ingestible · for acute bronchitis & cough
N-Acetylcysteine (NAC)
Reviewed by the Nimbera editorial team · Last updated May 2026
How to use
Take 600 mg NAC orally once or twice daily with food and a full glass of water. Available as effervescent tablets (dissolve in water) or standard capsules. For acute bronchitis, continue for 5-10 days. For chronic bronchitis prevention, longer courses are used under medical supervision.
How it works
NAC is a precursor to glutathione and directly cleaves disulfide bonds in mucus glycoproteins, reducing sputum viscosity and making mucus easier to clear. It also replenishes glutathione in bronchial epithelial cells, reducing oxidative stress and inflammatory signaling that perpetuates airway inflammation.
Where to buy
NAC supplements at health food stores, pharmacies, and online (Jarrow, NOW Foods, Thorne). Effervescent sachets are common in European pharmacies (e.g., Fluimucil). Also available as prescription mucolytic in some countries.
Typical cost: $10-$25 for a month's supply of 600 mg capsules.
Safety notes
May interact with nitroglycerin (causes headache) and activated charcoal. Rare side effects include nausea, vomiting, and skin rash. Those with asthma should use with caution as inhaled NAC can trigger bronchospasm. Consult a doctor before use if you take blood thinners.
Drug & supplement interactions
- Always tell your doctor or pharmacist about any supplements you take.
- Interactions can occur with prescription medications, blood thinners, and immunosuppressants.
- Herbal remedies can affect how the body absorbs or metabolises drugs.
- Check drugs.com interactions checker before starting.
Clinical source
Cazzola M et al., Influence of N-acetylcysteine on chronic bronchitis or COPD exacerbations: a meta-analysis, Eur Respir Rev, 2015This information is compiled from primary clinical literature and is for informational purposes only. It is not a substitute for professional medical advice. Read our full disclaimer.