According to On the Pill: A Social History of Oral Contraceptives, 1950-1970:
Pincus, Rock, and their associates conducted the first set of tests using norethindrone and norethynodrel on fifty infertility patients at the Fertility and Endocrine Clinic and the Reproductive Study Center at the Free Hospital for Women, where Rock worked, in 1954 and 1955.
After that experiment, two more experiments were conducted, including one on 23 female medical students at the University of Puerto Rico School of Medicine and another on:
twelve psychotic women (and also sixteen psychotic men) to test the effects of norethynodrel and an estrogenprogesterone combination. The purpose of these trials was not to verify the contraceptive capcity
As explained in The Male Pill: A Biography of a Technology in the Making:
Pincus tested the same hormonal compound he used for his clinical trials with women (Enovid) on eight male mental patients and reported that it had a "definite sterilizing effect" (Vaughan 1972: 40). This was the first— and the last— time that Pincus included men in his trials. The men's mental disorders (they were classified as psychotics) made it difficult to collect semen to measure the effects of the hormonal compounds on sperm production (McLaughlin 1982: 120). Moreover, the men experienced side effects, such as shrunken testicles (Seaman and Seaman 1978: 84).
So it is true that Pincus forced men to undergo such experiment, shrinking their testicles, but is not true that he did this prior to testing on woman.