Best NAC Supplement (2026): Cost per Day and Label Comparison
Our pick: Nutricost NAC 600 mg, $0.10 per 600 mg at Nutricost’s list price. Its label says 1 capsule a day. 1 of 8 on a public testing list (Thorne, NSF/ANSI 173).
Not all the same dose: most are 600 mg a capsule, but Thorne is 500 mg and Toniiq is 1,300 mg in 2 capsules. Compare cost per 600 mg in the table. Research and dose: see the NAC guide and the NAC dosage guide. This page does not claim NAC treats any condition.
What NAC is
NAC (N-acetylcysteine) is a form of the amino acid cysteine. Your body can use the cysteine in NAC to make glutathione, an antioxidant your cells make. Researchers say this matters most when glutathione runs low, and that NAC is likely to do little in cells that already have enough .(Rushworth 2014).
Research on downstream outcomes is mixed, and this page makes no claim that NAC treats or prevents any condition.
NAC vs glutathione supplements
People often wonder whether to take NAC or glutathione directly. NAC costs less per day than most glutathione products, and the absorption of oral glutathione is debated. Glycine is the other glutathione building block.
Best NAC, ranked by cost per 600 mg
| Product | Dose / form | Bottle (list price) | Cost per 600 mg | Label says | Testing list | Buy |
|---|---|---|---|---|---|---|
| BulkSupplements NAC powder | 600 mg a scoop (powder) | $22.97 for 250 g (about 417 scoops of 600 mg) | $0.055 | 600 mg (about ¼ teaspoon) up to three times a day | None found | Buy |
| Nutricost NAC 600 mg Our pick | 600 mg a capsule | $17.97 for 180 capsules | $0.10 | 1 capsule a day | None found | Buy |
| Toniiq NAC 1300 | 650 mg a capsule (1300 mg in 2) | $29.97 for 240 capsules | $0.12 | 2 capsules a day on an empty stomach | None found | Buy |
| Life Extension NAC 600 mg | 600 mg a capsule | $11.25 for 60 capsules | $0.19 | 1 capsule one to three times a day | None found | Buy |
| NOW NAC 600 mg | 600 mg a capsule | $47.99 for 250 capsules | $0.19 | 1 capsule twice a day | None found | Buy |
| Jarrow N-A-C Sustain 600 mg | 600 mg a tablet, slow-release | $21.99 for 60 tablets | $0.37 | 1 tablet once or twice a day, on an empty stomach if possible | None found | Buy |
| Thorne NAC 500 mg | 500 mg a capsule | $33.00 for 90 capsules | $0.44 | 1 capsule two or three times a day | NSF/ANSI 173 | Buy |
| Pure Encapsulations NAC 600 mg | 600 mg a capsule | No list price | No list price | 1 capsule one to three times a day, between meals | None found | Buy |
Most of these are 600 mg a capsule, so cost per 600 mg is the main difference. Thorne NAC 500 mg is the only one on a public testing list. Jarrow N-A-C Sustain is the only slow-release tablet; Life Extension and NOW are plain 600 mg capsules.
Verification check · NAC
What we could and could not verify about NAC
1 of the 8 is confirmed in NSF/ANSI 173: Thorne NAC 500 mg (90 Capsules). The other 7 products we track are not listed in any registry we checked. That means nobody independent has confirmed them; it is not evidence against them.
Method: our NAC roster matched against the full public registries of third-party-certified supplements in the US, NSF/ANSI 173, USP Verified and Informed Sport, 5,317 listings, retrieved 2026-08-25. Absence means nobody independent has checked that NAC product, not that it failed. Full method and limitations.
Frequently asked questions
What does NAC do?
Your body can use the cysteine in NAC to make glutathione, an antioxidant your cells make. Researchers say this matters most when glutathione runs low, and that NAC is likely to do little in cells that already have enough (Rushworth 2014). This page does not claim NAC treats any condition; ask your clinician about any health question.
How much NAC?
Most products here are 600 mg a capsule; Thorne is 500 mg and Toniiq 1,300 mg in 2 capsules. The bottles we compared say to take 600 to 1,800 mg a day: from 1 capsule a day (Nutricost) up to 3 a day (Life Extension, Pure Encapsulations). For any health question, ask your clinician.
NAC or glutathione?
NAC is usually cheaper per day than glutathione. Oral glutathione absorption is debated.
Related guides
Sources
- Rushworth GF, Megson IL. "Existing and potential therapeutic uses for N-acetylcysteine: the need for conversion to intracellular glutathione for antioxidant benefits." Pharmacol Ther. 2014. PMID: 24080471
- Product labels and list prices: NIH Dietary Supplement Label Database and each brand’s own store, read October 15, 2026. Testing lists: NSF/ANSI 173, NSF Certified for Sport, USP Verified, Informed Choice and Informed Sport.
- Tenório MCDS, et al. "N-Acetylcysteine (NAC): Impacts on Human Health." Antioxidants. 2021;10(6):967. PMID: 34208683