'promising but limited' by sample sizes and funding. Crucially, the benefit is tied to the standardized oral oil, not to lavender tea, generic capsules, or inhaled aromatherapy, which were not what these trials tested.
Regulators and clinicians are mixed. The FDA recognizes lavender oil only as a safe flavoring, has not approved any anxiety claim, and has warned companies marketing it as a treatment; Cleveland Clinic notes its linalool component may ease anxiety but stays cautious. Lavender oil can also add to the sedative effect of benzodiazepines, alcohol, and similar drugs.
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 = 0.622
- 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 + 1 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status