Spironolactone can interfere with estrogen production and metabolism, leading to potential changes in estrogen levels. Some studies suggest that spironolactone may have anti-estrogenic effects, which could impact estrogen-regulated processes in the body.

The role of spironolactone in the aetiology of gynaecomastia was examined in terms of its ability to bind to the oestrogen receptor in cytosol, to cause specific oestrogenic effects in the absence of endogenous oestrogen and to be antioestrogenic in the presence of oestradiol.

Spironolactone metabolism in humans. [242] Canrenone may be further reduced (into di-, tetra-, and hexahydrogenated metabolites), hydroxylated, and conjugated (e.g., glucuronidated). [242] Spironolactone is rapidly and extensively metabolized in the liver upon oral administration and has a very short terminal half-life of 1.4 hours.

A 2 sysreview of 18 studies found that spironolactone shows no significant effects on levels of estrogen, estradiol, testosterone, androstened, dehydroep sulfate, luteinizing hormone, or follicle-stimulating hormone in women. [145]

Spironolactone is a potassium-sparing diuretic and structural antagonist of aldosterone (van Zuuren et al., 2012a) and acts as an androgen antagonist by competitively blocking androgen receptors as well as inhibiting ovarian androgen production. The usual daily dose is 100 to 200 mg.