Hair loss in women: a map of the causes, tests and treatments

When your hair becomes thin, the first question is "what is it?" and the second is "what can be done?". This page answers the first briefly and refers you to the detailed page on each cause. It is best not to skip the diagnosis, because the treatment is chosen according to the cause. The path looks like this: understand what is happening, and then choose a treatment.

What can you see in the mirror, and what does it usually mean?

The way the hair becomes thin points to the likely cause, but only an examination confirms it. The following chart summarizes the common patterns:

Shedding or thinning: what's the difference?

Shedding means hairs falling out, and thinning means hairs becoming finer, and the two conditions require different approaches. In temporary shedding (telogen), a large number of hairs enter the shedding phase all at once, usually after an event such as illness, childbirth or a deficiency. In female pattern hair loss, the hairs gradually become shorter and finer, so the thinning progresses slowly¹.

There is also an in-between condition: prolonged temporary shedding known as chronic telogen effluvium. It is described mainly in women aged 30 to 60, begins suddenly and fluctuates over time, and a tissue biopsy distinguishes it from female pattern hair loss⁵. If you are not sure what you have, this is exactly the case where it is worth taking a close look rather than guessing.

What are the common causes, and where can you read about each one?

Each cause has a detailed page, and the following list shows you where to go.

• Female pattern hair loss (hereditary). The most common cause of thinning, with a widening part and thinning in the center of the scalp. Details: Female pattern hair loss: diagnosis and treatment and Thinning hair in women.
• Temporary shedding after an event. Illness, surgery, stress or a deficiency: telogen effluvium, hair loss after illness, hair loss from stress.
• Hormonal change. Postpartum hair loss, pregnancy, birth control pills and menopause.
• Iron and the thyroid gland. Low ferritin and hair loss, the thyroid gland and deficiencies and vitamins.
• Medications. Medications that cause hair loss.
• Mechanical causes. Tight hairstyles and extensions: traction alopecia.
• Inflamed scalp. Seborrhea of the scalp and lichen planopilaris.
• Sharply defined round bald patches. Alopecia areata.

What happens at menopause?

At menopause, a drop in the hormone estrogen and a relative rise in androgens change the hair cycle, so thinning becomes more common. A 2025 review describes how the hormonal changes can begin up to ten years before periods stop, and that female pattern hair loss, telogen shedding and other forms of hair loss are documented more frequently in women after menopause². This is not inevitable: the type of hair loss can be identified and a treatment chosen. Details on the page Hair loss at menopause.

Which tests are done?

Tests are chosen according to clinical suspicion, not routinely. A JAAD review on iron deficiency and hair loss notes that blood tests can be used for screening (hemoglobin) and confirmation (ferritin), but that there is currently insufficient evidence for routine iron testing in everyone who is losing hair, or for recommending iron supplements in the absence of anemia, so the decision is made by the doctor according to the clinical picture³. Details on the pages Ferritin and hair loss and The thyroid gland.

Beyond blood tests, a close-up trichoscopic examination shows hair thickness and density, and distinguishes between female pattern hair loss and temporary shedding. More details on the page Hair loss diagnosis.

What helps?

Treatment depends on the cause. In temporary shedding, the cause is treated, and the hair usually comes back. In female pattern hair loss, topical minoxidil is the established local treatment: a Cochrane review included 47 trials (5,290 participants). In a pooled analysis of six of them (mainly 2% minoxidil), 157 of 593 women who used it reported moderate to marked regrowth, compared with 77 of 555 on placebo, and the certainty of the evidence was rated moderate⁴. Details on other options, such as anti-androgen medication and combinations, are in Female pattern hair loss, and on combining treatments at the clinic in PRP for hair.

The key point: the earlier you start, the better the chance of preserving hair. Female pattern hair loss is a slowly progressing process, which means there is time to make the right decision, but it is not advisable to wait for years.

What is checked first?

First you understand why, and then you choose a treatment. Hair loss diagnosis includes a conversation about your history (childbirth, illness, medications, diet), a close-up examination of the scalp, and tests as needed. Conditions that require prompt examination: pain, redness or sores on the scalp, sharply defined round bald patches, sudden heavy shedding, or thinning that progresses quickly.

What's new in research (updated November 2026)

Three publications from the past two years that are relevant to women with hair loss:

• Review of hereditary hair loss in women (2026): A review in the American Journal of Clinical Dermatology notes that hereditary hair loss in women is very common but still underdiagnosed and undertreated, and that the impact on quality of life is sometimes greater than in men. Diagnosis requires distinguishing it from chronic diffuse shedding, diffuse alopecia areata and scarring hair loss, using trichoscopy and density measurements. Topical minoxidil is the only FDA-approved treatment for women, alongside off-label treatments, and according to the review, PRP and light therapy are used mainly as an add-on to medical treatment⁶.
• GLP-1 medications and hair loss (2026): A meta-analysis of nine interventional studies, most of them randomized trials, with more than 4,000 patients found that hair loss is reported more often in people receiving GLP-1 class medications, which are given for weight loss and diabetes, than in those receiving placebo. The association held even when only trials in people with excess weight were examined. A woman who starts such treatment and notices hair loss should mention it when she comes for evaluation⁷.
• The causes of hair loss in women (2025): A review in the Journal of Drugs in Dermatology summarizes the causes of hair loss in women: hormonal changes, inflammation, nutritional deficiencies, aging and oxidative stress. It emphasizes the importance of checking iron, vitamin D and minerals, and recommends avoiding excessive supplement use, especially biotin, which can interfere with laboratory test results. According to the review, the evidence for some herbal supplements is still limited⁸.

These summaries describe the study design and the researchers' conclusions, and are not personal recommendations. A decision about treatment is made only after an examination.

How is this done at Dr. Dana's clinic?

At the clinic of Dr. Dana Buchbut, who has been treating hair loss for 16 years, women, mostly aged 45 and over, come for a computerized trichoscopic examination of the scalp and a conversation about their history, and based on the findings a treatment plan suited to you is built.

The information on this page is general educational information only and is not a substitute for an examination, diagnosis or personal medical advice. A decision about treatment is made only after an examination.