Mefenamic acid is an anti-inflammatory medicine used to relieve period pain and reduce heavy menstrual bleeding. It works by lowering the level of prostaglandins, the substances that cause the cramping and heavier flow.
It is usually taken with food at the first sign of pain and continued for the first few days of your period. Common side effects include indigestion, nausea and diarrhoea. It is not suitable if you have stomach ulcers, severe asthma or certain kidney problems, so tell our pharmacist about your medical history.