N-Acetylcysteine for PCOS
Verdict: Published with Warning
Across 4 PubMed studies, the evidence for N-Acetylcysteine in PCOS grades Tier B — preliminary evidence. Effective, but with safety or population caveats.
B 🟡 B Preliminary Evidence Published with Warning
Why this grade7-layer evidence engine
⚖️
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditableRaw score 0.63
D
C
B
A
S
← counter-evidence / ineffectiveeffective / strong evidence →
Final grade
B · Published with Warning
Confidence
75%
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 = 0.625
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 positive (3 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
Efficacy of N-Acetylcysteine in Polycystic Ovary Syndrome: Systematic Review and Meta-Analysis
Finding: NAC vs placebo/other drugs: progesterone increased (SMD 0.95, 95% CI 0.13-1.77, p=0.02); endometrial thickness increased (SMD 0.58, 95% CI 0.10-1.06, p=0.02); NAC vs metformin: LH reduced (SMD 0.67, 95% CI 0.23-1.12, p=0.003). No significant differences in estradiol, SHBG, FSH.
View on PubMed The effects of N-acetylcysteine supplement on metabolic parameters in women with polycystic ovary syndrome: a systematic review and meta-analysis
Finding: NAC vs metformin: FBG reduced (SMD -0.23, 95% CI -0.43 to -0.04, p=0.02); fasting insulin non-significant (SMD -0.24, 95% CI -0.53 to 0.06, p=0.115); BMI non-significant (SMD -0.16). NAC vs placebo: FBG reduced (SMD -0.54, 95% CI -1.03 to -0.05, p=0.032); total cholesterol reduced (SMD -0.74, 95% CI -1.37 to -0.12, p=0.020).
View on PubMed The effects of N-acetylcysteine on ovulation and sex hormones profile in women with polycystic ovary syndrome: a systematic review and meta-analysis
Finding: NAC vs placebo: total testosterone reduced (SMD -0.25 ng/mL, 95% CI -0.39 to -0.10, p<0.001); FSH increased (SMD 0.39, 95% CI 0.07 to 0.71, p=0.01); estradiol increased after trim-and-fill correction. Non-significant for progesterone, LH, SHBG, follicle count, endometrial thickness. NAC induces ovulation and increases live birth rates.
View on PubMed N-acetylcysteine supplementation improves endocrine-metabolism profiles and ovulation induction efficacy in polycystic ovary syndrome
Finding: Clinical pregnancy rate per cycle higher with NAC (30.99% vs 23.30%, p=0.040); cumulative pregnancy rate per patient higher (77.88% vs 58.04%, p=0.001); lower uFSH dosage and shorter induction duration (p<0.005); LH, testosterone reduced and insulin sensitivity improved (all p<0.05). Ovulation rate per cycle similar (94.37% vs 93.55%, p=0.684).
View on PubMed Regulatory & authoritative positionsL4/L5 · FDA / EMA / NIH ODS / Cochrane / Mayo …
L4a US FDA
Cautious
NAC is excluded from the dietary supplement definition under section 201(ff)(3)(B)(ii) of the Federal Food, Drug, and Cosmetic Act source↗
L4b EU EFSA
Against
a cause and effect relationship has not been established source↗
L4c UK NHS
Supportive
Acetylcysteine is the antidote used to treat paracetamol overdose source↗
L5a NIH Office of Dietary Supplements
Cautious
NAC has FDA approval for treating potentially hepatotoxic doses of acetaminophen. source↗