Recent studies suggest that up to three quarters of women are affected by dysmenorrhoea. In up to 15 per cent pain can be severe, limiting daily activities and school or work attendance.

Researchers pooled data from 73 randomised controlled trials, involving 5,156 women. They found that all NSAIDs were highly effective at relieving period pain, apart from aspirin - for which there is only limited evidence of effectiveness.

There was insufficient evidence to show that any one NSAID was superior in terms of safety or efficacy.

The data showed that NSAIDs may be significantly more effective at treating dysmenorrhoea than paracetamol. A review in 2003 had suggested there was no difference.

However, the authors warned that NSAIDs carried a significant risk of adverse effects. They warned women to take NSAIDs with food to cut risks of gastrointestinal symptoms.

'NSAIDs are a highly effective treatment for dysmenorrhoea, though the women using these drugs need to be aware of the significant risk of side-effects such as indigestion or drowsiness,' said the lead author Jane Marjoribanks.

'It would be interesting to see whether these could be reduced, without loss of effectiveness, by combining lower doses with drugs such as paracetamol.'

The authors have called for more trials to compare combination therapies with the use of NSAIDs alone.

Pain is thought to occur during menstruation as prostaglandins stimulate the uterus. NSAIDs such as ibuprofen relieve pain by inhibiting this.

• Cochrane Library online 2010