N-Acetylcysteine
Our evidence-based analysis on n-acetylcysteine features 107 unique references to scientific papers.
NOTE: We are updating our coronavirus (COVID-19) page with evidence as it comes in.
Summary of N-Acetylcysteine
Primary information, health benefits, side effects, usage, and other important details
It is invalid to extrapolate from efficacy against the common cold or respiratory tract infections broadly to the novel Coronavirus in particular. For more information, see this page. In any case, we have not reviewed NAC for any viral infection yet, and have no opinion on its efficacy for any of them.
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Human Effect Matrix
The Human Effect Matrix looks at human studies (it excludes animal and in vitro studies) to tell you what effects n-acetylcysteine has on your body, and how strong these effects are.
| Grade | Level of Evidence [show legend] |
|---|---|
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Robust research conducted with repeated double-blind clinical trials |
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Multiple studies where at least two are double-blind and placebo controlled |
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Single double-blind study or multiple cohort studies |
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Uncontrolled or observational studies only |
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Level of Evidence
?
The amount of high quality evidence. The more
evidence, the more we can trust the results.
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Outcome |
Magnitude of effect
?
The direction and size of the supplement's impact on
each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.
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Consistency of research results
?
Scientific research does not always agree. HIGH or
VERY HIGH means that most of the scientific research agrees.
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Notes |
|---|---|---|---|---|
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Minor
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Low See all 4 studies |
N-Acetylcysteine may reduce some symptoms of COPD by acting as a mucolytic agent and reducing sputum formation, but it does not appear to be effective at aiding the lungs themselves or reducing disease progression.
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- | - See all 3 studies |
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Notable
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- See study |
NAC supplementation is able to reliably increase glutathione concentrations in cells specifically
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Minor
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- See study |
A decrease in red blood cell (RBC) lipofuscin content has been seen, which is thought to be secondary to reducing lead toxicity and increasing antioxidative defenses
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Minor
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- See study |
NAC supplementation appears to reduce lead bioaccumulation in red blood cells, although the magnitude is statistically significant it is not overly large
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Minor
|
- See study |
After about two weeks of 2,400mg NAC supplementation, cigarette usage appears to be reduced voluntarily by around 25%.
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Minor
|
- See study |
Preliminary evidence suggests a 31-45% reduction in hair pulling symptoms in persons with trichotillomania when supplementing with 1,200-2,400mg NAC for twelve weeks.
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- | - See study |
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- | - See study |
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- | - See study |
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|
- | - See 2 studies |
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- | - See study |
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- | - See study |
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- | - See study |
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- | - See study |
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- | - See study |
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Notable
|
- See study |
There is a significant reduction of total lesion counts in those who supplement N-Acetylcysteine for at least two months.
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|
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Minor
|
- See study |
Self-reported cravings for cocaine during one day of withdrawal appear to be significantly reduced following 12 hours (although acute cravings after 2 hours of supplementation are not affected); this lasts for 24 hours after cessation.
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Minor
|
- See study |
Supplementation of 2,400mg appears to reduce symptoms of marijuana addiction, although the reductions in symptoms are not overly prominent based on the limited evidence so far.
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- | - See study |
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Studies Excluded from Consideration
Used injections of N-acetylcysteine[1]
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Things to Note
Is a Form Of
Other Functions:
Primary Function:
Also Known As
N-Acetyl Cysteine, NAC, N-Ac
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