Head to head
NAC against Glutathione
The precursor and the molecule it makes. NAC is FDA-approved as a mucolytic and as the antidote for paracetamol overdose; oral glutathione has to survive digestion to matter, which is the whole argument for taking the precursor instead.
Column A
NACN-Acetylcysteine
A glutathione precursor that is FDA-approved as a mucolytic and antidote for acetaminophen overdose, and studied more broadly in psychiatry and respiratory health.
Column B
GlutathioneGlutathione (GSH, gamma-glutamyl-cysteinyl-glycine)
The body's master intracellular antioxidant tripeptide, used to support redox balance, detoxification, and skin, with mixed clinical evidence for supplementation.
Side by side, on the facts we can check
| Attribute | NAC | Glutathione |
|---|---|---|
| Category | Antioxidant | Antioxidant |
| FDA status | FDA-approved (mucolytic; acetaminophen overdose antidote); also sold as a supplement | Not an approved drug; sold as a supplement (injectable forms flagged by FDA) |
| Half-life | ~5-6 hours | Minutes (plasma) |
| Molecular weight | 163.2 Da | 307.3 Da |
| Mechanism | Provides cysteine to replenish glutathione, directly scavenges free radicals, and modulates glutamatergic signaling in the brain. | Neutralizes reactive oxygen species directly and via glutathione peroxidase, recycles other antioxidants, and conjugates toxins for elimination through glutathione S-transferases. |
| Human studies cited | 3 | 2 |
| Legal status, US | FDA-approved drug and sold as a supplement | Permitted as a dietary supplement; injectable not FDA-approved |
Frequently asked questions
What is the difference between NAC and Glutathione?
NAC: A glutathione precursor that is FDA-approved as a mucolytic and antidote for acetaminophen overdose, and studied more broadly in psychiatry and respiratory health. Glutathione: The body's master intracellular antioxidant tripeptide, used to support redox balance, detoxification, and skin, with mixed clinical evidence for supplementation.
Which has stronger research evidence, NAC or Glutathione?
This database does not grade compounds. It counts what was run in people: 3 of the 4 studies cited on the NAC profile were human work, against 2 of 3 for Glutathione. Those counts are of our own citation lists and understate any larger literature, and neither is a recommendation.
Are NAC and Glutathione FDA-approved?
NAC: FDA-approved (mucolytic; acetaminophen overdose antidote); also sold as a supplement. Glutathione: Not an approved drug; sold as a supplement (injectable forms flagged by FDA).
Reviewed Sep 2026. This page sets two published records side by side. It is educational, it is not medical advice, and it contains no dosing protocols or recommendations for personal use.