N-Acetyl cysteine (NAC)
Full ranking Dose tool Products (830)
Key facts
Daily Value (US FDA)—
Tolerable Upper Intake Level (UL)— Reference upper value (cited, not a UL): 600 mg
Median (Per day)300 mgP5 41.7 – P95 800
Products830
Sources: https://webprod.hc-sc.gc.ca/nhpid-bdipsn/atReq?atid=n-acetyl-l-cysteine2&lang=en · Health Canada NNHPD monograph: not to exceed 600 mg NAC/day
Daily dose across products (mg/day)
Reference upper value (cited, not a UL) 600
5 mglog scale · n=8303,000 mg
Label data from official national databases and brand websites, as declared; not lab-verified.
Common questions
Is there an official upper limit for N-Acetyl cysteine (NAC)?
No UL has been set. We use a cited reference upper value of 600 mg per day. It comes from the linked study or assessment and is not a regulatory limit. [source]
How much N-Acetyl cysteine (NAC) do products usually contain per day?
As of 2026-11-01, 830 products list a comparable daily dose (833 dose records; one product can have several). The median is 300 mg per day, and 90% of records fall between 41.7 and 800 mg. Figures come from labels and are not lab-tested. [source]
Top ranked
| Rank | Brand | Product | Per day | Score |
|---|---|---|---|---|
| 1 | Nature's Sunshine | N-Acetyl Cysteine | 600 mg | 100.0 |
| 1 | Swanson | N-Acetyl Cysteine 600 mg | 600 mg | 100.0 |
| 1 | XYMOGEN | NAC N-Acetyl Cysteine | 600 mg | 100.0 |
| 4 | GNC | N-Acetyl-L-Cysteine NAC 600 mg | 600 mg | 97.8 |
| 4 | Twinlab | NAC (N-Acetyl-Cysteine) | 600 mg | 97.8 |
For information only; not medical advice. Talk to a doctor or pharmacist before starting or stopping any supplement.