Chronic Fatigue Syndrome / ME (Investigational)

Patient Summary

Is this FDA-cleared for this use?

Not FDA-cleared for chronic fatigue syndrome (ME/CFS). FDA cleared medicinal leeches only for venous congestion in microsurgical reconstruction (K040187, June 2004). Use for ME/CFS is investigational.

What evidence exists?

Tier C (investigational). Only anecdotal reports; there are no randomized controlled trials. Evidence-based management of ME/CFS per IOM/NAM criteria and CDC guidance: pacing and energy management, treatment of comorbidities (orthostatic intolerance with fluid/salt/compression, sleep disorders, mood symptoms), avoiding graded exercise therapy in those with post-exertional malaise (NICE 2021 reversed prior recommendation), and symptom-targeted pharmacotherapy. Low-dose naltrexone and antiviral trials in selected cases.

Main risks

• Bleeding from bite sites for 6 to 24 hours after detachment
• Trigger of post-exertional malaise lasting days to weeks from procedure stress
• Worsening of fatigue, brain fog, or orthostatic symptoms
• Local skin infection or, rarely, Aeromonas infection
• Allergic reaction to leech saliva (uncommon)
• Risk of vasovagal episode in patients with autonomic dysfunction
• Delay of pacing, energy management, and comorbidity treatment
• Risk of missed underlying treatable cause (thyroid, sleep apnea, anemia, depression)

Who should not consider this

• Patients without thorough workup for treatable causes (thyroid, anemia, sleep apnea, depression, B12, Lyme, etc.)
• Patients with severe ME/CFS who are bed-bound (procedure-induced PEM risk too high)
• Patients with orthostatic intolerance, POTS, or severe autonomic dysfunction
• Patients on anticoagulants, with hemophilia, or with severe anemia
• Pregnant patients
• Patients who have not engaged with pacing and energy management

What to ask your clinician

• Have I been worked up for treatable causes (thyroid, sleep apnea, anemia, depression, B12, Lyme)?
• Has my orthostatic intolerance been managed (fluid, salt, compression, sometimes midodrine or fludrocortisone)?
• Have I learned pacing and energy management to avoid post-exertional malaise?
• Am I a candidate for low-dose naltrexone trial?
• Are my comorbidities (sleep, mood, pain) being addressed?
• What evidence specifically supports leech therapy for ME/CFS?
• What is the realistic risk of triggering post-exertional malaise from the procedure?

When to seek urgent care

• Severe new symptoms after the procedure that do not resolve in days
• Sudden palpitations, severe dizziness, or syncope (worsening orthostatic intolerance)
• Spreading redness, warmth, pus, or red streaks (cellulitis)
• Fever above 38.0 C / 100.4 F or chills
• Bleeding from a bite site lasting more than 24 hours
• Hives, facial or tongue swelling, throat tightness, or breathing difficulty
• New chest pain, shortness of breath, or signs of cardiac event