Progesterone therapy in men (transgender women), does not significantly effect, testosterone, libido and weight

[alfredoolivas]

This is a study from a gender reassignment clinic in Ohio that studied the effects of patients who included 100mg of oral progesterone as a part of their gender reassignment therapy compared to patients not including progesterone in their regimen, on "gender affirmation outcomes", such as testosterone levels, libido, etcetera.

Orally, progesterone has a bioavailability of less than 10%, with one study reporting values of 6.2 to 8.6%. Therefore, only 6.8 to 8.6mg of their progesterone medication went systematically in these patients. In adult males, progesterone is produced in small quantities by the adrenal glands and testes.

The average daily production rate ranges from 0.75 to 3 milligrams, with blood serum levels typically between 0.1 and 0.3 nanograms per millilitre. Therefore, given that doses of at least 6.8mg were taken daily, this study offers an insight into what supra-physiological doses of progesterone do to an adult male's endocrinology, such as testosterone levels.

https://www.japha.org/article/S1544-3191(23)00252-2/fulltext

"The addition of progesterone to standard feminising GAHT was associated with greater satisfaction with breast development and improved patient mental health within 6 months compared with standard GAHT regimens alone in this patient population. Progesterone's impact on *libido, testosterone suppression, and weight were nonsignificant.*"

The differences in testosterone and libido, between the groups were not significant as you can see. However, feminizing effects were still seen with there being greater breast development in the progesterone group.

Therefore, we can speculate that progesterone may not be anti-androgenic, at least based on blood values; animal studies have shown progesterone does block the uptake of androgens. Therefore, the anti-androgenic mechanisms of progesterone may occur at a cellular level.

[Kilgore]

@alfredoolivas Welcome to the forum. Glad to have you here!

[alfredoolivas]

@Kilgore Thank you, glad to be here!

[bio3nergetic]

Actually the study tells us nothing about true progesterone since unfortunately they use progestins.

[alfredoolivas]

@bio3nergetic “The vast majority of patients on progesterone were first prescribed micronized progesterone 100 mg (93.1%); the remainder of patients were prescribed intramuscular medroxyprogesterone.”

I had the same concerns as you, given how people refer to progesterone and progestenes synonymously nowerdays. However, there were 29 patients, and 27 were using bio identical micronised progesterone and 2 were using medroxyprogesterone.

So I still think it’s a valuable study on progesterone, and that’s why I went ahead and posted the study.

[bio3nergetic]

@alfredoolivas it appears you are correct on that one! Finally, real progesterone.