N-acetylcysteine (NAC)
An antioxidant and a building block for glutathione, proposed to reduce oxidative stress and improve insulin sensitivity and ovulation (particularly in PCOS) and to support sperm quality.
Also known as N-acetyl cysteine, acetylcysteine.
At a glance
Updated monthly · checked 10 h agoN-acetylcysteine (NAC) is an antioxidant marketed as a fertility supplement. It is not a fertility drug. Its computed evidence score is ~56/100. Biologically plausible with some encouraging small PCOS data, but far from proven; treat it as adjunctive and evidence-limited.
- Randomized trials
- 29
- Systematic reviews
- 63Computed
- Real product labels indexed
- 20 in the NIH DSLD
Marketed as an antioxidant to improve ovulation (often alongside clomiphene in PCOS) and egg or sperm quality.
Biologically plausible with some encouraging small PCOS data, but far from proven; treat it as adjunctive and evidence-limited.
What the evidence says
Computed from the volume and type of primary studies, not the strength of the marketing. Each figure below links to its live search.
Some small PCOS trials suggest it may improve ovulation and metabolic markers, and small andrology studies suggest possible sperm benefits, but the evidence is limited, mixed, and not sufficient to establish it as a proven fertility treatment.
- Oxidative Imbalance in Endometriosis-Related Infertility—The Therapeutic Role of Antioxidants2024 · 31 citations
- N-acetylcysteine supplementation improves endocrine-metabolism profiles and ovulation induction efficacy in polycystic ovary syndrome2024 · 29 citations
- Polyethylene Terephthalate Microplastic Exposure Induced Reproductive Toxicity Through Oxidative Stress and p38 Signaling Pathway Activation in Male Mice2024 · 25 citations
- N-Acetylcysteine Alleviates D-Galactose-Induced Injury of Ovarian Granulosa Cells in Female Rabbits by Regulating the PI3K/Akt/mTOR Signaling Pathway2024 · 21 citations
- Micronutrient antioxidant supplementation alleviates valproic acid-induced oxidative stress and male infertility via the NRF2/HO-1 pathway2025 · 20 citations
Source: europepmc+pubmed+openalex · as of Sep 25, 2026
Real product labels
Actual marketed supplement products indexed by the NIH Dietary Supplement Label Database. A product being on a shelf is not evidence it works.
- NACThorneCapsule
- N-Acetylcysteine (NAC) 600 mgOff marketDCCapsule
- NAC N-Acetylcysteine 600 mgFoster RegalCapsule
- N-Acetylcysteine (NAC) 600 mgWonder LaboratoriesCapsule
- N-Acetylcysteine (NAC) 600 mgWonder LaboratoriesCapsule
- N-Acetylcysteine (NAC) 600 mgWonder LaboratoriesCapsule
- N-Acetylcysteine (NAC) 600 mgDCCapsule
- NACOff marketThorneCapsule
- NAC SAPNFHCapsule
- NAC 880 mgFresh NutritionCapsule
- Cholesterol Regulation ComplexShakleeTablet or Pill
- Vita-Lea Gold Vitamin K FormulaOff marketShakleeTablet or Pill
- N-AcetylcysteineDouglas LaboratoriesTablet or Pill
- N-Acetylcysteine (NAC) 600 mgWonder LaboratoriesCapsule
- N-Acetylcysteine (NAC) 600 mgWonder LaboratoriesCapsule
- Vita-Lea Gold without Vitamin K FormulaShakleeTablet or Pill
- High Potency Vita-Lea Gold With Vitamin KShakleeTablet or Pill
- NACOff marketThorneCapsule
- AntiOxidant FormulaOff marketPure VeganCapsule
- Vita-Lea Gold Without Vitamin KOff marketShakleeTablet or Pill
Source: NIH Dietary Supplement Label Database (DSLD) · as of Sep 30, 2026
What to watch for
Generally well tolerated; GI upset can occur at higher doses. Its regulatory status as a supplement has been contested in the US. Discuss with a clinician.
What it actually is
N-acetylcysteine (NAC) is a single, characterized compound. Its structure, molecular formula, weight, and synonyms are on its PubChem compound record.
Source: PubChem (PUG-REST)