What do the states mean?+
- Solid: well studied, and it works.
- Half-there: the science is still forming.
- A ghost: almost no real studies.
- Hollow: well studied, and it does not work.
- A cord: the pair itself has been tested together.
- Air: nobody has ever tested this pair.
The full scoring method: How we score
NAC benefits: where the science stands
For liver: not settled yet.
Liver is what most people take NAC for, and the strongest evidence says it does not help: a combined review found no real difference. As of August 2026, the verdicts on this page rest on evidence from 74 trials, drawn from the strongest research among the 926 papers on PubMed that mention NAC. Every claim is checked below.
926 papers on PubMed · evidence from 74 trials
Claim by claim
- LiverThe science is still forming. No real difference found so far.
- Blood sugarThe science is still forming. Results lean positive, but there is not much yet.
- Cravings and addictionThe science is still forming. Results lean positive, but there is not much yet.
- EnduranceThe science is still forming. A safety question was raised; later testing found no change.
See 8 more scored claims+
- InflammationThe science is still forming. The best studies disagree.
- JointsThe science is still forming. No real difference found so far.
- Memory and focusThe science is still forming. Results lean positive, but there is not much yet.
- MoodThe science is still forming. No real difference found so far.
- Muscle sorenessThe science is still forming. The best studies disagree.
- PregnancyThe science is still forming. Results lean positive, but there is not much yet.
- Sprint and repeated-effort powerAlmost no real studies. Nothing clear so far.
- Stress and anxietyThe science is still forming. The best studies disagree.
Pairs people ask about
The 18 sources we read
- 2008Randomized trial · 29 people · no clear effect on muscle sorenesssource
- 2009Meta-analysis · no clear effect on liversource
- 2013Crossover trial · 9 people · a harm signal on endurancesource
- 2016Crossover trial · 8 people · no clear effect on endurancesource
- 2017Meta-analysis · pools 7 trials · no clear effect on endurancesource
- 2018Randomized trial · 63 people · benefit for memory and focussource
- 2018Meta-analysis · benefit for cravings and addictionsource
- 2019Crossover trial · 11 people · no clear effect on endurancesource
- 2019Randomized trial · 32 people · benefit for inflammationsource
- 2020Meta-analysis · pools 24 trials, 1,057 people · small benefit for inflammationsource
- 2020Meta-analysis · pools 28 trials · no clear effect on inflammationsource
- 2022Crossover trial · 20 people · no clear effect on sprint and repeated-effort powersource
- 2022Meta-analysis · no clear effect on mood; no clear effect on stress and anxietysource
- 2022Randomized trial · 74 people · benefit for blood sugar; no clear effect on jointssource
- 2023Randomized trial · 42 people · no clear effect on mood; moderate benefit for stress and anxietysource
- 2024Meta-analysis · small benefit for muscle sorenesssource
- 2024Randomized trial · 230 people · benefit for pregnancysource
- 2025Randomized trial · no clear effect on inflammationsource
Chosen as the strongest evidence out of 926 papers on PubMed. Every row links to its paper.
Fair questions
Does NAC work?+
For liver, it is not settled. No real difference found so far.
Is NAC safe?+
No caution is recorded on this page. That is not a safety guarantee; the studies we read were not safety trials.
Why only 18 sources, when PubMed lists 926?+
The 926 is every paper that mentions NAC in any way: animal studies, blood measurements, papers where it is a side note. The strongest sources are combined reviews, and each one already gathers every trial its authors could find. Our 18 cover 74 trials between them, and every one is linked above. Both counts are measured, not estimated.