Guaifenesin
Guaifenesin is a expectorant found in 14 medicines sold in India, such as Ascoril LS, Ambrodil-LX, Kofarest-LS. Below: what it is for, how it works, how to take it, side effects, interactions and pregnancy advice.
Also called: guaiphenesin
What it is used for
Helps bring up phlegm in a chesty cough.
How it works
An expectorant that is thought to make mucus thinner and more watery, so a chesty cough is more productive.
How to take it
Adults usually take 200 to 400 mg every 4 hours as syrup or tablets. Drink plenty of fluids.
Common side effects
- Nausea
- Vomiting
- Stomach upset
- Dizziness
Get medical help straight away if
- Cough lasts more than 3 weeks, or you cough up blood
- Rash
Be careful
Drink plenty of water; not for children under 6 without advice.
Other medicines and interactions
Often combined with cough suppressants, which work in the opposite direction; avoid such mixes for a wet cough.
Pregnancy and breastfeeding
Avoid in the first three months of pregnancy; ask a pharmacist later in pregnancy or while breastfeeding.
Combination medicines that contain Guaifenesin (14)
Common questions
What is Guaifenesin used for?
Helps bring up phlegm in a chesty cough.
How does Guaifenesin work?
An expectorant that is thought to make mucus thinner and more watery, so a chesty cough is more productive.
How should I take Guaifenesin?
Adults usually take 200 to 400 mg every 4 hours as syrup or tablets. Drink plenty of fluids.
What are the side effects of Guaifenesin?
Common: Nausea, vomiting, stomach upset, dizziness. Get help straight away for: Cough lasts more than 3 weeks, or you cough up blood, rash.
Does Guaifenesin interact with other medicines?
Often combined with cough suppressants, which work in the opposite direction; avoid such mixes for a wet cough.
Is Guaifenesin safe in pregnancy and breastfeeding?
Avoid in the first three months of pregnancy; ask a pharmacist later in pregnancy or while breastfeeding.
Does Guaifenesin need a prescription in India?
It is usually sold without a prescription in India, but ask a pharmacist if you take other medicines or have a long-term illness.
Which brands contain Guaifenesin?
Ambrodil-LX, Ambrolite Levo, Ascoril LS, Asthalin AX, Chericof-LS, Deletus LS, Indikof LS, Kofarest-LS, Kofirax, Mucaryl LS, Reswas LS, Salbetol LS, Solvin LS, Zerotuss XP.
Sources and further reading
- Guaifenesin: NHS · MedlinePlus
NHS (UK National Health Service) and MedlinePlus (US National Library of Medicine) are free, reviewed medicine guides. Brand names and doses there may differ from India.
Last reviewed 31 October 2026. Written by Satya Babu from standard prescribing information.
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