Spironolactone for hair loss in women: how it works, the evidence and when it may be considered

Spironolactone is a prescription-only medication that was originally developed for high blood pressure and to remove excess fluid. It also has an antiandrogenic effect, meaning it dampens the influence of male sex hormones. This is the basis for its use against hereditary hair loss in women.

One important point up front: for hair loss, spironolactone is not approved in Germany. Here it is prescribed off-label and dispensed only on prescription. Whether it is medically suitable for you is something a doctor decides on a case-by-case basis. It is used above all in premenopausal women, usually together with topical minoxidil. For men, it is not suitable for hair loss. What is established, how robust the evidence really is, which side effects are possible and who the active ingredient may be considered for, we explain here calmly.

What spironolactone is and how it works against hair loss

Spironolactone is what is known as an aldosterone antagonist. In its original role it acts on the kidney and is used for high blood pressure, certain types of oedema and disorders of the hormone aldosterone. For hair loss, a second effect matters: spironolactone acts as an antiandrogen.

In hereditary hair loss in women, androgens, that is male sex hormones, play a central role. At androgen-sensitive hair roots they cause the follicles to shrink over time. The hairs become thinner, shorter and eventually barely visible. This process is called miniaturisation. The role the hormone DHT plays in this is explained in the article DHT and hair loss.

Spironolactone intervenes at this point. It occupies the binding sites where androgens would need to dock, and it additionally dampens their production in the body.¹ This is intended to slow the miniaturisation of the follicles. The active ingredient does not conjure up new, denser hair. It aims to slow the progressive process and preserve existing hair.

Why its use against hair loss is off-label

In Germany, spironolactone is approved as a cardiovascular medication, for example for high blood pressure and to remove excess fluid. Hair loss is not among the approved indications.² If a doctor nevertheless prescribes the active ingredient for hereditary hair loss, this is done off-label.

Off-label does not mean that a treatment is dubious. In dermatology, this use is established. The responsibility, however, lies entirely with the prescribing doctor, who weighs the benefits and risks for your case and accompanies you. Spironolactone is prescription-only, so you can only obtain it with a doctor's prescription.

How good is the evidence in women?

The evidence is limited. Large, long-running and placebo-controlled studies are largely lacking; most of the knowledge comes from smaller and retrospective investigations. Proof of efficacy at the level expected of an approved medication does not exist for spironolactone in hair loss.

What the available data show: in an analysis of five mostly non-placebo-controlled studies with just over 400 women, hair loss improved in roughly half of those treated. Without a placebo group, however, this proportion cannot be cleanly separated from the natural course and from concurrent effects. Together with topical minoxidil, the result was clearly better than with spironolactone alone.¹ Only a small, genuinely placebo-controlled study in premenopausal women, all of whom additionally used topical minoxidil, was able to test the effect against a dummy medication: with spironolactone, the appearance of the hair improved markedly more often than with placebo.⁴

The European treatment guideline lists spironolactone as one option in premenopausal women, as a rule combined with minoxidil.³ An important caveat comes with this: those most likely to benefit are women in whom there are signs of an increased androgen influence, for example in the context of polycystic ovary syndrome. Without such signs, the benefit is less clearly established.³

Who spironolactone may be considered for and who it is not

Who receives spironolactone and who does not depends on sex, hormonal status and pre-existing conditions:

• More likely to be considered: women with hereditary hair loss, primarily before menopause, especially where there are signs of an increased androgen influence such as polycystic ovary syndrome, blemished skin or increased body hair growth. Often as an addition to topical minoxidil, less often on its own.³
• Not suitable: men. In them, the antiandrogenic effect can lead to breast growth and sexual dysfunction; for male hair loss there are other, better-studied approaches.²
• Contraindications: an already elevated potassium level, severe kidney weakness, and potassium-raising concurrent medications such as ACE inhibitors and sartans, potassium supplements or other potassium-sparing diuretics. The active ingredient is also not used during pregnancy and breastfeeding, more on this below.⁵

Whether spironolactone can be considered at all in your case is something only the medical review of your health information determines.

Side effects and what doctors watch for

As an antiandrogen and a fluid-removing agent, spironolactone comes with its own side-effect profile.¹ The most important:

• Cycle and hormone effects: menstrual disturbances occur relatively often and were an important reason for discontinuing treatment in studies. Breast tension or tenderness is also possible.
• Circulation and fluid loss: because the active ingredient removes fluid, increased urination, dizziness or light-headedness and a drop in blood pressure are possible.
• Potassium in the blood: spironolactone can raise the potassium level, known as hyperkalaemia. In otherwise healthy women who take it for hair loss, this rise usually stays small and without symptoms. With impaired kidney function or together with potassium-raising medications, however, it can rise sharply and disturb the heart rhythm, in rare cases up to life-threatening cardiac arrhythmias.⁵

That is why spironolactone belongs under medical supervision. Depending on the starting situation, the doctor monitors potassium, kidney values and blood pressure, especially at the start and when risk factors or other medications are present. New symptoms such as severe dizziness, muscle weakness or heart palpitations should be checked with a doctor early.

Spironolactone when trying to conceive and during pregnancy

Spironolactone should not be used during pregnancy, and certainly not for hair loss. In the prescribing information, pregnancy is listed as a contraindication.⁵

The background: as an antiandrogen, spironolactone could theoretically disturb the development of the external genitalia of a male foetus. This is documented from animal studies with high doses. Experience in humans so far, however, points to a low risk of malformations, even though the data basis is small.⁶ Spironolactone is therefore not among the active ingredients with an absolute, well-documented risk of harm, as applies for example to the 5-alpha-reductase inhibitors. That is not a free pass. For hair loss, the active ingredient is not used during pregnancy, because there is no reason to take on a theoretical risk.

In practical terms, this means: anyone taking spironolactone for hair loss should not be pregnant or wish to become pregnant, and should use reliable contraception during use. If you wish to conceive, the active ingredient is not a suitable path. During breastfeeding, it is likewise not used in connection with hair loss. These questions are clarified in advance by the medical review.

How a treatment works in practice

Spironolactone for hair loss is a long-term therapy, not a short course. It takes patience before anything shows: a reliable assessment is usually only possible after six to twelve months of regular use.³ The effect only lasts as long as the active ingredient is taken. After stopping, the androgen-driven process continues from where it would be without treatment.

In most cases spironolactone is combined with topical minoxidil, because the evidence for this combination is better than for spironolactone alone.¹ How minoxidil works and where it also plays a role as a tablet, you can read in the article oral minoxidil. A broader overview of causes and treatment approaches in women is given in the article hair loss in women.

One brief outlook: in the USA, spironolactone is also offered as a topically applied variant, in the hope of fewer side effects throughout the body. Robust studies on this are lacking so far, and in Germany there is no established ready-made medicinal product for it. Here, it is the oral form that plays the role in everyday practice.

Whether a drug therapy makes sense for you and which path fits depends on your findings, pre-existing conditions and your own preferences. This decision is not made by a questionnaire, but by a doctor. With us, you answer an online medical questionnaire for this, our doctors review your information, and if you wish, a German partner pharmacy handles the dispensing. A doctor only issues a prescription if a treatment is medically suitable. How this works is explained in the article How the health questionnaire works.