Joseph Wetherill Eschbach (January 21, 1933 – September 7, 2007) was an American doctor and kidney specialist whose twenty years of research starting in the 1960s led to an improvement in the treatment of anemia.

Working with a hematologist, Dr. John W. Adamson, Eschbach looked at various forms of renal failure and the role a natural hormone, erythropoietin, had in preventing anemia.

By studying the urine of sheep and other animals in the 1970s, the two scientists helped establish that erythropoietin did stimulate the bone marrow to produce red blood cells.

The trial was successful, and its results were published in The New England Journal of Medicine in 1987: Administering artificial erythropoietin did reverse anemia in kidney patients.

His research helped to inform and lead to the Food and Drug Administration's 1989 approval of the replacement hormone Epogen.