Amino Acid Derivative
N-Acetylcysteine
Also known as: NAC
A precursor to glutathione that supports antioxidant defence, brain health, and mood regulation.
KÖGN Health grades N-Acetylcysteine as A (Strong evidence) and rates it 4.3 out of 5.
Last reviewed · June 2026
Primary effects
- Neuroprotection
- Improved mood
- Reduced oxidative stress
How it works
Boosts glutathione levels, reducing oxidative stress and supporting neurotransmitter balance.
Overview
NAC is widely studied for its role in supporting glutathione, one of the body’s primary antioxidant systems. It has also been explored for its effects on mood regulation and compulsive behaviours through glutamate modulation. Its benefits are more long-term and systemic rather than immediately cognitive, making it a foundational health-support compound.
The evidence
NAC is a precursor to glutathione (the body's main antioxidant) and modulates glutamate signalling. Its strongest evidence is in psychiatry — as an add-on in conditions such as OCD, trichotillomania and bipolar depression — rather than as a focus aid. Direct cognitive-enhancement evidence in healthy people is preliminary; some trials in psychosis report improved working memory, but these need replication.
How to dose it
Psychiatric trials commonly use 600–1,800 mg/day (sometimes up to 2,400 mg), usually split into two doses.
When to take it
Chronic — psychiatric effects build over weeks to months.
Safety & side effects
Generally well tolerated; the usual complaints are nausea and other GI upset. A sulfurous smell is common.
Who should avoid it
Speak to a clinician if you have asthma (rare bronchospasm has been reported), take nitroglycerin (NAC can enhance its effect) or anticoagulants. It is a recognised treatment for paracetamol overdose, which is a medical emergency — not a use for self-supplementation.
References
Related ingredients
Graded entries that target the same cognitive goals.
Categories
Draft — the dose, safety and evidence notes on this entry were prepared from the published literature and are pending editorial and clinical review.
Educational information, not medical advice. The evidence grade is KÖGN’s editorial assessment of published research, not a health claim. Speak to a qualified clinician before changing what you take.