Ashwagandha for Hypothyroidism
Verdict: Published with Warning
Across 4 PubMed studies, the evidence for Ashwagandha in Hypothyroidism grades Tier C — weak evidence. Effective, but with safety or population caveats.
C 🟠 C Weak Evidence Published with Warning
Why this grade7-layer evidence engine
⚖️
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditableRaw score 0.54
D
C
B
A
S
← counter-evidence / ineffectiveeffective / strong evidence →
Final grade
C · Published with Warning
Confidence
76%
Broadly consistent
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 = 0.537
- 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
PubMed studies (4)L2 · primary research & systematic reviews
Achievements in Hypothyroidism Treatment with Herbal Medicine: A Systematic Review of Randomized Controlled Trials
Finding: Across 771 screened articles only 4 RCTs (186 participants total) qualified; the single ashwagandha RCT showed T3 +41.5% (p<0.001), T4 +19.6% (p<0.001) and TSH significantly reduced (p<0.001) at 8 weeks, but the review concluded the evidence base is small and 'more extensive and advanced methodology' is needed.
View on PubMed Safety and clinical effectiveness of Withania Somnifera (Linn.) Dunal root in human ailments
Finding: Of 30 human trials reviewed, only ONE addressed subclinical hypothyroidism; root preparations were judged 'reasonably effective' and safe with only mild transient adverse events, but the authors explicitly call for large, properly-designed RCTs to confirm efficacy.
View on PubMed Efficacy and Safety of Ashwagandha Root Extract in Subclinical Hypothyroid Patients: A Double-Blind, Randomized Placebo-Controlled Trial
Finding: In 50 subclinical hypothyroid adults (TSH 4.5-10 uIU/L), 600 mg/day ashwagandha root extract for 8 weeks significantly improved TSH (p<0.001), T3 (p=0.0031) and T4 (p=0.0096) vs placebo, normalizing thyroid indices.
View on PubMed Subtle changes in thyroid indices during a placebo-controlled study of an extract of Withania somnifera in persons with bipolar disorder
Finding: Thyroid was a secondary safety analysis of a bipolar-cognition RCT; only 10/60 had abnormal indices and arms were unequal (ASW n=3 vs placebo n=7), but all 3 ashwagandha patients showed T4 rises (7%, 12%, 24%), suggesting ashwagandha raises thyroxine and warrants hyperthyroidism vigilance.
View on PubMed Regulatory & authoritative positionsL4/L5 · FDA / EMA / NIH ODS / Cochrane / Mayo …
L4a US FDA
Cautious
WITHANIA SOMNIFERA ROOT source↗
L4d TW TFDA / 衛福部
Cautious
南非醉茄萃取物 source↗
L4e WHO
Neutral
WHO monographs on selected medicinal plants source↗
L5a NIH Office of Dietary Supplements
Cautious
ashwagandha extracts may lower stress, anxiety, and cortisol levels source↗
L5b Mayo Clinic
Cautious
Generally speaking, ashwagandha is safe for most people though some get headaches and nausea. Talk to your healthcare team before starting any supplement to ensure there are no interactions with other medications or conditions, especially if you have autoimmune conditions. source↗
L5c Cleveland Clinic
Against
In addition, ashwagandha can increase thyroid activity. So, it shouldn't be used if you have borderline thyroid or hyperthyroidism. [Avoid ashwagandha if you] have a thyroid condition, like hyperthyroidism (overactive thyroid), hypothyroidism (underactive thyroid) or borderline thyroid. source↗
L5e Specialty Society (condition-mapped)
Cautious
The majority of dietary thyroid supplements tested contained clinically significant amounts of thyroid hormones, and the use of these supplements could potentially increase thyroid function tests and thyrotoxicosis along with its risks for clinical symptoms, arrhythmias and bone loss. source↗