Spironolactone

Believe it or not, useless.

Spironolactone, or spiro for short, is a commonly prescribed antiandrogen that is no better than placebo^[1]. Spironolactone is, at best, able to suppress small amounts of testosterone in conjunction with estradiol, as in levels typically found in natal females. However, it is completely ineffective at suppressing testosterone in the levels required for successful gender-affirming hormone therapy. A typical dose is 100mg daily and a typical hondose is 50mg daily. The medical establishment loves prescribing spiro because it is one of the most commonly prescribed medications and is known to be safe, despite there being much better antiandrogens available like bicalutamide or cyproterone acetate.

References

1. Aly. “A Review of Studies on Spironolactone and Testosterone Suppression in Cisgender Men, Cisgender Women, and Transfeminine People.” Transfeminine Science, 19 Dec. 2018, https://transfemscience.org/articles/spiro-testosterone/. Accessed 2 Feb. 2026.