Longevity Lab ReportBeta
← All supplements

Supplement

NAC

The glutathione precursor hospitals actually use.

N-acetylcysteine (NAC) replenishes glutathione, the body's master antioxidant. We grade NAC B- on evidence and B for worth-it at about $12-18 per month.

B-

Evidence

B

Worth it

Typical cost: $12-18/month

What it does

N-acetylcysteine (NAC) replenishes glutathione, the body's master antioxidant. It is an approved drug for acetaminophen overdose and a mucolytic, which gives it a deeper evidence base than most supplements.

What the research says

  • Replenishes glutathione

    Evidence: moderate. Well demonstrated pharmacologically; clinical benefit depends on context.

  • May support respiratory health

    Evidence: emerging. Used as a mucolytic; chronic bronchitis data is mixed.

DRAFT: real pharmacology with a drug-grade safety record; wellness claims outrun the data.

What the experts say

Every position links to its source. We include skeptics alongside supporters.

  • Rhonda Patrick

    “perhaps transiently using N-acetylcysteine may help... a couple times a week versus every day. That would be, I think, my approach.”

    Source Cautious about daily NAC or glutathione supplementation; warns of reductive stress and prefers intermittent use (a couple of times a week).

  • Bryan Johnson

    Source, 2026-03-24 Takes 1,800 mg of NAC daily as a glutathione precursor to reduce cellular stress and support brain and immune function.

Is it worth it?

B

DRAFT: cheap with genuine pharmacology behind it.

Typical cost

$12-18/month

Common form, not a brand recommendation

Dosage contextemerging

600 to 1,200 mg per day in most trials.

Safety notes

Generally well tolerated; high doses can cause nausea. Regulatory status for supplements has shifted in some countries. Talk to your doctor. This page is information, not medical advice.

Longevity Lab Report

NAC news, graded when it happens.

New studies, dose debates, and expert shifts on nac, in one email a week. Free.

Changelog

Last updated 2026-10-15

  • 2026-10-15|Batch 1 expansion entry, DRAFT. Grades provisional; expert positions unsourced unless noted.
  • 2026-10-15|Goals/dosage added; prescription flag set where applicable.