American Society of Hirudotherapy

Diverse molecular data demonstrate that commercially available medicinal leeches are not Hirudo medicinalis

Research article published in Proceedings. Biological sciences (2007)

Last Updated: March 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Genomics & ProteomicsSalivary PharmacologySiddall M et al. · Proceedings. Biological sciences, 2007

Abstract

The European medicinal leech is one of vanishingly few animal species with direct application in modern medicine. In addition to the therapeutic potential held by many protease inhibitors purified from leech saliva, and notwithstanding the historical association with quackery, Hirudo medicinalis has been approved by the United States Food and Drug Administration as a prescription medical device. Accurate annotation of bioactive compounds relies on precise species determination. Interpretations of developmental and neurophysiological characteristics also presuppose uniformity within a model species used in laboratory settings. Here, we show, with mitochondrial sequences and nuclear microsatellites, that there are at least three species of European medicinal leech, and that leeches marketed as H. medicinalis are actually Hirudo verbana. Beyond the obvious need for reconsideration of decades of biomedical research on this widely used model organism, these findings impact regulatory statutes and raise concerns for the conservation status of European medicinal leeches.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Publication typeComparative StudyJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, Non-P.H.S.
Indexed MeSH termsAllelesAnalysis of VarianceAnimalsBase SequenceCommerceDNA PrimersDNA, MitochondrialEuropeLeechesMicrosatellite RepeatsModels, GeneticMolecular Sequence Data

Summary

The European medicinal leech is one of vanishingly few animal species with direct application in modern medicine. In addition to the therapeutic potential held by many protease inhibitors purified from leech saliva, and notwithstanding the historical association with quackery, Hirudo medicinalis has been cleared by the United States FDA via 510(k) premarket notification...

Why This Matters for Hirudotherapy

Expands the genomic and molecular understanding of medicinal leeches and their bioactive repertoire.

Citation

Diverse molecular data demonstrate that commercially available medicinal leeches are not Hirudo medicinalis.

Siddall M et al. · Proceedings. Biological sciences, 2007

Added to ASH library: March 18, 2026 · Site last updated: March 18, 2026

This website provides educational information and does not constitute medical advice, diagnosis, or treatment recommendations. Medicinal leech therapy carries clinically meaningful risks and should be performed only by qualified clinicians under institutionally approved protocols. FDA 510(k) clearance for medicinal leeches is limited to specific indications; investigational and off-label discussions are labeled accordingly. For patient-specific guidance, consult a qualified healthcare provider.

Diverse molecular data demonstrate that commercially available medicinal leeches are not Hirudo medicinalis | ASH