Androgenetic alopecia in women: why it is different and what options exist in Spain

Androgenetic alopecia in women, which specialists prefer to call female pattern hair loss, is the most common form of chronic hair loss in women and behaves differently from the male form: it thins the centre of the scalp rather than causing a receding hairline and, in most cases, it appears with normal hormone levels. The option with the most trials behind it is topical minoxidil, which in Spain can be bought at the pharmacy without a prescription. Oral minoxidil is not authorised in Spain for hair loss and, like anti-androgens, is only used after a medical assessment; finasteride and dutasteride are contraindicated in women according to their summary of product characteristics.

How to recognise it: the centre thins and the front is preserved

In men, androgenetic alopecia usually starts at the temples and the crown. In women, the typical picture is different: the parting widens, the scalp shows through in the central and upper part of the head, and the frontal hairline is generally kept. The expert committee of the Androgen Excess and PCOS Society described the two usual patterns in 2019: a widening that spreads outwards from the centre, and a pattern with frontal accentuation known as the «Christmas tree» because the parting widens more towards the forehead. It is graded with the Ludwig scale, which we explain alongside what happens in the follicle in why hair falls out in androgenetic alopecia.

What happens underneath is miniaturisation. With each cycle, the hair's growth phase gets shorter and follicles that used to produce a thick hair end up producing a fine, short one, almost a vellus hair, as described in the 2016 Cochrane review of this condition. That is why many women do not see bald patches, but rather a thinner ponytail and hair that no longer covers the way it used to.

It is common and becomes more so with age. In a British study of 377 women seen in dermatology for other reasons, 6 % of those under 50 had this pattern, compared with 38 % of those aged 70 or over (Birch and colleagues, 2001). In an Australian population, hair loss in the mid-scalp affected 57 % of women aged 80 or over (Gan and Sinclair, 2005), and the 2018 European S3 guideline puts the figure at up to 42 % of women.

Why it is different from male baldness

The underlying difference lies in hormones. In men, dihydrotestosterone is the well-known driver of the process. In women, the role of androgens is less direct: the 2019 committee concluded that isolated female pattern hair loss should not be taken as a sign of androgen excess when androgen levels are normal, which is the usual situation. A review published in 2026 in the American Journal of Clinical Dermatology adds that oestrogens may have a protective effect and that genetics shows sex differences in the mechanism.

This fits with the figures rising so much in the years that follow the menopause, although the exact relationship with oestrogens is still being studied. It also explains why treatments designed for men, which focus on curbing dihydrotestosterone, do not carry over unchanged to women.

There is one more difference, which is not biological but matters: the same 2026 review points out that in women this condition is underdiagnosed and undertreated, and that its impact on self-esteem and social life often exceeds that seen in men.

First step: ruling out what is not androgenetic alopecia

Diffuse hair loss in a woman can have several origins, and treatment depends on getting the diagnosis right. The 2026 review lists chronic telogen effluvium, diffuse alopecia areata and scarring alopecias as the diagnoses to tell apart. Sudden, heavy shedding, for example after giving birth, points instead to telogen effluvium, which usually resolves on its own; and if it is the frontal hairline that is receding, it is worth ruling out frontal fibrosing alopecia, one of the scarring alopecias, because there the follicle that is lost does not come back.

The assessment is mainly clinical: history, examination of the scalp and, often, trichoscopy or a pull test. The 2019 committee considers it mandatory to assess possible androgen excess in every patient, and recommends, although as optional, measuring iron, vitamin D, zinc, thyroid hormones and prolactin. The Spanish summary of product characteristics for topical minoxidil itself makes it clear: it is not indicated when hair loss is sudden or patchy, appears after childbirth, when there is no family history or when the cause is unknown.

What options exist and what the evidence says

Topical minoxidil: the foundation with the most trials

It is the most studied treatment in women and, according to the 2026 review, the only one approved by the US FDA for this condition. The Cochrane review pooled 47 trials with 5,290 participants, 17 of them on minoxidil. Compared with placebo, almost twice as many women noticed a moderate or marked increase in hair (risk ratio 1.93), and the total hair count rose by around 13 hairs per square centimetre more than with placebo, with moderate- to low-quality evidence. Adverse effects with the 2 % concentration did not differ significantly from those with placebo.

In Spain it is sold at pharmacies without a prescription, as a 2 % (20 mg/ml) and a 5 % (50 mg/ml) solution, indicated for moderate androgenetic alopecia. Its summary of product characteristics asks for patience: 4 months of treatment may be needed before any signs of growth appear. It is also the starting point proposed by the 2019 committee, which only suggests adding other medicines when hair loss is severe or there is androgen excess.

Low-dose oral minoxidil: an off-label use

The minoxidil tablets authorised in Spain (Loniten and Minogal) are indicated for severe high blood pressure that does not respond to other treatments, not for hair. Using them at low doses for alopecia is use under conditions other than those authorised, which Spain's Royal Decree 1015/2009 treats as exceptional: the doctor must justify it in the medical record, explain the benefits and risks and obtain the patient's consent.

The evidence on effectiveness in women is still limited. A small, 24-week randomised trial (Ramos and colleagues, 2020) compared 1 mg oral with 5 % topical minoxidil: the oral form showed a trend towards greater improvement, but without significant superiority. There is more safety data: a multicentre study of 1,404 patients, 943 of them women, led by dermatologists at the Hospital Ramón y Cajal in Madrid, found hypertrichosis (hair growth in other areas) in 15.1 % and infrequent systemic effects such as light-headedness (1.7 %), fluid retention (1.3 %) or tachycardia (0.9 %); 1.7 % stopped treatment because of adverse effects. It is a retrospective study without a control group, and the full breakdown is in our map of the real adverse effects of low-dose oral minoxidil.

There is also a clear limit for many women: the summary of product characteristics for the tablets does not recommend oral minoxidil during pregnancy or in women of childbearing age who are not using contraception, and hypertrichosis has been reported in newborns exposed during pregnancy.

Anti-androgens: when they come into play

When there is androgen excess or hair loss is severe, the 2019 committee suggests adding an anti-androgen or a 5-alpha-reductase inhibitor to minoxidil. In Spain, spironolactone is authorised for high blood pressure, heart failure and hyperaldosteronism, so for hair it is used off-label. Cyproterone acetate 50 mg does include severe androgenetic alopecia in women with severe androgenisation in its summary of product characteristics, but only when lower doses or other options have not worked. In addition, since 2020 the AEMPS (the Spanish medicines agency) has restricted its use because of the risk of meningioma, observed from 25 mg a day and greater the higher the cumulative dose.

The Cochrane review noted the lack of good-quality trials of spironolactone, cyproterone or dutasteride in women, and the 2026 review stresses that randomised trials including women are still scarce. That is why, when they are considered, it is done case by case and with monitoring.

Finasteride and dutasteride: why they are not the starting point

It is one of the most frequent questions, and in Spain the summary of product characteristics is clear. Finasteride 1 mg is indicated only in men aged 18 to 41 and is contraindicated in women; dutasteride, authorised for benign prostatic hyperplasia, is also contraindicated in women. The reason is pregnancy: by blocking the conversion of testosterone into dihydrotestosterone, they can disrupt the development of the external genitalia of a male foetus. On effectiveness, the Cochrane review did not find finasteride 1 mg to be more useful than placebo in women, across three trials with low-quality evidence. The literature describes off-label use in selected cases, but it is a specialist decision, not a first step.

Laser and other add-ons

Low-level laser combs gave inconsistent results in the Cochrane review: participants did not perceive more improvement than with a sham device, although the hair count did increase. The 2026 review places laser and platelet-rich plasma as add-ons that can complement medical treatment, not as substitutes.

What to take away from all this

Androgenetic alopecia in women is not a milder version of the male form: it has a different pattern, a different relationship with hormones and more diagnoses to rule out, so the order matters, first knowing what it is and then choosing. Today in Spain there is hair loss treatment with a prior assessment, a prescription when appropriate from a registered doctor and ongoing follow-up, which is what we do at AiON. You can check in a few minutes whether the treatment suits your case.