Health & fitness · dietary supplement
N-acetylcysteine (NAC) supplement
Hacker Approved
People recommend NAC as a cheap, generally safe supplement that they say helps with hangovers, brain fog, and stress, and that is widely studied. Critics say long-term safety data is limited and that it can worsen liver damage if taken after drinking.
Summarized from 24 comments.
People recommend NAC as a cheap, generally safe supplement that they say helps with hangovers, brain fog, and stress, and that is widely studied. Critics say long-term safety data is limited and that it can worsen liver damage if taken after drinking.
- recommend
- 17
- criticize
- 5
- months recommended
- 5 of 13
Why people love it
Generally safe, low risk · 2
It seems to be safe overall and safe during pregnancy, and will prevent any potential depletion of glutathione stores
Nov 2025 · commentgenerally it's a safe thing with a low chance of making anything worse
Apr 2026 · commentHelps with hangovers and alcohol damage · 2
It's also very effective at helping reduce the damage of alcohol, if you take it before drinking.
Jan 2026 · commentthe effect is clear and reproducible. My hangovers are also less bad.
Apr 2026 · commentMany studies across conditions · 3
it has racked up papers showing its efficacy in a truly staggering number of illnesses and conditions
Jan 2026 · commentHighly recommend reading the actual literature on its effects
Jan 2026 · commentRead the molecular biology papers.
Jan 2026 · commentPersonal experiences of benefit · 2
it helps with brain fog also! Plus it reduces stress and irritability.
Jul 2026 · commentI used NAC supplement for 1 year and it changed my life
Jan 2026 · comment
What people warn about
Possible liver damage after drinking · 2
post-treatment with NAC aggravated ethanol-induced hepatic lipid peroxidation and worsened acute ethanol-induced liver damage
Jan 2026 · commentcan actually do more liver damage if taken after drinking than just taking nothing
Aug 2026 · commentLong-term safety data limited · 2
research about the safety of taking NAC every day for the long term is limited
Apr 2026 · commentTaking it for a long time can reduce these levels, creating multiple secondary problems.
Jan 2026 · commentCancer risk in mouse study · 2
One of the side effects in a study in mice was inducing lung cancer
Apr 2026 · commentNAC causes cancer in humans.
Nov 2025 · comment
Long-term owners
I used NAC supplement for 1 year and it changed my life
Jan 2026 · comment
What hackers pick instead
- Creatine monohydrateA heavily studied, widely considered safe supplement that people credit with strength gains and sharper thinking, especially when sleep deprived; some report hair loss, stomach trouble or disrupted sleep.104recommend
- MelatoninRecommended for helping people fall asleep, often at low or liquid doses. Common caveat: morning grogginess, and evidence is weak outside jet lag and sleep disorders.43recommend
- Magnesium glycinateRecommended for better sleep, relaxation, and relief from restless legs and muscle stiffness. Some users found no effect, and overdose is easy to happen.31recommend
- Psyllium huskA simple, cheap fiber supplement people use for hard stools and digestion. The main caveat is that it tastes and feels unpleasant.13recommend
- Magnesium L-threonatePeople recommend it for sleep and muscle tightness; critics say the brain benefit claims rest on a mouse study and the patent holder's research.9recommend
Every quote
The 24 most detailed of 24 comments. Each links to the original.
It seems to be safe overall and safe during pregnancy, and will prevent any potential depletion of glutathione stores
Recommends · Nov 2025 · in “No credible tie between Tylenol use and autism/ADHD study finds”
it has racked up papers showing its efficacy in a truly staggering number of illnesses and conditions
Recommends · Jan 2026 · in “Scientists unlock brain's natural clean-up system for new treatments for stroke”
It's also very effective at helping reduce the damage of alcohol, if you take it before drinking.
Recommends · Jan 2026 · in “Scientists unlock brain's natural clean-up system for new treatments for stroke”
Taking it for a long time can reduce these levels, creating multiple secondary problems.
Mixed · Jan 2026 · in “Scientists unlock brain's natural clean-up system for new treatments for stroke”
it helps with brain fog also! Plus it reduces stress and irritability.
Recommends · Jul 2026 · in “Scientists reverse brain aging, with a nasal spray”
generally it's a safe thing with a low chance of making anything worse
Recommends · Apr 2026 · in “The Mystery in the Medicine Cabinet: Acetaminophen, ibuprofen, and what to know”
the effect is clear and reproducible. My hangovers are also less bad.
Recommends · Apr 2026 · in “The Mystery in the Medicine Cabinet: Acetaminophen, ibuprofen, and what to know”
Highly recommend reading the actual literature on its effects
Recommends · Jan 2026 · in “Scientists unlock brain's natural clean-up system for new treatments for stroke”
I used NAC supplement for 1 year and it changed my life
Recommends · Jan 2026 · in “Scientists unlock brain's natural clean-up system for new treatments for stroke”
Read the molecular biology papers.
Recommends · Jan 2026 · in “Scientists unlock brain's natural clean-up system for new treatments for stroke”
post-treatment with NAC aggravated ethanol-induced hepatic lipid peroxidation and worsened acute ethanol-induced liver damage
Criticizes · Jan 2026 · in “Scientists unlock brain's natural clean-up system for new treatments for stroke”
can actually do more liver damage if taken after drinking than just taking nothing
Criticizes · Aug 2026 · in “The Quest for a Hangover Cure”
research about the safety of taking NAC every day for the long term is limited
Criticizes · Apr 2026 · in “The Mystery in the Medicine Cabinet: Acetaminophen, ibuprofen, and what to know”
One of the side effects in a study in mice was inducing lung cancer
Criticizes · Apr 2026 · in “The Mystery in the Medicine Cabinet: Acetaminophen, ibuprofen, and what to know”
NAC causes cancer in humans.
Criticizes · Nov 2025 · in “No credible tie between Tylenol use and autism/ADHD study finds”
it's causing side effects like anhedonia, apathy, minor sleep disruptions, or other subtle negative effects
Mixed · Jan 2026 · in “Scientists unlock brain's natural clean-up system for new treatments for stroke”
I can't say I've noticed that particular effect, but I do seem to sleep a bit better on those nights.
Mixed · Apr 2026 · in “The Mystery in the Medicine Cabinet: Acetaminophen, ibuprofen, and what to know”
NAC is one of the only known treatments for trichotillomania
Recommends · Jul 2026 · in “Scientists reverse brain aging, with a nasal spray”
Glycine + NAC even better, both precursors for Glutathione
Recommends · Apr 2026 · in “The Mystery in the Medicine Cabinet: Acetaminophen, ibuprofen, and what to know”
They still tend to work better than the western remedies
Recommends · Apr 2026 · in “The Mystery in the Medicine Cabinet: Acetaminophen, ibuprofen, and what to know”
Also works wonders for COVID spike protein detox.
Recommends · Jul 2026 · in “Should DayQuil Be Legal?”
it was a surprisingly smooth experience
Recommends · Sep 2026 · in “People hooked on vapes try a new way to quit: cigarettes”
So if you insist, maybe take some NAC.
Recommends · Jul 2026 · in “No link between acetaminophen use during pregnancy and adverse birth outcomes”
Apparently NAC might has side effects of its own.
Criticizes · Apr 2026 · in “The Mystery in the Medicine Cabinet: Acetaminophen, ibuprofen, and what to know”
Counts from 1,795,640 Hacker News comments, Nov 2025 to Nov 2026. How we count · Report a mistake