It started as a horror movie scene. I am showering with upbeat music in the background and suddenly start to notice that an abnormal amount of hair is dangling in my hand. “Suspense music plays” — reads the captions. Once I am all dressed up and with my hair drying, I move on with my day. But a few weeks later I sat at a salon ready to get my annual trim, when the hairstylist said “Wow! Your hair falls out a lot.” There was no pushing it aside or denying it anymore. While some hair loss can be normal, I knew that the amounts I was facing merited some research; because more often than not, your hair won’t fall out on its own. Something is prompting the hair loss and it is worth finding out what that is.
There’s a particular kind of grief that comes with losing your hair. It’s private and because it tends to happen gradually, it is easy to dismiss until one day you simply can’t. Women lose between 50 and 100 hairs per day under normal circumstances [1]. When that number climbs significantly, or when regrowth slows and thinning patches appear along the crown or temples, something deeper is usually going on. And in women of reproductive age or nearing menopause, that something is very often hormonal.
Hormones govern far more of our biology than most of us are taught. They regulate our cycles, our moods, our metabolism, our skin—and yes, our hair growth. The hair follicle is exquisitely sensitive to hormonal fluctuations, and when your endocrine system falls out of balance, your scalp is frequently the first place the evidence appears. Understanding the connection isn’t just about vanity. It’s about learning to read your own body.
The hair follicle is exquisitely sensitive to hormonal fluctuations, and when your endocrine system falls out of balance, your scalp is frequently the first place the evidence appears. Understanding the connection isn’t just about vanity. It’s about learning to read your own body.
The androgen problem
To understand hormonal hair loss, you first need to understand androgens. These are the so-called “male hormones” which include testostérone, DHEA, and their derivatives. Women produce these hormones in smaller but critically important amounts. One androgen in particular, dihydrotestosterone (DHT), is largely responsible for a pattern of hair thinning called androgenetic alopecia, or female-pattern hair loss [2].
DHT is formed when an enzyme called 5-alpha reductase converts testosterone. In genetically susceptible individuals, DHT binds to receptors in the hair follicle and causes it to miniaturize. As a consequence of this, it produit finer, shorter strands until the follicle eventually stops producing hair altogether [3]. The result is the characteristic widening part, thinning crown, and temple recession that many women notice as they age. Androgenetic alopecia affecte roughly 40% of women by age 50, but it can appear much earlier, especially when underlying hormonal conditions are in play [4].
PMOS: The most common culprit
If there is one condition that deserves a serious spotlight when it comes to hormonal hair loss, it’s Polyendocrine Metabolic Ovarian Syndrome (PMOS). Formerly known as PCOS, PMOS affects an estimated 1 in 10 women of reproductive age, making it one of the most common endocrine disorders in women—yet one of the most underdiagnosed [5]. Women with PMOS typically have elevated androgen levels, which is why hair loss is one of its hallmark symptoms alongside irregular cycles, acne, and excess facial or body hair (a pattern known as hirsutism) [6].
Women with PMOS typically have elevated androgen levels, which is why hair loss is one of its hallmark symptoms alongside irregular cycles, acne, and excess facial or body hair (a pattern known as hirsutism).
The cruel irony of PMOS-related hair loss is that it often mimics the same DHT-driven mechanism as androgenetic alopecia, but at a younger age and in the context of a broader hormonal imbalance that can affect fertility and metabolic health. Women with PMOS who are also insulin resistant (which is common) may find their androgen levels further elevated, since insulin stimulates ovarian androgen production [7]. When cells stop responding efficiently to insulin, the pancreas compensates by pumping out more of it to keep blood sugar in check. This results in chronically elevated insulin in the bloodstream, which opens the gate to multiple health struggles. This is why addressing blood sugar and insulin sensitivity is often a meaningful piece of the hair loss puzzle for women with PMOS.
Troubles de la thyroïde
Dysfonctionnement de la thyroïde is another frequent driver of hair loss that goes far too long without a diagnosis. Both hypothyroidism (an underactive thyroid) and hyperthyroidism (an overactive thyroid) can cause diffuse shedding across the scalp [8]. The thyroid hormones T3 and T4 are essential for regulating the hair follicle cycle. When they’re too low or too high, follicles shift prematurely into the resting (telogen) phase, leading to widespread hair loss that can feel sudden and alarming [9].
Women are significantly more likely than men to develop thyroid disorders, particularly Thyroïdite de Hashimoto—an autoimmune condition in which the immune system attacks the thyroid gland. Because many thyroid symptoms (fatigue, weight changes, mood shifts) overlap with other common complaints, it can take years to receive a proper diagnosis. If you’re experiencing diffuse shedding alongside exhaustion, cold intolerance, or brain fog, a full thyroid panel (including TSH, free T3, free T4, and thyroid antibodies) is absolutely worth requesting.
Postpartum hair loss
If you’ve ever grown a lush, full head of hair during pregnancy only to watch it fall out in handfuls three months after giving birth, you’ve experienced postpartum telogen effluvium. During pregnancy, elevated estrogen prolongs the growth phase of the hair cycle, reducing normal daily shedding [10]. After delivery, estrogen drops sharply, and all those follicles that stayed in the growth phase shift into the resting phase simultaneously. This produces a wave of shedding that typically peaks around three to four months postpartum [11].
This type of hair loss is usually temporary and resolves on its own within six to twelve months, though it can be distressing, particularly when compounded by postpartum depletion. Adequate iron, zinc, and protein intake are especially important during recovery, as les déficiences nutritionnelles can extend or worsen the shedding phase [12]. (For more on postpartum hair loss, voir cet article de Natural Womanhood.)
The hormonal shifts of perimenopause (the years leading up to the final menstrual period) bring their own form of hair growth disruption. As estrogen and progesterone decline, the relative influence of androgens increases, tipping the hormonal balance in ways that accelerate follicle miniaturization and thinning [13]. For many women, this is the first time hair loss becomes noticeable enough to seek answers.
It is worth knowing that estrogen and progesterone are not simply reproductive hormones. They are also hair-protective hormones. Their decline is not an inevitable slide into loss, but a signal that the body needs support. Approaches that address the root hormonal imbalance including nutrition, stress management, targeted supplementation, and in some cases bioidentical hormone replacement therapy, have been shown to make a meaningful difference [14].
Ce que vous pouvez faire
The most important first step toward addressing hormonal hair loss is getting a thorough workup. Ask for a complete hormone panel that includes testosterone (total and free), DHEA-S, LH, FSH, estrogen, progesterone, and insulin levels, in addition to a full thyroid panel and iron studies including ferritin. Hair loss in women is rarely a single-cause issue; it is usually a convergence of factors, and treating it well requires understanding the full picture. You might consider finding an endocrinologist able to work with you in reading your labs and discovering the source of your hair loss.
Hair loss in women is rarely a single-cause issue; it is usually a convergence of factors, and treating it well requires understanding the full picture.
Beyond labs: support your follicles nutritionally with iron-rich foods, adequate protein (at minimum 1g per kg of body weight), omega-3 fatty acids, biotin, zinc, and vitamin D. Depending on your labs, you may want to consider supplements, but before you look into it, make sure that your diet is filled with the nutrients mentioned above. Also, reduce physiological stressors where possible. Chronic stress elevates cortisol, which in turn suppresses sex hormones and disrupts the hair cycle [15]. Stress relieving exercise such as going for walks or dancing can also help.
Le bilan
Hair loss is a symptom. If you’re noticing above average amounts of hair loss, don’t ignore it. Consult with a physician to find the underlying cause. Loss of hair doesn’t have to be a life sentence. Plus, when you pay attention to this signal that something deeper is going on, you have the opportunity to address health issues whether shedding your tresses is due to a thyroid disorder, PMOS, perimenopause, or hormonal imbalance.
Références
[1] American Academy of Dermatology Association. (2023). Hair loss: Who gets and causes. AAD.org.
[2] Trüeb, R. M. (2002). Molecular mechanisms of androgenetic alopecia. Experimental Gerontology, 37(8–9), 981–990.
[3] Ramos PM, Miot HA. Female Pattern Hair Loss: a clinical and pathophysiological review. An Bras Dermatol. 2015 Jul-Aug;90(4):529-43. doi: 10.1590/abd1806-4841.20153370. PMID: 26375223; PMCID: PMC4560543.
[4] Blume-Peytavi, U., Blumeyer, A., Tosti, A., et al. (2011). S1 guideline for diagnostic evaluation in androgenetic alopecia in men, women and adolescents. British Journal of Dermatology, 164(1), 5–15.
[5] Bozdag, G., Mumusoglu, S., Zengin, D., Karabulut, E., & Yildiz, B. O. (2016). The prevalence and phenotypic features of polycystic ovary syndrome: A systematic review and meta-analysis. Reproduction humaine, 31(12), 2841–2855.
[6] Lizneva, D., Suturina, L., Walker, W., Brakta, S., Gavrilova-Jordan, L., & Azziz, R. (2016). Criteria, prevalence, and phenotypes of polycystic ovary syndrome. Fertilité et stérilité, 106(1), 6–15.
[7] Dunaif, A. (1997). Insulin resistance and the polycystic ovary syndrome: Mechanism and implications for pathogenesis. Revues endocriniennes, 18(6), 774–800.
Références suite
[8] Hussein RS, Atia T, Bin Dayel S. Impact of Thyroid Dysfunction on Hair Disorders. Cureus. 2023 Aug 10;15(8):e43266. doi: 10.7759/cureus.43266. PMID: 37692605; PMCID: PMC10492440.
[9] Contreras-Jurado, C., Lorz, C., García-Serrano, L., et al. (2015). Thyroid hormone signaling controls hair follicle stem cell function. Molecular Biology of the Cell, 26(7), 1263–1272.
[10] Lynfield, Y. L. (1960). Effect of pregnancy on the human hair cycle. Journal of Investigative Dermatology, 35(6), 323–327.
[11] Grover, C., & Khurana, A. (2013). Telogen effluvium. Indian Journal of Dermatology, Venereology and Leprology, 79(5), 591–603.
[12] Almohanna, H. M., Ahmed, A. A., Tsatalis, J. P., & Tosti, A. (2019). The role of vitamins and minerals in hair loss: A review. Dermatology and Therapy, 9(1), 51–70.
[13] Faubion, S. S., Larkin, L. C., Stuenkel, C. A., et al. (2018). Management of genitourinary syndrome of menopause in women with or at high risk for breast cancer: Consensus recommendations. Ménopause, 25(6), 596–608.
[14] Goluch-Koniuszy, Z. S. (2016). Nutrition of women with hair loss problem during the period of menopause. Menopause Review, 15(1), 56–61.
[15] Thom, E. (2016). Stress and the hair growth cycle: Cortisol-induced hair follicle stem cell dysfunction. Journal of Drugs in Dermatology, 15(8), 1001–1004.
