In pharmacology, the term mechanism of action refers to the specific biochemical interaction through which a drug substance produces its pharmacological effect. A mechanism of action usually includes mention of the specific molecular targets to which the drug binds, such as an enzyme or receptor.

For example, the mechanism of action of aspirin involved irreversible inhibition of the enzyme cyclooxygenase, which suppresses the production of prostaglandins and thromboxanes thereby reducing pain and inflammation.

Pharmacology | Medicinal chemistry