Hair loss in women: why we're seeing so much more of it in practice

A few years ago, hair shedding was something I'd mostly see alongside postpartum recovery or a known thyroid issue or even post COVID hair loss which affected many women. Lately, it's one of the most common things women bring up in an intake appointment often as an afterthought, almost embarrassed, after we've already covered fatigue, sleep, and mood. "Oh, also, my hair has been coming out in handfuls." It's not in your head, and it's not just you. There are a few real, identifiable reasons it's showing up more often right now.

It's usually one of two different things

Hair loss in women almost always falls into one of two categories, and they need different workups.

Telogen effluvium is diffuse, whole-scalp shedding that shows up two to three months after some kind of physiological stressor illness, surgery, a crash diet, childbirth, a major stressor, or rapid weight loss. It's triggered when a higher-than-normal percentage of hair follicles get pushed prematurely from the active growth phase into the resting phase. A few months later, all those resting hairs shed at once. It's frightening to experience, but it's reversible once the trigger resolves.

Female pattern hair loss (also called androgenetic alopecia) is different: gradual thinning, usually concentrated at the part line and crown, with the frontal hairline staying intact. It's driven by genetic sensitivity to androgens at the follicle level and tends to progress slowly over years rather than showing up as sudden shedding.

Telling these apart matters, because the workup and the timeline for improvement are different for each.

Why I think we're seeing more of it right now

GLP-1 medications and rapid weight loss are a real, documented contributor. This is one of the bigger shifts I've noticed clinically, and the research backs it up. A 2026 systematic review of GLP-1 receptor agonists and hair loss found that semaglutide and tirzepatide had the strongest associations with hair shedding among this drug class, with telogen effluvium as the most common mechanism and that women appeared to be disproportionately affected. Novo Nordisk's own clinical trial data for Wegovy reported hair loss in 2.5% of treated patients versus 1.0% on placebo, with the effect more common in people losing 20% or more of their body weight. The mechanism isn't usually the drug itself it's the speed and scale of the weight loss acting as a physiological stressor, often compounded by lower protein and micronutrient intake from a smaller appetite.

Iron and thyroid status come up constantly. A 2025 case-control study comparing 100 women with hair loss to 100 age-matched controls found significantly lower haemoglobin, iron, and ferritin levels in the hair loss group. That said, the research here is genuinely mixed some studies show a clear ferritin link, others don't, which is exactly why testing matters more than assuming.

Chronic stress and under-eating are doing more damage than people realize. Restrictive dieting, whether intentional or a side effect of appetite-suppressing medication, is itself a stressor capable of triggering telogen effluvium independent of any specific drug.

PCOS and metabolic factors show up more than expected. A 2024 case-control study found a higher prevalence of metabolic syndrome among premenopausal women with female pattern hair loss compared to controls, and a 2025 systematic review confirmed a meaningful bidirectional relationship between PCOS and pattern hair loss.

What I actually test for

When a patient comes in with new or worsening hair shedding, I'm not reaching for biotin first. I'm running:

• Complete blood count and iron studies, including serum ferritin specifically (not just haemoglobin)

• Full thyroid panel  TSH at minimum, often free T3, free T4, and thyroid antibodies depending on history

• Vitamin D and zinc, both of which show up repeatedly in the research as relevant to follicle cycling

• A detailed history of the past 3 to 6 months illness, major stress, medication changes, weight changes, postpartum timing since telogen effluvium has a built-in lag

If there's any sign of androgen excess irregular periods, new acne, hirsutism I'll also look at testosterone and related markers, since that points toward a pattern-loss or PCOS-related process rather than a pure stress response.

What this could look like in practice

For a patient who started a GLP-1 medication six months ago and noticed shedding starting around month three or four, the conversation usually isn't "stop the medication" it's making sure protein intake, iron, vitamin D, and B12 are actually adequate for the new, smaller amount of food being eaten, and giving the hair cycle the 6 to 12 months it typically needs to fully recover once the underlying stressor is addressed.

For a patient with gradual, pattern-style thinning and a family history of it, the conversation is different that's a longer-term management situation, and I'll often coordinate with a dermatologist on the medical side while supporting the metabolic and inflammatory factors within my scope.

Frequently asked questions

Will my hair grow back? If it's telogen effluvium, yes, in the large majority of cases, once the trigger is identified and addressed though regrowth is genuinely slow, typically 6 to 12 months for a full cycle. Pattern hair loss is more about slowing progression and supporting follicle health than full regrowth.

Does biotin actually help? Only if you're deficient, which is uncommon outside of specific situations like pregnancy or certain malabsorption conditions. Biotin gets recommended reflexively far more often than the evidence supports it for general hair shedding.

Should I stop my GLP-1 medication if I'm losing hair? That's a conversation to have with the prescribing provider, not a decision to make alone the hair loss is usually a sign that nutritional support needs attention, not necessarily a reason to discontinue the medication.

How long after a stressful event does hair loss typically start? Classically 2 to 3 months, which is part of why the connection is often missed by the time the shedding starts, people have usually stopped connecting it to whatever happened months earlier.

This article is for educational purposes and is not medical advice. If you're experiencing hair loss, please consult a qualified healthcare provider for proper testing and diagnosis, especially before stopping or changing any prescribed medication.

Noticing more shedding than usual? Book a free 15-minute discovery call to talk about what might be behind it and whether working together is the right fit. Book here