Living therapy · Drug-discovery frontier

The medicinal leech: a living therapy and a drug-discovery frontier.

The medicinal leech is two things at once. It is a living clinical therapy — FDA-cleared for venous congestion in reconstructive microsurgery, with a growing evidence base across other conditions. And it is a drug-discovery frontier: its salivary secretion, in which mass spectrometry has identified 189 proteins, seeded FDA-approved anticoagulants (bivalirudin in clinical use; lepirudin withdrawn and desirudin discontinued in the U.S.) and remains mostly uncharted. The American Society of Hirudotherapy curates 141 years of evidence for both, verifies every citation, and opens the field to clinicians, researchers, and partners.