Longevity & Cellular Health; Cognitive & Neuroprotection
N-Acetylcysteine (NAC)
N-acetylcysteine, usually written NAC, is a modified form of the amino acid cysteine and one of the few compounds here with a settled, life-saving use: it is the antidote for paracetamol overdose, and it thins mucus in chronic lung disease by cutting the disulfide bonds that hold mucus together. Its longevity reputation comes from one step further along the same chemistry, since cysteine is the rate-limiting ingredient for making glutathione, the cell's main antioxidant. Where that reasoning has been tested it did not hold: PANTHER-IPF randomised 264 people with pulmonary fibrosis and lung function declined identically on NAC and on placebo, while a third arm combining it with two other drugs was stopped early in 2011 for excess deaths and hospitalisations.
Last updated
Mechanism
Supplies cysteine for glutathione synthesis, scavenges reactive oxygen species directly, and cleaves disulfide bonds in mucus glycoproteins.
Reported effects
What sources associate with this compound. Reported categories, not outcomes we have graded — each would need its own citation and rung.
- Paracetamol overdose antidote
- Mucolytic use in COPD
- Oxidative stress research
Dosing on file unverified
Oral: 600-2,400 mg/day; IV: load 150 mg/kg then 15 mg/kg/h; Oral: 600-2,400 mg/day (600 mg 1-4x daily); Acetaminophen: oral load 140 mg/kg then 70 mg/kg q4h
Carried from a source that labels it unverified, and reproduced with that label attached. A record of what is reported, not a recommendation. No citation on this page establishes it.
Half-life, storage & sport
- Elimination half-life
- approximately 8 h (human, IV) — study. Poultry science 2025; humans; figure restated in this paper’s introduction from Sun et al. 2023, no cohort described.
The half-life on file is 8 h, measured intravenously. At the fastest schedule this record states — every 6 h — each dose is still at 59% of its own peak when the next is given, so the doses overlap: the peaks build to 2.47× the first. The record gives 7 to 28 times a week; the fastest is drawn.
The rise is not modelled and the axis is not a blood level. No absorption rate constant and no volume of distribution are on file, so each dose appears at full height the instant it is given, and the axis is percent of this compound's own peak.
Literature on file 10
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review or editorial
Bromelain and N-acetylcysteine (BromAc) as novel adjunctive therapy for prosthetic joint infection: a narrative review. graded on: indexed as "Review" - secondary literature, not a study — “Review”
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review or editorial
Beyond antioxidant activity, toward redox modulation: N-acetylcysteine (NAC) in endometriosis and uterine leiomyomas. graded on: indexed as "Review" - secondary literature, not a study — “Review”
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human observational
The efficacy of N-acetylcysteine in the management of chronic obstructive pulmonary disease: a systematic review and meta-analysis. graded on: a synthesis of human studies — “systematic review”
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human observational
Therapeutic effect of N-acetylcysteine in severe or critical coronavirus disease 2019 pneumonia: A retrospective cohort study. graded on: an observational human design — “retrospective”
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in vitro
From antioxidant to senotherapeutic: Repurposing n-acetylcysteine to counteract senescence via the HuR pathway in human endothelial cells. graded on: an in-vitro system — read from the indexed abstract — “in vitro”
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human observational
NCT03252925: A Safety and Efficacy Study of N-acetylcysteine in Patients With Transplant-Associated Thrombotic Microangiopathy graded on: a registered clinical study — “clinicaltrials.gov”
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human observational
NCT01501110: Evaluation of the Effects of N-acetylcysteine on Thyroid Hormone Levels in the Low T3 Syndrome graded on: a registered clinical study — “clinicaltrials.gov”
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human observational
NCT00542750: An Open-Label Trial of N-Acetylcysteine in Cannabis Dependent Adolescents graded on: a registered clinical study — “clinicaltrials.gov”
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human observational
NCT00552786: Antioxidation Medication for Noise-induced Hearing Loss graded on: a registered clinical study — “clinicaltrials.gov”
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human observational
NCT00724594: Safety of N-acetylcysteine in Maternal Chorioamnionitis graded on: a registered clinical study — “clinicaltrials.gov”
Identity
Skeletal formulathe canonical depiction
Drawn by PubChem from CID 12035, the identifier on this record.
- Molecular weight
- 163.20
- Molecular formula
- C5H9NO3S
- CAS number
- 616-91-1
- PubChem CID
- 12035
- ChEMBL
- CHEMBL600
- InChI key
- PWKSKIMOESPYIA-BYPYZUCNSA-N
- SMILES
- CC(=O)N[C@@H](CS)C(=O)O
- InChI
- InChI=1S/C5H9NO3S/c1-3(7)6-4(2-10)5(8)9/h4,10H,2H2,1H3,(H,6,7)(H,8,9)/t4-/m0/s1
Also called
- N-Acetylcysteine (NAC) (Longevity)
Notes unverified prose
Numerous RCTs; standard clinical use; Standard oral anti-inflammatory: 600 mg 1-2x/day; IV NAC 50 mg/kg weekly + oral 500 mg BID
Not on file 1
1 of the 8 fields we track hold nothing on this record, and each says why. A blank field is a bug; a named absence is a finding.
- amino-acid sequencenot applicable to this compound
Each field links to every other record missing the same thing. The full ledger holds 765 gaps across 163 records.
Listed prices 2
What 1 shop we track listed for N-Acetylcysteine (NAC), read from their own public catalogues on 2026-09-14. We take no commission on these and they are not ranked by any payment — how vendors are scored.
Compare prices2 listings from 1 shop
| Vendor | Size | Price | Per mg |
|---|---|---|---|
| PureRawz ships worldwide | size not listed | $42.07 USD | — |
| PureRawz ships worldwide | size not listed | $87.99 USD | — |
None of these shops lists your destination. Choose “Show all” to see every listing we hold.
Prices are the vendor's own listing, reproduced with the date we read it — never converted between currencies, and compared per milligram only where the vendor states the vial size.
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