Misoprostol is a drug that is Food and Drug Administration (FDA)-approved for the treatment and prevention of stomach ulcers. It is also used to induce labor and as an abortifacient. It is marketed by Pfizer under the trade name Cytotec, but generic versions are available as well.

Chemically, misoprostol is a synthetic prostaglandin E₁ (PGE₁) analogue.

When administered, misoprostol stimulates increased secretion of the protective mucus that lines the gastrointestinal tract and increases mucosal blood flow, thereby increasing mucosal integrity. It is sometimes co-prescribed with non-steroidal anti-inflammatory drugs (NSAIDs) to prevent the occurrence of gastric ulceration, a common adverse effect of the NSAIDs.