A retail pharmacy group says people are failing to properly read the labels of cold and flu remedies.
Care Chemist, which represents more than 250 retail pharmacies, says some people risk liver damage by taking paracetamol in doses that are much too high.
Chief executive officer Nicolette McDonald says she was prompted to issue a warning after a conversation with a doctor.
The Pharmacy Guild of New Zealand says the recommended dose of paracetamol is four grams per day.