American Society of Hirudotherapy

Hirudin-Like Factor 3 (HLF3, European Medicinal Leeches)

Hidden hirudin-like factor present in H. medicinalis, H. verbana and H. orientalis whose native form has low anticoagulant activity — Müller 2020.

Preclinical / mechanisticLast updated: 2026-05-28 · Reviewed by ASH Editorial Board

Mechanistic Evidence Box

Preclinical / mechanistic
Page type
Compound profile
Evidence type
Hidden hirudin-like factor present in H. medicinalis, H. verbana and H. orientalis whose native form has low anticoagulant activity — Müller 2020.
Evidence level
In vitro
Drug vs leech
Recombinant (genetically expressed)
Safety domains
Bleeding

Clinical translation limit

HLF3's engineered anticoagulant activity in vitro does NOT establish clinical efficacy. No FDA-approved derivative; HLF3 itself is not the FDA-cleared K040187 hirudin family molecule.

Molecular Profile

Category
Anticoagulant
Evidence tier
Preclinical
Source species
Hirudo medicinalis / verbana / orientalis
Discovered
2020 · Müller C et al.
Hirudin-Like Factor 3 (HLF3, European Medicinal Leeches) molecular structure

Biological Targets

  • thrombin (weak in native form; structure-activity engineered enhancement possible)

Key Citations

  1. Müller C et al. (2020), Parasitol Res · PMID 32363441

External Resources

    Related Anticoagulant Compounds

    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.