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Acetylcysteine (NAC): uses, side effects & brands
Acetylcysteine loosens mucus and is the antidote for paracetamol overdose. It belongs to the Cough & mucolytic (extra) group. These loosen mucus or calm a cough.
Drug type — dosing is set by your doctor
| Measure | Range |
|---|---|
| Drug class | Cough & mucolytic (extra) |
| Type | Prescription |
| Dose | Individual — ask your doctor or pharmacist |
What it is used for
- Loosening thick mucus in chest conditions such as COPD and bronchitis
- Antidote for paracetamol overdose (given by drip in hospital)
- Nebulised to thin mucus in some lung conditions
Common brand names
- India: Mucomix, Effimucil, NAC
- Worldwide: Mucomyst, Acetadote
Common side effects
- Nausea or vomiting
- Unpleasant sulphur smell or taste
- Skin rash
- Flushing, rash or wheeze during the hospital drip
Before taking it — precautions
- Tell your doctor if you have asthma, as it can trigger wheezing
- Tell your doctor about stomach ulcers
- Effervescent tablets contain salt; tell your doctor if you are on a low-salt diet
When to see a doctor urgently
- Wheezing or chest tightness (urgent)
- Rash, swelling or breathlessness during the drip: tell the nurse at once (urgent)
- Severe or blistering skin rash
Not a prescription — no dose shown. The right dose of acetylcysteine depends on age, weight, kidney/liver function and the condition, so MedDroid does not show a dose here. Always get your dose from a doctor or pharmacist and the leaflet inside the pack. General educational information only.
Frequently asked questions
What should I do after a paracetamol overdose?
Go to hospital immediately, even if you feel well. The antidote works best when started early.
Why does it smell like rotten eggs?
Acetylcysteine contains sulphur; the smell is normal and harmless.
Is NAC a useful antioxidant supplement?
It is sold as a supplement, but evidence for general health benefits is limited. Ask your doctor before taking it.
Explore more
Sources & further reading
- World Health Organization (WHO)
- MedlinePlus — U.S. National Library of Medicine
- Ministry of Health & Family Welfare, India
- Indian Council of Medical Research (ICMR)
Reviewed by Dr. Sanjay Anbu, MBBS. MedDroid is an AI medical assistant and can make mistakes. It provides general health information, not a diagnosis or medical advice — always consult a qualified clinician. In an emergency, contact your local emergency number immediately.