Smart Library

FDA-cleared application: medicinal leech therapy to relieve venous congestion in compromised tissue flaps awaiting vascular ingrowth.

FDA-cleared application: post-replantation venous decompression in digits, ears, scalp, and partial avulsion injuries.

FDA-cleared application: venous decompression of compromised DIEP, TRAM, and latissimus dorsi flaps in post-mastectomy reconstruction.

Off-label use; several small RCTs in knee OA report pain and function improvement with leeches versus NSAID gel, sham leech or TENS, though results against sham and TENS are mixed, and a 2022 trial against physiotherapy found no therapeutic effect.

Off-label use with one small RCT (Michalsen 2008, 32 women) in which single-session leech therapy reduced pain and improved hand function more than topical diclofenac for about 2 months.

Off-label use with one small RCT (Bäcker 2011, n=40) in which a single leech session reduced pain more than topical diclofenac at day 7; the pain difference was no longer significant at day 45.

Investigational use; no clinical study of leech therapy for plantar fasciitis was identified, and the rationale is mechanistic only.

Off-label adjunct to compression; the evidence is one small open-label randomized trial in varicose veins (n=50) and a 20-patient uncontrolled series.

Off-label adjunct to compression therapy; the evidence is one 20-patient uncontrolled series in complicated varicose veins plus case reports.

Investigational use; no controlled trial was identified, and the only clinical report is a 1998 conference series of 87 patients without a comparison group.

Investigational use for chronic rhinosinusitis; no clinical study of leech therapy for this condition was identified, and the rationale is mechanistic.

Investigational use for cervical radiculopathy; no verifiable published trial specific to this indication.

Investigational use for lumbar radiculopathy; the closest randomized evidence is in chronic low back pain (Hohmann 2018, n=44), not radicular pain.

Investigational use; the only clinical evidence is a 7-patient case series and a 26-patient non-randomized pilot, and the proposed mechanism is hypothetical.

Investigational use for chronic tension-type headache; no study for this headache type was identified, and the proposed mechanism (muscle tension, venous congestion) is untested.

Investigational adjunctive use with only non-randomized clinical reports identified; proposed mechanisms are blood-volume removal and hirudin effects on vessels; not a substitute for pharmacotherapy.

Investigational use for symptomatic relief of varicose tributary discomfort and inflammation; does not eliminate underlying venous reflux.

Investigational use for symptomatic relief of grade II-III internal/external hemorrhoidal disease; does not address anatomic prolapse.

Investigational adjunctive use in primary open-angle glaucoma; weak case-series evidence. Not a substitute for IOP-lowering eye drops or surgery.

Investigational use for dry eye disease; no clinical study of leech therapy was identified, and the proposed meibomian-gland mechanism is hypothetical.

Investigational adjunctive use proposed for non-suppurative lactational mastitis; no clinical study of leech therapy was identified.

Investigational use only: no clinical study of leech therapy for fibromyalgia was identified, and it is not a primary treatment.

Investigational use for non-discogenic sciatica including piriformis syndrome; no controlled trial, only an old unquantified Russian case series.

Investigational use for primary Raynaud's phenomenon; the only clinical report is three patients in a 2025 Azerbaijani case series, with no controlled trial.

Investigational use for primary livedo reticularis; no clinical study was identified. Secondary causes (lupus, APLAS) require rheumatology referral.

Investigational use for chronic lipodermatosclerosis; no study in this condition was identified, only small series in venous ulcer and varicose disease.

Investigational use for insulin injection-related lipohypertrophy nodules; no clinical study of leech therapy for them was identified.

Investigational use for androgenic alopecia; the only clinical report is a single-patient Ayurvedic case study, with no controlled trial.

Investigational use for erythematotelangiectatic rosacea; no clinical study of leech therapy was identified.

Investigational adjunct, not a primary treatment; a few small, mostly uncontrolled studies report lower PASI scores.

Investigational use for localized refractory eczema; evidence is limited to a few small studies without placebo or standard-care controls.

Investigational use for keloid and hypertrophic scars; evidence is limited to one small uncontrolled series and two conflicting single-patient reports.

Investigational use for chronic recurrent (non-acute) cellulitis with underlying lymphedema or venous insufficiency.

Investigational adjunctive use; no clinical study of leech therapy for lymphedema was identified.

Investigational adjunctive use after breast cancer treatment with axillary node dissection; no clinical study of leech therapy was identified.

Investigational use for acute monoarticular gout when NSAIDs and colchicine are contraindicated; evidence limited to a few small Ayurvedic pilot studies.

Investigational use for chronic mid-substance Achilles tendinopathy; evidence limited to isolated single-patient reports.

Investigational use for non-surgical rotator cuff tendinopathy and chronic shoulder impingement; evidence limited to isolated case reports.

Investigational use for stenosing tenosynovitis of the digital flexor pulleys; evidence limited to a single Ayurvedic case report.

Investigational use in Dupuytren's disease; evidence limited to one uncontrolled Russian-language report in patients with contracture.

Investigational use for plantar fascia nodules in early Ledderhose disease; no clinical study of leech therapy for this condition was identified.

Investigational use for stable-phase Peyronie's disease; evidence limited to one uncontrolled Russian series of 29 patients. Standard treatments (verapamil, collagenase, surgery) remain first-line.

Investigational for category III CP/CPPS: evidence is limited to a 3-patient case report and an uncontrolled Russian series; multimodal therapy remains standard.

Investigational adjunctive use for chronic endometriosis-related pelvic pain; very limited evidence. Not a substitute for hormonal or surgical management.

Investigational for primary dysmenorrhea; one small randomized trial of leeches plus cupping versus an oral contraceptive pill reported lower pain scores.

Investigational for non-specific chronic pelvic pain; the only clinical report located is an uncontrolled 60-woman series in which leeches were one part of multimodal care.

Investigational for tinnitus; small non-randomized studies, mostly Russian, report less ear noise, and no study using the Tinnitus Handicap Inventory was identified.

Investigational adjunct for Ménière's disease with no clinical study identified; standard management (diet, betahistine, intratympanic therapy) remains primary.

Investigational use for residual symptoms in the post-acute phase of DVT (>6 weeks); contraindicated in acute DVT.

Not recommended: the only published report of leech therapy in hidradenitis suppurativa describes a harmful outcome.

Cecropin-homolog antimicrobial peptide identified in the leech salivary secretome.

Macin-family broad-spectrum antimicrobial protein identified in leech immune tissue and salivary secretome.

Macin-family antimicrobial protein with reported neuronal-tissue specificity — leech innate immunity component.

Dorsal random skin-flap rat model: medicinal leech application + leech saliva extract injection both increase VEGF, neovascularisation + reduce necrosis vs control — Ünal 2025.

11-mer antimicrobial peptide RK22 from Hirudinaria manillensis salivary-gland transcriptome — Lu 2023 demonstrates MRSA killing + biofilm eradication.