Hormonal hair loss: understanding the link and choosing the right tests

Follicle sensitivity is different from a blood hormone level

Androgens are present in both women and men. Testosterone can be converted into DHT, a hormone involved in the gradual thinning of susceptible hairs. Affected follicles produce shorter, finer shafts over successive cycles, a process called miniaturisation.

The strength of that local response cannot be read directly from a blood result. A concentration within the normal range may act on sensitive follicles, while a thinner head of hair cannot reveal someone’s testosterone level. Identifying androgenetic alopecia starts with the history and examination of the hair.

The contribution of androgens is less consistent in female pattern hair loss than in male pattern baldness. Fabbrocini and colleagues describe several possible mechanisms, including cases in which androgen concentrations are not elevated. Treating every widening parting as evidence of “too much male hormone” can therefore lead to tests or medication that do not address the actual problem.

After pregnancy: timing helps, but does not establish the diagnosis

Pregnancy and the period after delivery change the hormonal environment and hair renewal. Diffuse shedding may become noticeable around two to three months after birth, as more hairs reach the end of their cycle. That interval can fit telogen effluvium, although the circumstances alone cannot confirm it.

Samrao and Mirmirani reported three cases in which postpartum shedding brought an underlying traction alopecia to attention. This small series highlights the value of examining loss that persists or becomes localised. It does not establish that one hormone, such as progesterone, accounts for every postpartum hair change.

Tell your clinician when you gave birth, about changes in hairstyles, any substantial bleeding and other unusual symptoms. A patch that remains bare or shedding that develops unexpectedly deserves reassessment. There is no need to end breastfeeding or seek hormone treatment in an attempt to answer this question yourself.

Around menopause, different processes can overlap

Hormonal changes at this stage form part of a broader picture that includes ageing hair, inherited susceptibility and possible accompanying illnesses. Gradually reduced volume may become more apparent without one specific deficiency explaining everything. The appearance of the hair is therefore insufficient to decide that oestrogen should be prescribed.

A wider parting, recently increased shedding and a retreating frontal hairline do not necessarily have the same diagnosis. The scalp needs examination, particularly when discomfort, redness or clearly defined bare areas occur too. Our article on postmenopausal hair loss explores these distinctions and the care options in more detail.

If you already use hormone replacement therapy, give your GP its name and the dates of any changes. Decisions about adjusting it depend on your health and the reasons it was prescribed. A concern about hair alone is not a reason to start HRT, increase it or discontinue it yourself.

Thyroid assessment includes symptoms beyond the hair

An underactive thyroid can cause tiredness, sensitivity to cold, constipation and dry hair or shedding. An overactive thyroid may instead cause difficulty tolerating heat, palpitations, trembling or weight loss, sometimes alongside thinning hair. These descriptions can guide a consultation; they cannot identify the condition from a photograph.

Your GP considers the whole set of symptoms, your medical background and current medication. Thyroid blood tests, including TSH and, depending on the circumstances, T4, may be needed. Hair loss with fatigue can also have other explanations that should not be dismissed too quickly.

When thyroid disease is diagnosed, managing it addresses your wider health needs first. Neither treatment nor monitoring should be adjusted according to the amount of hair in the shower. Disappointing hair progress calls for another medical discussion, rather than changing a prescription or adding iodine yourself.

When should androgen excess or PCOS be investigated?

In women, irregular periods, new or pronounced facial or body hair growth, and substantial acne may support a hormonal investigation. These features are more informative when their timing is established and they are considered together. Polycystic ovary syndrome, or PCOS, is one possible diagnosis, rather than the only explanation.

The 2023 international guideline states that female pattern hair loss or acne occurring alone, without excess hair growth, are relatively weak indicators of raised androgen levels. Shedding therefore cannot establish PCOS by itself. Diagnosis uses clinical criteria and excludes other causes, with particular rules applying during adolescence.

Rapidly developing or markedly worsening features of androgen excess need medical assessment rather than waiting for a cosmetic appointment. The clinician considers changes in body hair and other physical features. The investigation seeks a specific explanation instead of automatically attributing these signs to stress or a normal life stage.

Targeted tests are more useful than checking every hormone

An appointment starts by describing the onset, pace and distribution of hair loss, including any earlier episodes. The clinician also examines the scalp and variation in hair thickness, sometimes using magnification. Blood tests cannot replace this assessment of the hair disorder itself.

Investigations then address a clinical possibility. Thyroid testing answers a different question from androgen measurements, and not everyone needs both. Fabbrocini and colleagues explain that laboratory investigations are rarely undertaken for typical female pattern hair loss when there are no features suggesting androgen excess. The question is whether a result would change the next clinical decision, rather than whether the test is available.

Existing medication can make results harder to interpret. For example, the combined contraceptive pill changes androgen concentrations and their transport proteins, a difficulty recognised in the PCOS guideline. If testing is essential, the professional arranges the conditions and continued contraception: do not suspend your pill to prepare your own hormone assessment.

Bring prescriptions, earlier results and details of any supplements you take. Ask which question each investigation addresses and how the answer would affect care. Reassuring findings may mean continuing the dermatological assessment, rather than repeating hormone measurements in search of one number to explain every symptom.

Treatment choices depend on the cause and the risks

Managing an identified endocrine condition and treating alopecia are not always the same task. When both are present, coordinated care may be appropriate. Your clinician can explain each treatment’s purpose, such as controlling disease, limiting miniaturisation or improving hair coverage, without promising that everything will improve at the same pace.

Minoxidil applied to the scalp may be considered for some forms of pattern hair loss. It does not work by correcting an oestrogen or testosterone blood level. Potential benefit, tolerability and the practical demands of treatment need discussion; tell the prescriber about pregnancy, plans to conceive or breastfeeding before a medicine is chosen.

Antiandrogens require an individual medical decision. In PCOS, the guideline specifically acknowledges the limited evidence for their effect on female pattern hair loss. These medicines can affect fetal development, so considering them requires an explicit discussion of contraception and contraindications.

Oral finasteride used for some cases of male pattern baldness also requires clear information about sexual and psychiatric risks. Some adverse effects can continue after discontinuation, so they must not be described as invariably reversible. The MHRA strengthened its safety advice in May 2026 and reminds patients to read and retain the alert card supplied with their medicine.

For someone taking finasteride for hair loss, developing depression or suicidal thoughts means stopping it and seeking medical help promptly, in line with the safety advice. Sexual difficulties also need discussion with the prescriber. These instructions concern this particular medicine; they are not a reason to stop contraception or thyroid treatment without professional advice.

Monitor your hair without chasing a perfect “balance”

Care is reviewed against changes in the hair, associated symptoms and treatment tolerability. An improved blood result does not mean that hair volume immediately changes. Follow-up also helps identify another cause when only part of the problem gets better. Agree what improvement would mean for you, and when another assessment would be useful if the course is unexpected.

Shampoos, cosmetic products or supplements promoted as “hormone regulating” cannot replace this clinical reasoning. A claim that something is natural says nothing about its effectiveness or possible interactions. Ask what the product is meant to change and what evidence supports its use for your particular diagnosis.

You can also discuss worry about changes in your appearance, even when other people consider them subtle. Preferences matter when deciding whether to use treatment, camouflage or take more time. Our hair transplant guide offers further context for distinguishing medical care from a procedure.

A transplant cannot correct endocrine disease

The label “hormonal hair loss” is not enough to justify surgery. Transplantation relocates follicles but cannot treat thyroid disease or androgen excess. Its suitability depends on the hair diagnosis, expected progression and the hair available in the donor region, among other considerations.

If surgery becomes an option after assessment, discuss its limitations and alternatives with the medical team. Body Expert provides English-speaking support for planning this pathway. Information about a hair transplant in Istanbul explains the steps involved while leaving management of any endocrine condition with the clinician responsible for your care.

Sources

Fabbrocini, G., Cantelli, M., Masarà, A., Annunziata, M. C., Marasca, C., & Cacciapuoti, S. (2018). Female pattern hair loss: A clinical, pathophysiologic, and therapeutic review. International Journal of Women’s Dermatology, 4(4), 203–211. https://doi.org/10.1016/j.ijwd.2018.05.001

Medicines and Healthcare products Regulatory Agency. (2026, May 11). Finasteride and dutasteride: Updated safety warnings for psychiatric side effects and sexual dysfunction. MHRA safety update

NHS. (2025, April 28). Underactive thyroid (hypothyroidism). NHS information on hypothyroidism

NHS. (2023, April 11). Overactive thyroid (hyperthyroidism): Symptoms. NHS information on hyperthyroidism symptoms

Samrao, A., & Mirmirani, P. (2022). Postpartum telogen effluvium unmasking traction alopecia. Skin Appendage Disorders, 8(4), 328–332. https://doi.org/10.1159/000521705

Teede, H. J., Tay, C. T., Laven, J. J. E., Dokras, A., Moran, L. J., Piltonen, T. T., Costello, M. F., Boivin, J., Redman, L. M., Boyle, J. A., Norman, R. J., Mousa, A., & Joham, A. E. (2023). Recommendations from the 2023 international evidence-based guideline for the assessment and management of polycystic ovary syndrome. The Journal of Clinical Endocrinology & Metabolism, 108(10), 2447–2469. https://doi.org/10.1210/clinem/dgad463