Mefenamic acid is a non-steroidal anti-inflammatory drug used to treat pain, including menstrual pain. It is commercially available as Ponstel®. It is also prescribed as an antipyretic drug. It is typically prescribed for oral administration.

Mefenamic acid decreases inflammation (swelling) and uterine contractions by a still unknown mechanism. However it is thought to be related to the inhibition of prostaglandin synthesis.

Since hepatic metabolism plays a significant role in mefenamic acid elimination, patients with known liver deficiency may be prescribed lower doses. Kidney deficiency may also cause accumulation of the drug and its metabolites in the excretory system. Therefore patients suffering from renal conditions should not be precribed mefenamic acid.