N-Acetylcysteine (NAC)
An amino-acid derivative and glutathione precursor studied for exercise and antioxidant effects.
Supplements
Research records
Historical source snapshot. Not freshly verified, not a recommendation. Study findings, community accounts and app defaults are not interchangeable.
Publication suitability · 2026-10-15: Historical reference only; not a clinical verification. Clinical, regulatory, efficacy, safety and dose claims are not independently established by this review.
N-Acetylcysteine (NAC)
An amino-acid derivative and glutathione precursor studied for exercise and antioxidant effects.
Evidence category: Systematic review. This describes the source category, not approval or certainty.
Regulatory statement in source: Not separately recorded; do not infer approval from the evidence category.
N-Acetylcysteine is a modified form of the amino acid cysteine and a precursor to glutathione, the body's primary intracellular antioxidant. It is used medically as a mucolytic and as an antidote, and has been studied separately as an oral supplement for antioxidant support, exercise recovery and cognitive effects, with results across these uses remaining mixed.
Benefits reported in the imported source
- Some trials report reduced muscle soreness and lactate levels after exercise
- Well-characterized antioxidant and glutathione-precursor mechanism
- Long history of medical use as a mucolytic supports a known safety profile at studied doses
Risks and limits
- Pooled evidence shows no significant net benefit for exercise performance
- Higher doses are linked with a higher rate of gastrointestinal and other side effects
- Reporting quality is inconsistent across trials, limiting confidence in the pooled results
Source bottom line: The performance-enhancing case for NAC is weak and inconsistent in pooled analysis, and review authors found insufficient evidence to support its use as an ergogenic aid.
Uncertainty: Reference information only. Not medical advice.
Study protocols — reports, not instructions
Trained and recreationally active adults across seven trials included in the sport-performance meta-analysis
- Reported regimen
- Daily oral NAC doses reported across trials ranged from 1.2 g to 20.0 g, with a typical reported dose around 5.8 g per day
- Duration
- Trial durations varied across the seven pooled studies
- Reported outcome
- Pooled analysis found a mean performance increase of 0.29 percent that was not statistically significant, and higher doses were associated with more frequent side effects
- Source
- Performance and Side Effects of Supplementation with N-Acetylcysteine: A Systematic Review and Meta-Analysis - PubMed
Claim provenance
evidence.json#/catalog:supplement:nac/protocols/0
Community and practice descriptions
Accounts of a practice are not evidence of safety or effectiveness. Words such as “standard”, “safe” or “recommended” describe the source account, not verified consensus or this wiki’s advice. Commercial and self-published citations are retained for traceability, not vendor endorsement or independent clinical corroboration.
Historical research outcome: no-verified-description · 2026-10-06
No suitable community description was independently verified in these checks. The entry remains empty; this does not establish that no practice exists elsewhere.
- https://www.fda.gov/food/hfp-constituent-updates/fda-releases-final-guidance-enforcement-discretion-certain-nac-products: no-practice-description — The inspected FDA page explains a regulatory enforcement policy for products, not a reported community routine.
Pharmacokinetic context
Historical half-life estimate: 2.27 hours. Borgstrom et al. 1986, Eur J Clin Pharmacol, PMID 3803419 — oral/IV crossover; oral bioavailability only 6-10%. The FDA's IV label (Acetadote) quotes 5.6 hours over a longer total-acetylcysteine sampling window Population/route context and estimates may differ. This is not a schedule or a verified human dosing rule.
Source references
Snapshot provenance
Source ID: catalog:supplement:nac. Commit: adc7684614f9439b41d91a3312b62e7982c7e20e. Review state: historical-not-reverified. Authored links are retained separately from the canonical evidence links in the public data. App templates/defaults and rejected drafts are archived, not deployed.
Related entries and components
None listed.