Millions of people reach for paracetamol when period pain strikes, but a new study has found that ibuprofen is actually the more effective choice — and the reason lies in how the two drugs work inside the body.
Researchers from the University of Bristol and the University of Nottingham analysed more than 211 million supermarket receipts from 2006 to 2015, published in the journal PLOS Digital Health. They found that one in four shoppers overall — 26.7% — bought pain relief alongside menstrual products such as pads and tampons. Among those specifically buying period products, 50% also included some form of painkiller. Of those, two-thirds were paracetamol and only one-third were ibuprofen, despite the latter being the more effective treatment for menstrual cramps.
The study also uncovered a stark socio-economic divide. People living in low-income areas were 32% less likely to purchase pain relief alongside period products than those in higher-income areas, a gap attributed to affordability. “Using shopping data, we can see just how widespread the need for pain relief really is,” said Dr Anya Skatova of the University of Bristol. “This kind of evidence helps make menstrual pain visible at a population level and provides a strong foundation for systemic change in how it is recognised, treated, and prioritised in public health.”
Why ibuprofen is more effective for period pain
Ibuprofen belongs to a class of drugs known as non-steroidal anti-inflammatory drugs (NSAIDs). It works by directly targeting the underlying cause of period pain. During menstruation, the body releases chemicals called prostaglandins, which cause the muscles of the womb to contract, leading to pain and cramps. Dr Giuseppe Aragona, medical adviser for Prescription Doctor, explained: “Ibuprofen … works by reducing the production of prostaglandins. By addressing the process that is driving the pain in the first place, ibuprofen can often provide better relief than paracetamol alone.”
Paracetamol, in contrast, blocks pain signals from reaching the brain but does not have the same anti-inflammatory effect and does not reduce prostaglandin production. While it can take the edge off mild symptoms, it is often less effective for moderate to severe menstrual cramps. Studies cited in the research briefing show that NSAIDs are significantly more effective: if 18% of women taking a placebo achieved moderate or excellent pain relief, between 45% and 53% of those taking NSAIDs would do so. Ibuprofen can also reduce menstrual flow by 20% to 60%.
Despite these advantages, Dr Aragona noted that paracetamol remains a useful option for people who cannot take ibuprofen — for example, those with NSAID-triggered asthma, stomach ulcers, or kidney problems. “Paracetamol works differently, helping to reduce the perception of pain, but it does not have the same anti-inflammatory effect,” he said.
For those prone to cramping, taking ibuprofen preventatively — before pain sets in — may help. “The aim is to reduce prostaglandin production before levels build up,” Dr Aragona said, though he cautioned that people should follow dosing instructions and seek advice from a pharmacist or GP if unsure.
Other options and systemic challenges
Beyond ibuprofen and paracetamol, other NSAIDs such as naproxen and mefenamic acid are also effective for period pain because they reduce prostaglandins and inflammation. Some research suggests combining an NSAID with paracetamol can be more effective than either drug alone, addressing both the source of pain and how the brain processes it. For those who prefer non-medication approaches, heat pads, hot water bottles, gentle exercise, and massage can offer relief.
Hormonal contraception is another option. The combined oral contraceptive pill, hormonal IUDs, implants, and injections can suppress ovulation and reduce prostaglandin production, leading to lighter and less painful periods. Hormonal IUDs are particularly effective, often resulting in significantly reduced pain and many users ceasing to have periods entirely after a year.
Yet the scale of the problem goes beyond which pill to take. A 2025 survey by Wellbeing of Women, titled “Just a Period,” of more than 3,000 people found that 50% of women had seen a healthcare professional about heavy bleeding or period pain, and another 50% had their symptoms dismissed by someone in their lives — whether a male healthcare professional (17%) or a partner (26%). Fifty-one per cent said having a period negatively impacts their life. Endometriosis UK reports that the average wait for an endometriosis diagnosis in the UK has risen to nine years and four months. Of those surveyed by the charity, 39% had to visit their GP at least ten times before being referred for diagnosis, 55% went to A&E with symptoms, and 46% were sent home without any treatment.
Period poverty exacerbates these inequalities. The shopping data study showed that those in low-income areas are less likely to afford pain relief, while stigma and dismissal of symptoms prevent many from seeking help. Dr Aragona advised that anyone experiencing severe period pain that is worsening, interfering with daily life, or accompanied by heavy bleeding, pain during sex, or fertility concerns should speak to their GP.