Spironolactone 

Spironolactone, a medication used for HTN and fluid retention, has also been used as an adjunct treatment for female pattern hair loss in women who did not respond sufficiently to minoxidil alone. It works by decreasing the production of androgenic hormones and their effects on the scalp follicles that contribute to androgenic alopecia. It decreases testosterone production and competitively blocks androgens at target tissues. Side effects can include weight gain, dehydration, elevated potassium levels, increased urinary frequency, decreased libido, decreased lubrication, sleepiness, and dizziness.

The limitation of this pharmacotherapy is that it only works if taken daily and may become less effective if taken over long periods of time. Due to its impact on testosterone production, this medication is not recommended for men with androgenic alopecia due to its testosterone lowering and feminizing effects, including gynecomastia (or enlargement of male breast tissue), loss of libido, and erectile dysfunction. Like finasteride, women who are pregnant or who are planning to get pregnant cannot take this medication due to the feminizing effects on the external genitalia of male fetuses.