How do you take Acetylcysteine?

For mucus and catarrh: dissolve one Fluimucil 600 mg effervescent tablet in a half glass of water and drink it once daily. You can take it with or without food. Do not swallow the tablet whole — always dissolve it in water first. Drink plenty of water throughout the day to help loosen the mucus.

What are the side effects of Acetylcysteine?

Nausea or feeling like you want to vomit, stomach upset or diarrhoea, headache, mild skin rash, bad smell from the mouth (the medicine has a sulphur-like smell)

Who should not take Acetylcysteine?

People who are allergic to acetylcysteine, people with active stomach ulcers or bleeding in the stomach, children under 2 years old without a doctor's prescription, and people with severe asthma (it may worsen wheezing in some cases).

OTC

Mucolytic (mucus thinner)

Acetylcysteine

Q: What is Acetylcysteine used for?

Chest congestion, stubborn cough with thick mucus (catarrh), bronchitis, paracetamol (Panadol) overdose, chronic obstructive lung disease

Last reviewed June 2026

Who is this for?

What is this drug?

Acetylcysteine is a medicine that works by breaking down thick, sticky mucus in your chest and airways, making it easier to cough out. It can also protect the liver from damage caused by paracetamol overdose.

What is it used for?

Chest congestionstubborn cough with thick mucus (catarrh)bronchitisparacetamol (Panadol) overdosechronic obstructive lung disease

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Cough & Cold

How it works

Breaks disulfide bonds in mucoproteins through its free thiol (-SH) groups, reducing mucus viscosity and facilitating clearance of respiratory secretions. Additionally, replenishes hepatic glutathione stores, restoring the antioxidant defence system and preventing hepatocellular damage in paracetamol toxicity.

Available Over The Counter

Get this from any pharmacy or chemist — no prescription needed.

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What to watch out for

Always buy from a reputable pharmacy — Fluimucil is a well-known brand in Nigeria, so make sure the packaging looks genuine and check the expiry date. Do not use this medicine to treat dry cough without mucus — it is meant for wet, productive cough with catarrh. If your symptoms do not improve after 5 to 7 days, see a doctor rather than continuing to self-medicate.

Common Side Effects

Nausea or feeling like you want to vomit
stomach upset or diarrhoea
headache
mild skin rash
bad smell from the mouth (the medicine has a sulphur-like smell)

Serious Side Effects

Severe allergic reaction — swelling of the face
lips
or throat with difficulty breathing (rush to the hospital immediately). Vomiting blood or severe stomach pain. Wheezing or tightness in the chest that gets worse instead of better.

Drug Interactions

Do not take acetylcysteine at the same time as antibiotics like amoxicillin or tetracycline — separate them by at least 2 hours, as it can reduce how well the antibiotic works. Avoid using it together with cough suppressants (medicines that stop you from coughing) because you need to cough out the loosened mucus. If you take activated charcoal, it may reduce how well acetylcysteine works.

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Pregnancy & Breastfeeding Warning

Consult your doctor before taking acetylcysteine if you are pregnant or breastfeeding — it should only be used if your doctor says the benefit is worth it.

Who Should NOT Take This

People who are allergic to acetylcysteine
people with active stomach ulcers or bleeding in the stomach
children under 2 years old without a doctor's prescription
and people with severe asthma (it may worsen wheezing in some cases).

How to Store

Store in a cool, dry place away from direct sunlight and heat — Nigerian weather can be very hot, so avoid leaving it on windowsills or in your car. Keep the tablets sealed in their original container to protect from moisture and humidity. Always keep out of reach of children.

For information only — not medical advice. Always talk to a doctor or pharmacist before changing your medication.