N-Acetyl Cysteine

Best for

Ease chronic lung disease symptoms

Likely strong benefit · 200–3600 mg/day for 1–104 weeks · 3 meta-analyses , n=11.9k

105 papers · 2 claims · 224 outcomes scored · 2 positive

Outcomes

What n-acetyl cysteine actually does, by outcome

Each row is one outcome with effect size, evidence base, the dose that worked in trials, and time to first effect. Magnitude tiers come from native-unit MCID where available, Cohen's d otherwise.

Outcome Effect size Evidence Dose Weeks Rank

Ease chronic lung disease symptoms Likely strong benefit

Fewer flare-ups and less daily struggle in chronic airway disease.

9 meta-analyses n=12k 200–3600 mg 1–104 wk #1/3

25999707·26324807·2866607·30975143 +5 more

large

9 meta-analyses n=12k Meta-analyzed I²=89%

200–3600 mg

1–104 wk

#1 /3

Build glutathione antioxidant levels Likely strong benefit

Your cells' main internal antioxidant defense gets deeper reserves.

21 meta-analyses n=663 20–4200 mg 1–26 wk #2/13

16537378·18473409·19666395·21558576 +17 more

large

21 meta-analyses n=663 Meta-analyzed I²=86%

20–4200 mg

1–26 wk

#2 /13

Forms & standardisation

The strongest trial coverage comes from plain oral NAC, usually capsules, tablets, or effervescent tablets. On a label, look for N-acetyl-L-cysteine or N-acetylcysteine, because the molecule itself is the point here, not a fancy blend or a branded herb mix.¹² If a product wraps NAC in a lot of extras, that is marketing, not the core evidence.

Risk profile

Adverse events and known drug interactions

Safety events

Gastrointestinal bleeding severe

Polypectomy (serious adverse event recorded) severe

Haemoptysis during common cold (serious adverse event recorded) severe

severe heartburn (led to medication discontinuation) severe

angioedema severe

COPD exacerbation severe

syncopal episode severe

cardiac arrhythmia / hospitalization due to pancreatitis / hospitalization for suicidality severe

Drug interactions

Nitroglycerin major increases effect

Antitussive Agents major increases toxicity

Acetaminophen major decreases concentration

Antithrombotic Agents major increases toxicity

Antibiotics (Oral) moderate decreases effect

Antithrombotic Agents moderate decreases effect

Cisplatin moderate decreases effect

other moderate unknown

Amikacin moderate decreases effect

Amiodarone minor unknown

Co-studied with

Supplements that share evidence with n-acetyl cysteine

Drug:Clomiphene 9 shared outcomes · d=0.16

Drug:Letrozole 9 shared outcomes · d=0.16

Drug:Prednisone 6 shared outcomes · d=0.49

Drug:Azathioprine 6 shared outcomes · d=0.49

Drug:Chorionic Gonadotropin 6 shared outcomes · d=0.19

Frequently asked

Common questions

Does N-acetyl cysteine thin mucus?

Yes. That is one of its best-supported uses, and the respiratory trials show fewer flare-ups plus easier daily breathing when mucus is part of the problem.¹³

Can you take NAC every day?

Yes, that is how most of the human studies use it, especially for respiratory and antioxidant goals.¹²

Is NAC the same thing as glutathione?

No. NAC is the building block your body uses to make glutathione, which is the antioxidant molecule doing the actual cleanup work.²

Should you take NAC with food?

If NAC bothers your stomach, taking it with food is the easy fix. The trial data is built around regular daily use, not a strict empty-stomach rule.¹²

Track n-acetyl cysteine in the app

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Sources

Generated May 15, 2026