Thyroid, Estrogens and Androgens: The Hormonal Context of Shedding in an Optimization Practice

A practice that runs a hormone optimisation programme and a hair programme is running two literatures that overlap at four points, and a prescriber wants to see all four on one page. Thyroid dysfunction is associated with diffuse shedding in both directions. The estrogen transition at menopause coincides with the onset or acceleration of female pattern hair loss in many women, and the intervention literature on estrogen and hair is thin enough that a 2026 systematic review was needed to untangle it. Androgen exposure, including testosterone given for any reason, can unmask or accelerate pattern hair loss in people who are genetically predisposed, and the hyperandrogenism of polycystic ovary syndrome carries the same signal. None of that makes any hormone a hair intervention, and this article is careful about the difference.

This article sets out what the thyroid literature reports, what the menopause and estrogen literature contains, what the androgen literature reports in people receiving testosterone and in hyperandrogenic states, where the guidelines place the antiandrogen question in women, and what the site does and does not supply. It attributes every finding to the study that reported it, makes no claim about what any hormone does to hair, and states plainly that ExaVeyra does not supply controlled substances. The hormone formulations on the compounded formulary are context for this article, not its subject.

Four dials on one panel: why the hormonal context belongs in a hair series

An analogy that holds for the reading of the panel and not for any mechanism is a mixing desk with four dials, where the hair follicle hears the sum. A prescriber evaluating shedding draws thyroid function, considers the patient’s estrogen status and any hormone therapy, asks about androgen exposure of any kind, and in a woman with irregular cycles considers polycystic ovary syndrome, because the literature associates each of those dials with the follicle and the dermal papilla. Böhm, Stegemann, Paus and colleagues reviewed the endocrine controls of skin ageing, including the follicle, in Endocrine Reviews in 2025, and that review is the reference for how many endocrine inputs the follicle integrates.

The article takes the dials in turn and stays on the association side of each. The intervention side, where it exists, belongs to the finasteride article of this series and to the approved labels, and where it does not exist the article says so.

Thyroid: shedding in both directions, and a receptor that has become a research target

Hussein and colleagues reviewed the impact of thyroid dysfunction on hair disorders in Cureus in 2023 and described diffuse shedding in both hypothyroidism and hyperthyroidism, with changes in the hair cycle and, in some series, in hair texture. That is the reason thyroid function sits on the laboratory panel a prescriber draws for shedding, beside the nutritional cofactors discussed earlier in this series. The compounded formulary lists combined T4 and T3 capsules, and they are prescribed for thyroid reasons by prescribers who manage thyroid disease; the shedding literature is a reason to test, not a reason to prescribe.

A newer thread is mechanistic. Zhi and colleagues reviewed thyroid receptor beta as a research target in androgenetic alopecia in Drug Discovery Today in 2024, describing the receptor’s expression in the follicle and the preclinical rationale for targeting it. It is a drug-discovery review rather than a clinical finding, and it is cited here because it explains why the thyroid axis keeps appearing in follicle biology papers that are otherwise about androgens.

Estrogen and menopause: a strong association and a thin, untangled intervention literature

Gupta and colleagues reviewed menopause and hair loss in women in Maturitas in 2025, describing the hormonal transition, the onset or acceleration of female pattern hair loss around it, and the shift in the estrogen-to-androgen balance that the literature associates with the change. Lee, Krishnegowda and Miteva reviewed hormone replacement therapy and hair for trichologists in Dermatology in 2026, and Fux-Otta and colleagues reviewed the diagnostic evaluation of hyperandrogenism after menopause in Climacteric in 2025, which is the differential a prescriber runs when post-menopausal shedding has a pattern distribution.

The intervention literature is what needed untangling. Farkas and colleagues published a systematic review of estrogen therapy for menopausal hair loss in the Journal of the American Academy of Dermatology in 2026, and its value is in the sorting: systemic hormone therapy given for menopausal symptoms, topical estrogens studied for hair, and the older 17-alpha-estradiol solutions are three different literatures with three different qualities of evidence. Kim and colleagues published a single-centre open-label phase IV study of a topical 17-alpha-estradiol solution in female pattern hair loss in Annals of Dermatology in 2012, and it is cited here as representative of that older topical literature and for its design, which is uncontrolled. No FDA-approved topical estrogen for hair exists. The compounded formulary lists estradiol and combination estrogen creams and progesterone preparations, prescribed for menopausal reasons by prescribers who manage menopause; this article does not connect them to hair, because the literature has not.

Androgens: exposure can unmask pattern loss, and the 2026 trial studied that exact population

The androgen signal in pattern hair loss runs through dihydrotestosterone at the dermal papilla, as the finasteride article of this series sets out, and it follows that raising androgen exposure in a genetically predisposed person can unmask or accelerate the process. Thoreson and colleagues reported in JAMA Dermatology in 2021 on the incidence of androgenetic alopecia among transgender and gender-diverse patients receiving masculinising hormone therapy and the factors associated with it, which is the cleanest observational literature on androgen exposure and pattern loss because the exposure is defined and dated.

That population is also where the newest trial sits. Tang and colleagues published a randomised controlled trial in the Journal of the American Academy of Dermatology in 2026 of sublingual minoxidil in transgender people receiving testosterone who had developed androgenetic alopecia, and it is cited here for its design and its population rather than for its result, because it is a minoxidil trial and minoxidil has its own article. Magkou and colleagues updated the skin manifestations of hyperandrogenism in Hormones in 2026, and Motafeghi and colleagues described androgenetic alopecia in polycystic ovary syndrome as a cutaneous marker of systemic endocrine and metabolic dysregulation in Endocrine Connections in 2026. For a hormone optimisation practice the reading is direct: androgen exposure of any kind, including testosterone and the anabolic steroids, belongs on the hair history, and ExaVeyra does not supply those substances.

The antiandrogen question in women belongs to the guidelines and the prescriber

Because pattern loss in women runs partly through the same androgen pathway, the literature asks whether antiandrogens have a place, and the answer sits with the guidelines. The European S3 guideline by Kanti and colleagues addresses antiandrogen approaches in women with graded recommendations and specific cautions, and Iamsumang and colleagues reviewed the evidence for finasteride in female pattern hair loss in Drug Design, Development and Therapy in 2020 as an off-label question with a small and mixed literature. The approved oral finasteride label states that the product is not indicated for women and carries a pregnancy contraindication, and the finasteride article of this series reproduces those sections.

Spironolactone, the antiandrogen most discussed in women, is not part of the compounded formulary this series describes and is mentioned here only because a reader of the guidelines will meet it. Which antiandrogen, if any, suits a given woman is a prescribing decision that weighs the guideline, the label and the patient, and this site takes no part in it.

What the formulary lists, and what this article does with it

Every compounded hormone formulation is prepared under section 503A to an individual prescription and has not been evaluated by the FDA for safety, effectiveness or quality, as the FDA’s questions and answers on compounding state. None is FDA-approved for hair. The clinic-launch guide on adding compounded hormones on this site describes what those formulations are for and how they sit beside approved products, and it is the right page for a practice building a hormone programme; this article is the right page for a practice that wants to know why its hair patients keep appearing on its hormone panel.

Closing Observation

The hormonal context of hair shedding is a literature of four associations that a prescriber reads together: thyroid dysfunction in both directions, the estrogen transition at menopause, androgen exposure in predisposed people, and the hyperandrogenism of polycystic ovary syndrome. The intervention literature is thin everywhere except where it belongs to the approved actives, and the one place it was thick enough to be confusing, estrogen and menopausal hair, needed a 2026 systematic review to sort into three separate questions.

What the literature does not support is the shortcut a combined hormone and hair practice is tempted by, in which a hormone prescribed for one reason is quietly credited with a hair outcome for another. A practice that reads the four dials as associations will gather a better hair history, will send its shedding patients to the right laboratory panel, and will be considerably harder to sell a hormone formulation to on the strength of a correlation the literature has been careful not to overstate.