He co-founded Case Western Reserve University School of Medicine's Gender Identity Clinic in 1974, served as the chair of the World Professional Association for Transgender Health (WPATH) drafting committee for the 5th edition of their Standards of Care (SOC-5) published 1998, and served on the American Psychiatric Association (APA) DSM-IV (1994) Subcommittee on Gender Identity Disorders.

[citation needed] His early work focused on premature ejaculation and erectile dysfunction, and he has written on a number of treatment options, including vacuum pumps,[2] injections into the corpus cavernosum of the penis,[3] and Viagra.

[non-primary sources needed] In 1974 he created the Case Western Gender Identity Clinic to treat transgender people which recommended surgery for only 10% patients and he became an influential figure in trans healthcare in the 70s and 80s.

[11]In the 1990's, scientific consensus on transgender healthcare began to diverge from psychoanalytic theories as gender-affirming medical care was seen as more effective than therapy for treating gender dysphoria.

[1] Levine was named Chair of the fifth edition of the World Professional Association for Transgender Health (WPATH) Standards of Care (SOC) in 1998,[12] the last iteration to include "autogynephilia.

[14][1] He argued that WPATH's biennial meetings being open to transgender people who weren't medical professionals limited "the ability for honest and scientific debate".

[11] He has argued the mainstream medical establishment has moved to the fringe on transgender healthcare and that groups such as the APA were endorsing WPATH's updated SOC "on the basis of civil rights" instead of scientific evidence.

[1][14] He works as the Gender Dysphoria Consultant for the Massachusetts Department of Corrections and denied all applications for surgery he received, arguing the patients wanted to transition due to sexual deviance, unresolved trauma, or to escape the moral opprobrium of their crimes.