Spironolactone works by blocking androgens from reaching the cells that respond to them. The mechanism happens at the receptor level — meaning Spironolactone doesn't reduce how much androgen your body produces, it reduces how much androgen actually acts on your tissues.
Here's the mechanism in plain language. Androgens — the group of hormones that includes testosterone — circulate through your bloodstream and reach the tissues that have androgen receptors. Skin oil glands have them. Hair follicles have them. Scalp follicles have them. When androgens bind to these receptors, they trigger the downstream effects: increased oil production, terminal hair growth in androgen-sensitive areas, hair follicle miniaturization on the scalp.
Spironolactone occupies the androgen receptors before the androgens can bind to them. With the receptors blocked, the androgens circulating in your bloodstream don't have a way to produce their usual effects on skin and hair. Over time, this means:
- Less oil production from skin glands which gradually reduces the conditions that produce PCOS-pattern cysts.
- Slower growth of unwanted facial and body hair because androgens are no longer signaling those follicles to produce terminal hair growth.
- Reduced hair follicle miniaturization on the scalp which can slow or partially reverse PCOS-related hair thinning.
There's also a secondary mechanism worth knowing about. By reducing the action of androgens on the body broadly, Spironolactone can have an indirect effect on menstrual regularity in women with PCOS. Elevated androgens disrupt the normal ovulation process — when androgens are reduced, cycles often become more regular. See Can Spironolactone regulate my menstrual cycle? below for more on this.
Timeline. Spironolactone works gradually. Most women start to see initial changes in acne around 4 to 6 weeks, with more meaningful improvement at 2 to 3 months. Changes to unwanted facial hair and scalp hair loss are slower — typically 3 to 6 months or longer. This is one of the most important things to know going in: the first month is often where women quit treatments that would have worked. If you're past the expected timeline and the changes aren't there, message your Oana clinician before stopping.