Australian research has shown paracetamol is ineffective at treating back pain and osteoarthritis, despite being a recommended treatment.

A review of 13 clinical trials - published in the British Medical Journal - found the commonly-used drug does not reduce disability nor make any significant improvement to quality of life.

The researchers warned that false benefits of paracetamol can come at the cost of liver health.

A team from the University of Sydney assessed mounds data from the various drug trials, which between them involved more than 5,000 patients.

They concluded that for osteoarthritis in the hip or knee, there is only a small improvement with paracetamol, but it was deemed so small it was “not clinically important”.

“Paracetamol is the most widely used over-the counter medicine for musculoskeletal conditions so it is critical that we review treatment recommendations in light of this new evidence,” said Gustavo Machado, one of the researchers.

“In our research, paracetamol for low back pain and osteoarthritis was also shown to be associated with higher risk of liver toxicity in patients.

“Patients were nearly four times more likely to have abnormal results on liver function tests compared to those taking placebo pills.”