Chronic Low Back Pain (nonspecific)
One small, unblinded randomized trial (Hohmann 2018, n=44): back pain was lower 4 weeks after leech therapy than after exercise therapy; follow-up 8 weeks.
Patient Summary
- Is this FDA-cleared for this use?
- No — investigated off-label. The FDA cleared medicinal leeches in 2004 only for venous congestion in microsurgical reconstruction (K040187). Use for chronic low back pain is supported by one small published trial but not FDA-evaluated.
- What evidence exists?
- One randomized trial (Hohmann 2018, 44 patients) compared leech therapy with exercise therapy: four weeks later, back pain was clearly lower in the leech group, and function and physical quality of life were also better at four and eight weeks. The trial was small, patients knew which treatment they received, and nobody was followed beyond eight weeks, so the result needs to be confirmed. Leech therapy does not replace staying active, exercise therapy, or a medical check of back pain with warning signs.
- Main risks
- Bleeding and oozing from each bite site for several hours, sometimes up to 24 hours
- Itching, redness, and irritation at the bite sites lasting days to weeks
- Mild anemia if many leeches are used (uncommon with a single session)
- Local skin infection or, rarely, Aeromonas infection from leech gut bacteria
- Allergic reaction to leech saliva (uncommon)
- Small bite marks that usually fade over weeks to months (rarely a pale spot stays longer)
- Who should not consider this
- Patients taking blood thinners such as warfarin, apixaban, rivaroxaban, dabigatran, or heparin
- Patients with hemophilia or other inherited bleeding disorders
- Patients with anemia
- Patients with a weakened immune system, especially severe neutropenia
- Patients with back pain with warning signs (fever, a recent fall or injury, cancer history, loss of bladder or bowel control, numbness in the groin) until a doctor has checked it
- Pregnant patients (leech therapy is not done during pregnancy)
- What to ask your clinician
- Has my back pain been checked for warning signs, and does it need imaging first?
- Have I tried staying active and exercise therapy, and what does my doctor or physical therapist recommend?
- What is the realistic chance leech therapy will help me, and for how long?
- What evidence does the practitioner rely on, and have they treated patients like me before?
- Are leeches from an FDA-registered supplier and used only once?
- What antibiotic, if any, will I be given for Aeromonas prevention?
- What is the cost and is it covered by insurance? (typically not covered as it is off-label)
- When to seek urgent care
- Loss of bladder or bowel control, or numbness in the groin or inner thighs (go to the ER immediately)
- New or worsening weakness in a leg
- Severe back pain with fever
- Bleeding from a bite site lasting more than 24 hours or soaking through dressings
- Spreading redness, warmth, pus, red streaks, or increasing pain around the bite sites
- Hives, facial or tongue swelling, throat tightness, or breathing difficulty
What this does NOT mean
- It does not mean leech therapy is FDA-cleared for low back pain — it is not.
- It does not mean the effect is proven — it comes from one small trial in which patients knew their treatment.
- It does not mean leech therapy replaces staying active, exercise therapy, or a medical check of back pain with warning signs.
- It does not mean the benefit lasts — the trial followed patients for only eight weeks.
Safety cross-references
Clinical Profile
- Category
- Musculoskeletal
- ICD-10
- M54.50, M54.59
- Safety tier
- Medium
Evidence Summary
One randomized controlled trial has tested leech therapy for chronic low back pain (Hohmann 2018, Dtsch Arztebl Int; two centers in Berlin; registration DRKS00004871). It randomized 44 patients to local leech therapy (n=25) or to exercise therapy led by a physical therapist (n=19). Average back pain on a 100-mm visual analogue scale 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); physical impairment, function and physical quality of life also improved significantly at days 28 and 56. The authors name the lack of blinding and the small sample as the main limitations; follow-up ended at day 56. No other randomized trial in chronic low back pain was identified, so the effect needs confirmation. Leech therapy is not a substitute for evaluation of red-flag back pain (fracture, infection, tumor, cauda equina syndrome) or for established treatments such as staying active and exercise therapy.
What the books describe
Below is a summary of what books on hirudotherapy say about this condition. These are the authors’ observations, not a proven effect and not a promise of results. Hirudotherapy has contraindications; the decision is made by a physician.
- Baskova and Isakhanyan do not write separately about chronic nonspecific low back pain: their section is devoted to vertebrogenic (spine-related) radiculopathies — pain associated with damage to a nerve root in osteochondrosis of the spine[B1].
- Baskova and Isakhanyan write that the analysis of studies on hirudotherapy of vertebrogenic radiculopathies is “encouraging,” and that, according to the current views they refer to, leeches can be prescribed in any clinical form of spinal osteochondrosis — as treatment aimed at the mechanism of the disease or as a means of relieving spine-related pain; at the same time they note that effective methods of treating spinal pain syndrome have still not been developed[B1].
- Flecken and Michalsen call hirudotherapy an excellent alternative for vertebrogenic pain syndromes, especially when the physical examination reveals painful hardening of muscles and connective tissue along the spine; in their words, it often relieves such pain immediately and thereby improves the conditions for physical therapy and exercise therapy, which are also required[B3].
- For pain in the lower back (lumbago) they stipulate separately: before treatment starts, a lumbar disc herniation and other primary causes of the pain must be excluded[B3].
- In the chapter on the scientific basis of the method, in the section on myofascial pain syndrome, Michalsen writes that lower back pain and sacroiliac joint pain are commonly and successfully (by subjective assessment) treated with leeches, but the corresponding data from clinical trials are lacking, and he adds that no scientific assessment of the efficacy in these conditions is possible at present[B3].
- Both books list hemophilia and concurrent use of anticoagulants (medicines that reduce blood clotting) among the contraindications[B1][B3].
- Flecken and Michalsen add that aspirin and clopidogrel are not contraindications in themselves, but that at the first session the number of leeches should be reduced and the patient should be asked about a tendency to bleed[B3].
Treatment specifics
How many leeches, where they are placed, how long a session lasts, and whether to repeat are clinical decisions made by a qualified provider under institutional protocol — not something to self-administer. Discuss the specifics with a clinician experienced in medicinal leech therapy. (Clinicians: where the society's reference books describe a protocol, it is shown in the clinician view — switch the audience selector in the top bar to “Clinician”.)
Key Trials
- Hohmann CD et al. (2018), n=44 · Dtsch Arztebl Int · PMID 30636672 · ASH analysis →
Detailed Trial Entries
1 trial indexed in the ASH RCT Library with full Study Profile, GRADE rating, and clinical implications:
Contraindications
- Hemophilia or another bleeding disorder
- Taking anticoagulants (blood thinners such as warfarin or heparin)
- Anemia or suppressed blood formation
- Low blood pressure, shock, collapse or fainting
- Severe wasting (cachexia)
- Intolerance of leeches or a history of severe allergic reactions
- Pregnancy
- Stomach or duodenal ulcer, erosive gastritis
- Acute infectious disease or high fever
- Severe unstable illness, markedly weakened immunity (for example during chemotherapy) or HIV infection
- Drinking alcohol at the time of treatment
- No consent from the patient
- Back pain with red flags (suspected fracture, infection, tumor or cauda equina syndrome) until it has been evaluated
Related Conditions
Lumbar Radiculopathy (Sciatica)
Investigational use for lumbar radiculopathy; the closest randomized evidence is in chronic low back pain (Hohmann 2018, n=44), not radicular pain.
Sciatica (Non-Discogenic / Piriformis)
Investigational use for non-discogenic sciatica including piriformis syndrome; no controlled trial, only an old unquantified Russian case series.
Myofascial Pain Syndrome (Investigational Adjunct)
Investigational adjunct for chronic myofascial trigger-point pain; one small randomized trial (n=66) and Russian clinical series only; dry needling, manual therapy, and exercise remain primary.
Knee Osteoarthritis
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.
References
- [B1]
Баскова И.П., Исаханян Г.С. Гирудотерапия. Наука и практика [Hirudotherapy: Science and Practice]
Monograph in Russian, 506 pp., ISBN 5-89527-058-1. Chapter 15: sensation at the bite, length of the session; secretion kininases and pain.
- [B3]
Michalsen A., Roth M., Dobos G. Medicinal Leech Therapy
ISBN 978-3-13-143581-1 / 978-1-58890-563-5. Chapter 9, p. 107: perceptions of the bite — a local dragging pain lasting around one to five minutes.
The information on this page is based on the hirudotherapy books listed under References and reflects the experience their authors describe. Sensations and results differ from person to person. This information is not medical advice, a diagnosis or a prescription, and it does not replace an examination by a physician. Do not stop or change any prescribed treatment without your physician. Hirudotherapy has contraindications.