NAC (N-Acetyl Cysteine)
600 mg · Daily
Robert
Founder, F*CK Getting Old — independent researcher, not a medical professional.
Last reviewed · 1 cited source
Evidence
- Human Studies
- 80
- Animal Studies
- 60
- Clinical Status
- Dietary Supplement
- Confidence
- Moderate
- Long-Term Safety
- Well-established at supplement doses; the prescription drug form has decades of use for its approved indications
What this score is: a measure of how much research exists and how far along it is (animal-only vs. human trials, research-stage vs. FDA approved) — not how safe, effective, or worth trying a compound is. A low score usually means “early stage” or “understudied,” not “bad.” A high score doesn’t mean “better” for your goals than a lower-scored one.
This is not my personal rating of the compound, not a recommendation, and not medical advice. It’s a general research synthesis for informational purposes only, not a live literature count. See the linked research and talk to a licensed clinician before making decisions based on it.
Mechanism
N-Acetyl Cysteine is a precursor to glutathione, the body's primary intracellular antioxidant, and to cysteine, an amino acid used in protein synthesis. It is FDA-approved as a prescription drug (Acetadote, Mucomyst) for acetaminophen overdose and chronic mucus conditions; the over-the-counter supplement form at lower doses is studied more for general antioxidant and respiratory support.
Common Protocols
- 600–1200 mg daily, split into 1-2 doses
- Take a couple hours away from other medications if unsure about interactions
Side Effects
- GI upset, nausea
- Sulfur-like smell/taste some people find unpleasant
Interactions
- May enhance the effect of nitroglycerin and other nitrates
- Theoretical interaction with blood thinners given mild antiplatelet effects
Practical Details
- Cost
- $
- Typical Dose
- 600 mg
- Storage
- Store in a cool, dry place
Key Studies & Reviews
- Tenório MCDS et al. (2021). N-acetylcysteine (NAC): impacts on human health. Antioxidants (Basel). PMID 34208683.
Search the Research
NAC (N-Acetyl Cysteine) FAQ
What is the typical NAC (N-Acetyl Cysteine) dosage?
Commonly reported protocols: 600–1200 mg daily, split into 1-2 doses; Take a couple hours away from other medications if unsure about interactions. Our reference entry uses 600 mg, Daily. These reflect protocols reported in research and user communities, not a medical recommendation — dosing should be decided with a clinician.
What are the side effects of NAC (N-Acetyl Cysteine)?
Reported side effects include: GI upset, nausea; Sulfur-like smell/taste some people find unpleasant.
Is NAC (N-Acetyl Cysteine) FDA approved?
NAC (N-Acetyl Cysteine) is sold as a dietary supplement. The FDA does not approve supplements for safety or effectiveness before they are sold, so third-party tested brands are worth seeking out.
How much research is there on NAC (N-Acetyl Cysteine)?
Our evidence profile counts roughly 80 human and 60 animal studies, with moderate overall confidence. Long-term safety: Well-established at supplement doses; the prescription drug form has decades of use for its approved indications.
Does NAC (N-Acetyl Cysteine) interact with other drugs or supplements?
May enhance the effect of nitroglycerin and other nitrates; Theoretical interaction with blood thinners given mild antiplatelet effects.
Related compounds
Glutathione precursor; also FDA-approved as a prescription drug for acetaminophen overdose