amino acid · for acne
N-Acetyl Cysteine
Tops up your body’s main antioxidant, which calms the inflammation behind breakouts.
Say that in clinical terms
NAC replenishes glutathione, the master antioxidant that neutralizes reactive oxygen species driving acne inflammation. It also reduces NF-kB-mediated inflammatory signaling, decreases sebum lipid peroxidation, and supports liver detoxification pathways.
How strong is the research?
2 papers read, 2 supporting.
Tested as: topical N-acetylcysteine (compounded skin-applied preparation, not an oral capsule)
Who was studied: No trial population — the cited source is a review article rather than a study.
How much to take
daily
600–1200 mg
NAC supports glutathione production which reduces oxidative stress involved in acne pathogenesis.
Before you take it
- No IOM/NIH ODS Tolerable Upper Intake Level established for NAC as a dietary supplement (not an essential nutrient); adverse effects are dose-dependent and increase above 1,200 mg/day.
- Potentiates organic nitrate drugs (nitroglycerin, isosorbide dinitrate) — severe hypotension documented in cardiology settings; avoid co-administration.
- Additive anticoagulant effect with warfarin (INR monitoring required); additive antiplatelet effect with aspirin.
- Antibiotic separation required: administer NAC at least 2 hours before or 4–6 hours after tetracyclines and quinolones to prevent chelation-mediated reduction in antibiotic absorption.
- GI side effects (nausea, vomiting, diarrhea) are dose-dependent; most common at oral doses above 1,200 mg/day.
- FDA drug-exclusion position (2020): FDA classified NAC as excluded from the dietary supplement definition because it was authorized as a new drug in 1963 (Mucomyst/acetylcysteine). As of 2022, FDA exercised enforcement discretion allowing existing NAC supplements on market; no final rule published as of 2025, leaving US supplement regulatory status unsettled.
- Rare anaphylactoid reactions with IV formulations; bronchospasm with inhaled/nebulized forms; both are uncommon via oral supplementation route.
What we make of it
The source is a review article, not a trial.
The detail
What we cite is a narrative review of NAC across skin conditions rather than an original study. Small open-label acne trials do exist, but open-label without a placebo group is weak ground for a strong rating.