The painkiller effects of leech application were ascertained in many trials on patients with osteoarthritis who claimed that leeching was more relieving than topical diclofenac with no adverse effects.
Likewise, some studies proved that hirudin can reduce synovial inflammation in arthritis patients by inhibiting DING protein, a derivative of synovial stimulatory protein acting as autoantigen in rheumatoid arthritis patients.
In another study, a group of women with osteoarthritis of the first carpometacarpal joint received a treatment course by 2-3 leeches locally. All treated individuals revealed less pain and disability improvement.
The efficacy of leeching was observed after 1 week of therapy and lasted for at least 2 months.