longevityNAC (N-Acetyl Cysteine)
longevity

NAC (N-Acetyl Cysteine).

4.2
Reviewed by Pierson Riley — Founder, UtritionReviewed under Utrition’s editorial methodologyLast reviewed Jan 2026Allergen-free

A precursor to glutathione, the bodys master antioxidant.

amino-acidantioxidantliverrespiratoryglutathione
Evidence
B
Moderate evidence
Best time
Morning
Can be split throughout day
Typical dose
600–1800
mg
Primary use
Amino Acid
Quick answer

NAC (N-Acetyl Cysteine) in one minute. A precursor to glutathione, the bodys master antioxidant. Typical dose: 600–1800 mg. Take in the morning or afternoon. May enhance effects; do not combine.

What is NAC (N-Acetyl Cysteine)?

NAC is the supplemental form of cysteine, providing the rate-limiting precursor for glutathione synthesis. It has mucolytic properties (thins mucus), supports liver detoxification, and has been studied for mental health applications. Regulatory status has shifted in some markets.

Glutathione support
Respiratory mucus thinning
Liver support

Keep reading

What is NAC (N-Acetyl Cysteine)?

A precursor to glutathione, the bodys master antioxidant.

NAC is the supplemental form of cysteine, providing the rate-limiting precursor for glutathione synthesis. It has mucolytic properties (thins mucus), supports liver detoxification, and has been studied for mental health applications. Regulatory status has shifted in some markets.

What the evidence says

The overall evidence grade for NAC (N-Acetyl Cysteine) is B (moderate — mixed or smaller trials, reasonable mechanistic support). Established glutathione precursor. Multiple therapeutic applications.

Specific findings with supporting evidence:

Best-supported outcomes:

Where marketing outpaces evidence:

Dose and timing

The typical effective dose for NAC (N-Acetyl Cysteine) is 600–1800 mg. Often 600mg 1-3x daily.

Take it in the morning and afternoon. Can be split throughout day.

Who it's for, and who should skip it

Most relevant for:

Not appropriate for:

Safety and cautions

Important: Nitroglycerin. May enhance effects; do not combine. GI effects. Can cause nausea in some people. Regulatory. Status as supplement varies by region.

Common mistakes

Myths vs reality

A common misconception: NAC is the same as glutathione. In reality, nAC is a precursor; the body makes glutathione from it.

How it interacts with other compounds

Questions people ask

NAC vs glutathione supplements? NAC is better absorbed orally and allows the body to regulate glutathione production.

Editorial note

This guide summarizes the published evidence on NAC (N-Acetyl Cysteine). It is educational content, not medical advice. Confirm with your clinician if you take prescription medications or manage a chronic condition.