Why you might not be buying the right pain relief for period cramps

Many women may not be using the most effective pain medication for period cramps, according to a big study of supermarket till receipts.

A decade of loyalty card data across 211 million transactions in an unnamed chain of high street stores in England found paracetamol was the most common painkiller bought alongside tampons and sanitary towels.

But experts say ibuprofen could be a better choice for many because it is more effective at dealing with muscle cramps.

The transactions reveal the "scale and impact" of period pain and how people manage it, which has not been studied much before, say the researchers.

Paracetamol is perhaps more familiar to people which might explain why it was bought more often, they suggest.

While still an effective painkiller, ibuprofen can be a better choice for period pain because it blocks the production of prostaglandins - the chemical responsible for causing the cramping contractions of muscles in the womb.

Paracetamol, meanwhile, works primarily in the brain to block pain signals, making it a good choice for headaches. It also helps manage a high temperature, so can be useful if you have flu, for example.

Researchers looked at purchases from 3.4 million shoppers between 2006 and 2015.