Bloodletting was dismissed in the 1870s. The first double blind rct was 1943.

Additionally, we use leeches for certain situations.

In the last 25 years leech therapy has made a comeback in the area of microsurgery and reimplantation sur­gery. Hirudo medicinalis can secrete several biologically active substances including hyaluronidase, fibrinase, proteinase inhibitors, and hirudin, an anticoagulant.

The leech can help reduce venous congestion and prevent tissue necrosis. In this way it can be used in the postoperative care of skin grafts and reimplanted fingers, ears, and toes. Because of concern regarding second­ary infections a “mechanical leech” has been developed at the University of Wisconsin.