Historical Timeline
From ancient Egypt to modern genomics
Last updated: March 14, 2026
The medicinal leech has one of the longest histories in medicine — spanning over three millennia from Egyptian tomb paintings to 21st-century proteomics. This timeline traces the major milestones in the science, regulation, and clinical use of Hirudo medicinalis and its bioactive compounds.
Ancient & Classical Period
Egyptian tomb paintings (18th Dynasty) depict leech therapy — among the earliest visual evidence of medicinal leech use in human history.
Nicander of Colophon describes medicinal leech use in Greek texts, providing one of the earliest written accounts of therapeutic leech application.
Galen endorses bloodletting including leeches as part of humoral medicine. His influence will shape medical practice in Europe and the Islamic world for over a thousand years.
Al-Zahrawi (Albucasis) details surgical leech applications in his surgical encyclopedia. Avicenna includes leeches in the Canon of Medicine, systematizing their use for the medieval Islamic medical tradition.
The Leech Craze (1800s)
Peak of medical leech use in Europe. Leech therapy becomes the dominant form of bloodletting, eclipsing lancets and scarification.
Broussais champions aggressive leech therapy in France. France consumes up to 100 million leeches per year. Russia exports 70 million leeches annually. Prices spike and wild populations crash.
John Berry Haycraft discovers anticoagulant activity of leech extract — the first identification of what will later be named hirudin.
Scientific Foundation (1900s)
Franz isolates the hirudin compound, establishing it as a distinct anticoagulant protein produced by the leech salivary glands.
Professor Shchegolev develops artificial leech breeding techniques. The first leech biofactory is established near Moscow.
Medpiyavka (Medical Leech) association established in Moscow for centralized leech breeding and distribution. Operated until 1956.
Fritz Markwardt achieves the first purification of hirudin, enabling structural characterization.
I.P. Baskova begins systematic SGS characterization. Her team discovers destabilase, eglins, bdellins, and calin.
Recombinant hirudin produced for the first time. Roy Sawyer publishes Leech Biology and Behaviour and founds Biopharm in Swansea, Wales.
Modern Era
Microsurgery renaissance: leeches return to the OR for flap and digit salvage.
Association of Hirudologists of Russia and CIS founded, with I.P. Baskova as first president.
Piyavit approved in Russia for thrombosis prophylaxis.
Lepirudin (Refludan) receives FDA approval for HIT. Validates the leech-to-drug pipeline.
Bivalirudin (Angiomax) FDA-approved for PCI anticoagulation.
Desirudin (Iprivask) FDA-approved for DVT prophylaxis. Michalsen publishes first RCT for leech therapy in knee OA.
FDA 510(k) clearance for medicinal leeches (K040187, Ricarimpex SAS) — first living animal to receive FDA device clearance.
Dabigatran (Pradaxa) FDA-approved — first oral direct thrombin inhibitor, derived from hirudin SAR research.
Lepirudin voluntarily withdrawn. AHTA incorporated in the US.
Draft genome assemblies published. 15 anticoagulation factors and 17 antihemostatic proteins identified.
Destabilase crystal structure solved at 1.1 Å resolution.
FDA transfers leech regulatory responsibility from CDRH to CBER.
ASH founded. Over 200 bioactive proteins identified in leech SGS.
What’s Next
Future Directions
- Structure-based drug design: The destabilase crystal structure enables computational screening for novel thrombolytic agents.
- Recombinant leech proteins: Advances in recombinant expression systems are making it feasible to produce individual leech salivary proteins at pharmaceutical scale.
- Expanded clinical trials: Growing interest in rigorous RCTs for off-label indications, including OA, chronic pain, and PVD.
- Genomics-driven discovery: With 434+ protein sequences and full genome assemblies available, bioinformatics pipelines are identifying novel bioactive compounds.