American Society of Hirudotherapy

The Effectiveness of Leech Therapy in Chronic Low Back Pain

Hohmann CD, Stange R, Steckhan N, Robens S, Ostermann T, Paetow A, Michalsen A (2018) · Deutsches Ärzteblatt International · n=44

RCT evidence detailTrial reference
GRADE LowCohort / case seriesLeech therapy in other conditions
Sample size of this trial compared with other Leech therapy in other conditions trialsFarzali S 2025181Abtahi-Forooshani MS 202650Aminov R 202548Hohmann CD 201844Cheng SP 200544Bergh A 202142Bilden A 202515Hosseini M 202412Resch JC 20237Nair HKR 20203
This trial (highlighted) by sample size alongside other indexed Leech therapy in other conditions trials. Larger trials generally carry more statistical weight.

Study Profile

Design
two-center, open (unblinded) randomized controlled trial (Berlin)
Sample size (n)
44
Intervention
Single session of local treatment with 4-7 leeches (n=25)
Comparator
Four weekly 1-hour sessions of exercise therapy led by a physical therapist (n=19)
Primary endpoint
Change in average back pain intensity on a 100-mm VAS after 28 days
Primary result
Back pain fell from 61.2 to 33.1 mm with leeches and from 61.6 to 59.8 mm with exercise at day 28 (group difference -25.2 mm, 95% CI -41.0 to -9.45; p=0.0018).
Follow-up duration
56 days
PMID
30636672

Key Findings

  • Pain at day 28: 61.2 to 33.1 mm with leeches vs 61.6 to 59.8 mm with exercise (difference -25.2 mm, p=0.0018)
  • Physical impairment, function and physical quality of life also improved significantly at days 28 and 56
  • Patients expected more from leech therapy, but expectations did not significantly affect the findings

Limitations

  • No blinding
  • Small number of patients (25 and 19 analysed)

Clinical Implications

A single leech session lowered chronic low back pain in the short term and improved function and quality of life over 8 weeks, compared with exercise therapy. The authors name the lack of blinding and the small sample as the main limitations.

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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.