Dysmenorrhoea — painful menstrual periods — is one of the most common gynaecological complaints, affecting an estimated 45–95% of menstruating women according to published prevalence studies. Despite its frequency, period pain is often undertreated and under-discussed in clinical settings. Community pharmacists are frequently the first and sometimes only healthcare professional consulted for menstrual pain.
Primary vs secondary dysmenorrhoea
The clinical distinction matters for pharmacy practice:
Primary dysmenorrhoea is menstrual pain without underlying pelvic pathology. It is caused by prostaglandin-mediated uterine contractions and typically begins within the first two years of menarche. The pain is cramping, lower abdominal, and usually worst on the first one to two days of the period. It may be accompanied by nausea, headache, fatigue, and loose stools.
Secondary dysmenorrhoea is menstrual pain caused by an underlying condition — most commonly endometriosis, adenomyosis, or fibroids. It typically presents later in life, may worsen over time, and is often accompanied by heavy menstrual bleeding, pain between periods, or pain during intercourse.
Community pharmacists are well-placed to identify when the pattern of symptoms suggests secondary dysmenorrhoea and refer to a GP for investigation.
Over-the-counter analgesics
NSAIDs: the first-line treatment
Non-steroidal anti-inflammatory drugs are the evidence-based first-line treatment for primary dysmenorrhoea because they directly inhibit prostaglandin synthesis — the mechanism driving the pain.
| NSAID | OTC availability | Dosing for period pain | Key points |
|---|---|---|---|
| Ibuprofen | Yes (200mg, 400mg) | 400mg three times daily with food | Most widely available; effective for most women |
| Naproxen | Yes (250mg, since 2008 reclassification) | 500mg initially, then 250mg every 6–8 hours | Longer duration of action; convenient for school/work |
| Aspirin | Yes (300mg) | 300–600mg every 4–6 hours | Less effective than ibuprofen; more GI side effects |
| Mefenamic acid | Prescription only | 500mg three times daily | Specifically indicated for dysmenorrhoea; requires GP |
The key pharmacist counselling point is timing: NSAIDs are most effective when taken at the onset of pain (or ideally just before, if the woman can predict her cycle). Starting treatment early — before prostaglandin levels peak — produces significantly better pain control than waiting until pain is established.
Paracetamol
Paracetamol is less effective than NSAIDs for dysmenorrhoea because it does not inhibit peripheral prostaglandin synthesis. However, it is an appropriate alternative for women who cannot take NSAIDs (history of peptic ulcer, asthma exacerbated by NSAIDs, or third trimester of pregnancy). Paracetamol 1g every four to six hours (maximum 4g daily) provides modest analgesic benefit.
Combination therapy — paracetamol plus ibuprofen — can be used when either alone is insufficient. The two drugs act via different mechanisms and can be taken together or alternated.
Codeine combinations
OTC codeine-containing products (co-codamol 8/500, Nurofen Plus) are sometimes sought for severe period pain. Pharmacists should be aware that codeine adds modest analgesic benefit but carries constipation and dependency risks. For period pain inadequately controlled by standard-dose NSAIDs, GP referral for mefenamic acid or hormonal management is more appropriate than escalating to OTC codeine.
Non-pharmacological options
Several non-drug approaches have evidence supporting their use for dysmenorrhoea:
- Heat therapy: Topical heat (40°C) applied to the lower abdomen has been shown in randomised trials to be as effective as ibuprofen for pain relief. Pharmacy-available adhesive heat patches (ThermaCare, own-brand equivalents) provide sustained warmth and are discreet under clothing.
- TENS machines: Transcutaneous electrical nerve stimulation applied to the lower abdomen or lower back has moderate evidence for period pain relief and is available from pharmacies.
- Exercise: Regular physical activity reduces the severity of dysmenorrhoea, likely through endorphin release and improved pelvic blood flow. Pharmacists can mention this as a complementary strategy.
When to refer to a GP
Pharmacists should recommend medical review when:
- Pain is severe enough to disrupt normal activities despite adequate NSAID use
- Pain has worsened progressively over several months or years
- Pain occurs between periods, not just during menstruation
- Heavy menstrual bleeding accompanies the pain (soaking a pad or tampon every hour)
- Pain during intercourse (dyspareunia) is reported
- The woman is over 25 and experiencing new-onset severe dysmenorrhoea (suggesting secondary cause)
- There is a family history of endometriosis
Endometriosis, which affects an estimated 1 in 10 women of reproductive age in the UK according to Endometriosis UK, has a mean diagnostic delay of approximately 7.5 years. Community pharmacists who ask the right questions can help shorten that delay.
The broader context
The government's renewed Women's Health Strategy, announced on 14 April 2026, emphasises that women's health concerns should be taken seriously across all healthcare settings. Period pain is a condition that has historically been dismissed — "just part of being a woman" — and pharmacy is one of the settings where that culture can change, one consultation at a time.
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Sources: NICE CKS Dysmenorrhoea, BNF NSAID monographs, Cochrane reviews on heat therapy and TENS for dysmenorrhoea, Endometriosis UK prevalence data, DHSC Women's Health Strategy 2026, PharmSee pharmacy database.