American Society of Hirudotherapy

Leech therapy compared with electroacupuncture for moderate knee osteoarthritis: a randomized non-inferiority trial

Cui Y, Zhang X, Wang H, Liu J, Li M (2024) · Chinese Medicine · n=144

RCT evidence detailTrial reference
Sample size of this trial compared with other Knee Osteoarthritis trialsWang H 2018264Lauche R 2025240Lauche R 2014237Farzali S 2025181Cui Y 2024144Andereya S 2008113Andereya S 2008113Sarbaev IS 201996Isik M 201790Khoshnevisan A 202280
This trial (highlighted) by sample size alongside other indexed Knee Osteoarthritis trials. Larger trials generally carry more statistical weight.

Study Profile

Design
multicenter (4 sites), open-label, randomized non-inferiority trial (Beijing, Shanghai, Guangzhou, Chengdu)
Sample size (n)
144
Intervention
Three sessions of 4-6 Hirudo nipponia leeches periarticular knee, weekly for 3 weeks
Comparator
Electroacupuncture 30 minutes per session, 3 times per week for 4 weeks (12 sessions total)
Primary endpoint
WOMAC pain at week 8 (non-inferiority margin: 5 points)
Primary result
WOMAC pain reduction 28.4 in leech vs 27.1 in electroacupuncture at week 8 (between-group difference 1.3, 95% CI -3.8 to 6.4) — non-inferiority margin met
Effect size (Cohen's d)
0.04
Follow-up duration
16 weeks

Key Findings

  • Largest multicenter RCT for hirudotherapy in any indication (n=144)
  • Non-inferiority to electroacupuncture established — clinically equivalent effect
  • Three-session leech protocol vs 12-session electroacupuncture — leech more time-efficient
  • Used Hirudo nipponia (Chinese medicinal leech) — different from European species
  • Cost-effectiveness favored leech (¥850 per course vs ¥1,400 for 12 acupuncture sessions)

Limitations

  • Open-label
  • Non-inferiority design less informative than superiority — doesn't prove leech is better
  • Electroacupuncture comparator may itself have limited evidence of efficacy
  • Chinese context — generalizability to Western clinical practice partial
  • No biomarker endpoints

Clinical Implications

Cui 2024 is the largest hirudotherapy RCT to date and establishes non-inferiority versus electroacupuncture, the most popular CAM modality for knee OA in East Asia. For clinicians in integrative-medicine practices, this trial supports offering leech therapy as a more time-efficient alternative to multi-session electroacupuncture with equivalent outcomes. The data are robust enough that knee OA clinical guidelines from Asian CAM societies are likely to incorporate leech therapy at the same evidence level as electroacupuncture going forward.

Related Trials

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.