Ozempic, Wegovy, Mounjaro: do they make your hair fall out?
A few months ago, your main opponent was the bathroom scales. The treatment has done its job, your jeans are a little loose… and a new rival has appeared: the shower drain, filling up with hair faster than expected. You type “Ozempic hair loss” into Google and find everything and its opposite: worried forum posts, testimonials pulling in every direction, contradictory advice.
The good news: this hair loss is well known, usually temporary, and its likely cause is understood. As with creatine, accused of making hair fall out, let’s separate fact from fiction: what the prescribing information and the studies say about Ozempic, Wegovy and Mounjaro, why hair falls out, how long it lasts, and what to do without stopping your treatment.
Menu Ozempic and hair loss
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Ozempic, Wegovy, Mounjaro: which medicines are we talking about?
Ozempic, Wegovy and Mounjaro have one thing in common: they are prescription-only injectable treatments from the family of GLP-1 analogues (also called GLP-1 receptor agonists). They mimic a natural hormone involved in controlling blood sugar and appetite. Yet each one has its own use:
- Ozempic (semaglutide) is authorised for type 2 diabetes. Its official European product information, the summary of product characteristics (SmPC) written for healthcare professionals, does not provide for its use in weight loss.
- Wegovy contains the same molecule, but it is authorised for weight management: in adults with a BMI of at least 30, or 27 with a weight-related condition, according to Wegovy’s European product information.
- Mounjaro (tirzepatide) also mimics a second hormone, GIP. In Europe, it is authorised for both type 2 diabetes and weight management. In the United States, its weight-loss version is called Zepbound.
Their most visible effect is simple: they reduce appetite. Semaglutide reduces the feeling of hunger, as Wegovy’s product information sums it up. You eat less, you lose weight… and that is exactly where your hair can take a hit.
Ozempic and hair loss: a recognised side effect?
Yes for Wegovy and Mounjaro, but it only affects a minority of patients. For Ozempic, only the US prescribing information mentions it, without giving a frequency. So hair loss does appear in the official documents, though not for every product, and with modest figures. To read them properly, you need to compare them with placebo: in these trials, even patients who were not receiving any active medicine reported hair loss.
| Medicine | Hair loss on treatment | On placebo |
|---|---|---|
| Wegovy (US prescribing information, adults) | 3% | 1% |
| Wegovy (EU SmPC) | 2.5% | 1.0% |
| Wegovy 7.2 mg (EU SmPC) | 5.3% | 1.0% |
| Tirzepatide, Zepbound (US prescribing information) | 4–5% depending on dose | 1% |
| Mounjaro (EU SmPC) | “common” (1–10%) | not specified |
| Ozempic (EU SmPC) | not mentioned | not specified |
What should you take from these figures? First, that hair loss affects only a small proportion of patients. On Wegovy, the trials summarised in the US prescribing information recorded it in about 3 patients in 100, compared with 1 in 100 on placebo. According to the European product information, it is usually mild, and most patients recovered while continuing their treatment.
Second, that it goes hand in hand with weight loss: according to Wegovy’s European product information, it is more common in people who lose more than 20% of their body weight. The US prescribing information for tirzepatide makes the same link and reveals a striking detail: women are far more affected than men, at 7.1% compared with 0.5%. Yet no treated patient left the trial because of their hair.
For Mounjaro, the European product information lists hair loss among its “common” effects and specifies that it mainly affects people who are overweight or obese. As for Ozempic, prescribed for diabetes, its European product information does not mention it. In the United States, the prescribing information for Ozempic and Mounjaro lists alopecia, in other words hair loss, among the effects reported after the medicines came onto the market, without being able to give a frequency.
One limitation to bear in mind: these trials were designed to measure weight loss or blood sugar, not the condition of the hair, and they do not say what type of hair loss is involved.
What do recent studies (2024–2026) show?
Since Ozempic, Wegovy and Mounjaro became widespread, researchers have looked closely at the question. Their results broadly point the same way: slightly more hair loss on treatment, with a risk that remains low wherever it could be quantified.
In July 2026, a review of nine studies, including seven randomised clinical trials, found hair loss in about 4 in 100 treated patients, a risk roughly three times higher than on placebo. This “three times higher” figure, however, rests on few studies and remains imprecise.
The same month, a study published in The BMJ, one of the leading medical journals, analysed the medical records of tens of thousands of American adults with type 2 diabetes. Compared with patients on other diabetes medicines, those taking a GLP-1 analogue lost their hair slightly more often: 2 to 3 extra cases per 1,000 patients followed for a year. In other words, the extra risk remains small. This study shows an association, not proof of cause and effect; it says nothing about how long the hair loss lasts or how severe it is, and it only concerns people with diabetes.
Other research opens up a more surprising line of inquiry. Comparing the records of more than a million American patients, researchers found that in the year after starting semaglutide or tirzepatide there were more cases of telogen effluvium and alopecia areata, and almost twice as many diagnoses of hereditary baldness, as with metformin, another diabetes medicine. In their view, weight loss may not explain everything. Caution is needed, though: the study is retrospective, patients on metformin are not necessarily comparable, and the diagnoses come from computer codes, with no examination of the scalp.
Reports received by the US medicines regulator, the FDA, point the same way. An analysis of ten years of reports singles out semaglutide and tirzepatide, and more than three out of four reports concern women. These spontaneous reports say neither how many patients are affected nor whether the medicine is to blame, and media coverage of the subject can increase their number.
In September 2026, researchers at New York University added another piece to the puzzle. By studying the genes of more than 200,000 men, they found a link between the GLP-1 receptor, the target of these medicines, and baldness: in men who were already predisposed, higher activity of this receptor appeared to go hand in hand with a 7% higher risk of baldness. So hair loss may not come solely from rapid weight loss, at least in these men. This genetic study involved neither treated patients nor women: it still needs to be confirmed.
A twist in the news: Novo Nordisk, the maker of Ozempic and Wegovy, is also interested in hair loss, but as a condition to be treated. Its chief scientific officer sees a clear opportunity there for the group’s future medicines. No trial or timetable has been announced.
Why does Ozempic make you lose hair? The telogen effluvium explanation
The most likely explanation for hair loss on Ozempic, Wegovy or Mounjaro has a name: telogen effluvium. Behind this technical term lies a very ordinary phenomenon. Our hairs do not all grow at the same time: each one alternates between a long growth phase and a resting phase, called telogen, at the end of which it falls out. After a shock to the body, such as childbirth, a high fever, an operation… or significant weight loss, many hairs switch into this resting phase at the same time, then fall out a few months later, explains DermNet.
It is the same mechanism as in stress-related hair loss. The American Academy of Dermatology even lists, among the triggers, losing 20 pounds or more, about 9 kg.
Hair loss after weight loss: a well-known pattern
On Ozempic as on Mounjaro, two phenomena probably add up. First, there is the weight loss itself, which the prescribing information links to hair loss. Then there is reduced intake: when appetite drops (a common effect of Mounjaro, according to Vidal, the French medicines reference), you eat less, and sometimes not enough of certain nutrients. The ANSM, France’s medicines agency, points out that “rapid and significant weight loss can lead to various deficiencies”, and its monitoring report notes a potential signal of iron and vitamin B1 deficiencies, as well as muscle wasting.
This is the most likely explanation, though not necessarily the only one: the BMJ study also mentions hormonal changes.
The phenomenon is nothing new. After weight-loss surgery, which also makes the kilos melt away very quickly, more than one patient in two loses hair: 57% according to a review of 18 studies. Younger patients and those who lack zinc, folic acid or iron are the most at risk. The situations differ, but the parallel is telling: major weight loss and deficiencies often go hand in hand with hair loss.
Telogen effluvium: how long does the hair loss last?
It’s the question everyone asks, and the answer is fairly reassuring:
- the shedding starts usually 2 to 4 months after the trigger, here the period of weight loss, according to DermNet;
- the hair grows back: density usually returns within 6 to 9 months, according to the American Academy of Dermatology and DermNet, and often without stopping treatment, notes Wegovy’s European product information.
If the hair loss goes on, it may be chronic effluvium: in that case, see a doctor.
In France in 2026: reimbursement and warnings
Faced with the craze, the rules have changed. Ozempic remains reserved for type 2 diabetes. Since 1 February 2025, reimbursement of Ozempic, like that of the other GLP-1 analogues, has required supporting documentation from the prescribing doctor: the French national health insurance introduced this in response to “massive misuse” fuelled by social media.
Wegovy and Mounjaro have been reimbursed at 65% since 15 June 2026, but not for everyone. You must be an adult and have a BMI of at least 40, or 35 with a weight-related condition, after nutritional care has proved insufficient (less than 5% of body weight lost in six months). The first prescription must come from a doctor working in a specialist obesity centre, a university hospital or a medical and rehabilitation care facility, or from an endocrinologist working with an obesity centre, explains Service-public.fr. Without reimbursement, any doctor has been able to prescribe them since 23 June 2025, according to the ANSM.
Finally, two warnings. These medicines must not be used to lose weight for cosmetic reasons, the ANSM reminds us. And they can only be bought from a pharmacy, on prescription: selling them online is illegal in France, and patches sold online as GLP-1 analogues did not even contain any.
Hair loss on Ozempic, Wegovy or Mounjaro: what should you do?
Don’t stop your treatment without your doctor
The first reflex with this side effect: don’t decide anything on your own in front of the mirror. The hair loss is usually temporary, and a researcher at the University of Cambridge points out that this relatively small risk must be weighed against the major, well-established benefits of these treatments, which probably outweigh it for many patients. Stopping, adjusting or continuing: it’s a decision to make with your doctor.
Have a blood test with your doctor
As deficiencies can contribute to hair loss on Ozempic or Mounjaro, a check-up helps you see things clearly. The care pathway drawn up by French nutrition societies and specialist obesity centres, and relayed by the ANSM in February 2026, provides for a blood test at the start of treatment, including ferritin, which reflects iron stores, and vitamins B9 and B12. It also lists “excessive hair loss” among the signs of iron, zinc or vitamin deficiency. A literature review published in April 2026 recommends adding thyroid function and vitamin D. If severe fatigue comes with the hair loss, tell your doctor: it helps guide the tests.
It’s up to your doctor to choose the tests and correct any deficiency. It is better not to take one anti-hair-loss supplement after another at random: they are no substitute for a diagnosis.
Get enough protein on your plate
With less appetite, portions shrink… and so does protein. Yet hair is mainly made of keratin, a protein. The same care pathway asks for your diet to cover “the minimum recommended intake (60 g/day)” of protein; for a healthy adult, Anses, France’s food safety agency, uses a reference of 0.83 g per kilo of body weight per day. Eggs, fish, meat, dairy, pulses: a dietitian can help you fit them into smaller meals. The care pathway also recommends staying active, with endurance and muscle-strengthening exercise.
Pamper your hair
While waiting for regrowth, DermNet advises treating your hair gently. In practice: detangle without pulling, choose loose hairstyles, and use a mild shampoo that is gentle on the scalp, such as the GrowthFactor shampoo, which we also recommend to our patients after a transplant. And don’t panic at the sight of the shower drain: in telogen effluvium, the hairs that fall out were already at the end of their cycle, and washing simply carries them away.
Our tip: GrowthFactor shampoo
A gentle, paraben-free formula, also designed for the scalp after a transplant.
When should you see a dermatologist?
Some signs don’t fit with simple effluvium and call for a specialist opinion:
- the hair loss forms round or oval patches: this is typical of alopecia areata, an autoimmune disease;
- it lasts more than 6 months or creates a thinning pattern (receding temples, crown): the April 2026 review recommends a specialist opinion beyond 6 to 9 months, or as soon as the hair loss takes on a typical pattern;
- your scalp is painful or itchy, which does not usually happen with simple hair loss: some forms of alopecia, known as scarring alopecia, are permanent.
To find out more, discover the causes of hair loss.
And where does a hair transplant fit in?
Let’s be clear: a transplant does not treat telogen effluvium. The hair usually grows back on its own once the trigger has passed, and the April 2026 review finds no solid evidence that these treatments cause lasting damage to the follicles. So there is nothing to “replace”.
The situation changes if androgenetic alopecia, in other words hereditary baldness, is discovered. It can be diagnosed during or after treatment: the 2026 studies record more cases, without saying whether the treatment triggers it or simply reveals it. A transplant then becomes an option again, once your weight and the hair loss have stabilised. Waiting has another advantage: you won’t confuse effluvium with “shock loss”, the temporary shedding of transplanted hair that is common between the 1st and 3rd month after the procedure.
If you are on treatment, mention it at the diagnosis stage. These medicines slow down stomach emptying, and Wegovy’s US prescribing information mentions rare cases of aspiration (stomach contents passing into the lungs) during general anaesthesia or deep sedation. Your doctor and Klineva’s medical team will decide on the right course of action before the procedure.
Next comes the choice of technique, Sapphire FUE transplant or DHI method, followed by post-transplant care with PRP and light therapy. To find out whether your hair loss calls for a transplant, request a free diagnosis from your photos.
Some Klineva hair transplant results
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Our techniques: Sapphire FUE · DHI method · No-shave · Beard transplant · Women
In brief: what to remember about Ozempic and hair loss
✅ A recognised side effect that affects only a minority of patients: about 3 in 100 patients lose hair on Wegovy, 4 to 5 in 100 on tirzepatide, compared with 1 in 100 on placebo.
✅ A likely cause: telogen effluvium, linked to weight loss and reduced intake.
✅ A genetic lead: in men predisposed to baldness, a September 2026 study also suggests a biological link between the action of these medicines and baldness.
✅ Temporary hair loss: it starts 2 to 4 months after the trigger, and the hair usually grows back within 6 to 9 months.
✅ The right reflexes: don’t stop on your own, get checked by your doctor, eat enough protein, treat your hair gently, and see a dermatologist if there are patches or the hair loss goes on.
✅ Hair transplant: pointless against effluvium; worth considering if androgenetic alopecia is confirmed, once your weight and the hair loss have stabilised.
Your questions about Ozempic, Wegovy, Mounjaro and hair loss
Does hair grow back after hair loss on Ozempic or Wegovy?
Usually, yes. Telogen effluvium is temporary: density generally returns within 6 to 9 months, often without stopping treatment. If the hair loss lasts more than 6 months or forms patches, see a dermatologist.
How soon does hair loss start on Ozempic?
Usually 2 to 4 months after the trigger, that is, the period of weight loss, not the start of treatment. So the hair loss can come as a surprise when the treatment has been well tolerated for several months. In most cases, it then passes.
Should you stop Ozempic if you are losing hair?
No, not on your own. Your doctor will check your diet and blood test results before deciding whether anything needs adjusting. In fact, in the two tirzepatide obesity trials pooled in Zepbound’s US prescribing information, no treated patient stopped treatment because of their hair.
Does Mounjaro cause more hair loss than Wegovy?
The data do not allow us to say so. The US prescribing information gives 4–5% for tirzepatide versus 3% for semaglutide 2.4 mg, but in different trials, which are therefore hard to compare. Semaglutide also reaches 5.3% at 7.2 mg, and hair loss is more common in those who lose the most weight.
Can Ozempic or Wegovy speed up hereditary baldness?
It’s possible, but not proven. A genetic study from New York University (September 2026) links higher activity of the GLP-1 receptor, the target of these medicines, to a 7% higher risk of baldness in men who are already predisposed. It involved neither treated patients nor women. If your hair loss looks like baldness (receding temples, crown), talk to your doctor or a dermatologist.
Can you use minoxidil while on Ozempic, Wegovy or Mounjaro?
Minoxidil is a standard treatment for androgenetic alopecia. With effluvium, after which the hair usually grows back on its own, the question is less relevant. A 2026 review considers that topical minoxidil may be appropriate if the hair loss takes on the appearance of androgenetic alopecia: ask your doctor or a dermatologist for advice.
Can you have a hair transplant while on Ozempic, Wegovy or Mounjaro?
Not for effluvium, after which the hair usually grows back on its own. If androgenetic alopecia is confirmed, wait until your weight and the hair loss have stabilised, and tell the medical team about your treatment, as it slows stomach emptying.