Mounjaro Hair Loss: Why It Happens, How Long It Lasts and What I’d Do About It

Last updated: November 2026

A stylist I interviewed a few weeks ago messaged me to say she keeps hearing the same thing in her salon chair. Women losing hair on Ozempic and Mounjaro – and asking if extensions are safe for them.

That’s a horrible place to be.

I’ve had hair loss since I was 19 (androgenic alopecia, the slow genetic kind) and I’ve worn toppers and wigs for over twenty years, so the hair side of this I know. The medical side is your GP’s job, and I’m not going to pretend otherwise. What I can do is go through what the research says and what I’d do about it, then hand over to Kenzie (the stylist) for the extensions question.

Does Mounjaro cause hair loss?

Yes, it can. The UK patient leaflet for Mounjaro now lists hair loss under common side effects, with the note “observed in weight management”. Common there means up to 1 in 10 people.

In SURMOUNT-1, the big trial of tirzepatide for weight loss, around 5% of people taking it reported hair loss, compared with about 1% on the placebo. Wegovy’s trial numbers were lower, around 3% against 1%.

Then in 2026 a study in the BMJ went through the records of around 50,000 adults with type 2 diabetes. People on GLP-1 drugs had a 37% higher risk of hair loss than people on a different kind of diabetes medicine called SGLT-2 inhibitors. The hair loss they saw was the non-scarring type, which is the bit I’d hang on to, because it means the follicles are still there and the hair can grow back.

Quick bit of naming, because it gets confusing. Mounjaro is the brand name for tirzepatide. Ozempic and Wegovy are both semaglutide. They’re all GLP-1 medicines, and Mounjaro works on a second hormone called GIP as well.

Why does it happen?

The BMJ researchers named weight loss and eating fewer calories as the most likely cause, rather than the medicine itself, while saying more research is needed.

Your hair grows in cycles. A big shock to your body, like losing a lot of weight fast or suddenly eating much less, can push loads of hairs into the resting phase at the same time, and a couple of months later they come out together. That’s telogen effluvium. Eating far less can also leave you low in protein, iron, zinc or vitamin D, and your hair needs all of those to keep growing.

So your body is basically putting hair on the back burner while it deals with everything else going on.

When does Mounjaro hair loss start, and how long does it last?

Shedding usually shows up two to four months after the weight starts coming off fast. That delay is why it catches people out. The scale is going the right way and then suddenly your brush looks like it’s grown a pet.

For most people the shed slows down once their weight settles, usually within about six months. Getting it back to how thick it looked before takes longer, since hair only grows about a centimetre a month.

One thing I’d want someone to tell me: a big shed can also show up thinning that was already there. If you had some genetic thinning before you started, a shed can make it really obvious, and that part won’t sort itself out when the weight settles. Worth knowing so your not waiting forever for something that needs treating.

Should you stop Mounjaro because of hair loss?

That one’s for your GP or prescriber, not me. Don’t stop it or change your dose without talking to them first.

Do tell them about your hair though. Especially if it’s coming out in patches, your scalp is sore or red, it’s still heavy after six months, or you feel tired and run down all the time. Ask about blood tests too. Ferritin, which shows your iron stores, vitamin D, B12, folate and thyroid are the usual ones people get checked for hair.

How to stop hair loss on Mounjaro (or at least help it grow back)

You can’t really switch a telogen shed off once it’s started. So I went looking for what doctors and dermatology groups recommend, and most of it comes down to what’s going on inside your body.

Bloods come first. DermNet, a skin site written by New Zealand dermatologists, says to correct any thyroid, iron, B12 or folate problems, and the team behind the BMJ study named low iron, zinc and biotin as things that can upset the hair growth cycle. Fixing a deficiency you actually have can make the shed less severe and help it pass sooner.

Then food, which I know is the hard part when the jab means you’re barely hungry. A 2025 joint advisory from four US obesity and nutrition groups, including the Obesity Medicine Association and the American Society for Nutrition, lists enough protein and strength training as priorities for anyone on a GLP-1. It also says to watch for low iron, B vitamins, calcium and vitamin D when you’re eating less. Hair is made of protein, so ask your prescriber or a dietitian what you should be aiming for.

Faster weight loss is also linked with more shedding, and some prescribers may suggest stepping the dose up more slowly if you’re worried about your hair. That’s their call to make with you, so don’t change your dose on your own.

DermNet also recommends handling your hair gently while it’s fragile. No tight ponytails, and brush from the ends up instead of dragging through from the root.

If it isn’t settling, ask for a referral. The BMJ researchers say dermatology referral may be needed, and the American Academy of Dermatology says that while hair usually gets back to its normal fullness within six to nine months, shedding can drag on if whatever set it off is still going.

Can you get hair extensions while losing hair on Mounjaro?

Kenzie Moon from Wefts + Waves has hereditary hair loss herself and puts extensions in thin hair every week. She’s just written about this exact question, and her answer is sometimes. It depends on how much of your own hair is left to hold the weight.

I sent Kenzie a few extra questions for this post, and here’s what she said.

Her big point is to add less hair, not more. She’d do one lower row instead of two and use lighter K-tip bonds, with only enough hair to fill the thin spots. If there isn’t enough hair to hold a row, she’d point you towards a topper or wig instead. And, in her words, “Extensions done well should never hurt.” Pain, burning, redness or bumps mean call your stylist straight away.

Her full post is here: Losing Hair on a GLP-1? What I’d Want You to Know Before You Book Extensions. My interview asking whether hair extensions are bad for thinning hair is a good one to read next if you want more from her.

Covering it while it grows back: toppers and wigs

This is the bit I know best. When I first started wearing wigs, I’d leave the house with this paranoid feeling that everyone could tell and it might fly off at any second. The longer I wore one, the more normal it felt, and now it’s just part of my day.

With a shed, a topper is usually the first thing to look at. It clips into your own hair and covers the top and your parting, which is where shedding tends to show most. Uniwigs is a good place to start if you want lots to compare, and my Uniwigs code NEVEEN gets you 15% off. My best hair toppers UK post goes through eight of the toppers I’ve worn, from a 5.5×5.5 base up to 9×9. And if you can’t decide between a topper and a wig, my hair topper vs wig post should help you pick.

Shop Uniwigs hair toppers here15% off at Uniwigs with code NEVEEN

If your hair’s coming out a lot, keep the topper light and move the clips around now and then so they’re not pulling on the same spot every day (I go into this more in do hair toppers damage your hair). It’s the same less-is-more idea Kenzie has with extensions.

What I’d use while the shed settles

I’ve split the stuff you can buy into two groups, because what’s worth trying depends on where you are with it.

The Ordinary Multi-Peptide Serum for Hair Density

Buy The Ordinary Multi-Peptide Serum here60ml at LOOKFANTASTIC

More places to buy▾Tap to see where to buy

UK

• Boots
• Escentual
• Cloud 10 Beauty15% discount code built into this link

UK & US

• Amazon

US only

• Sephora
• Ulta

This is the one I keep buying. It’s a light, water-based scalp serum from The Ordinary, alcohol-free and silicone-free, and the brand says it helps hair look thicker and fuller at the root. Most of the work comes from peptides and plant extracts. Redensyl mixes larch and green tea extracts with glycine and zinc, and Procapil pairs a peptide with olive leaf and grapefruit extracts, which The Ordinary says helps boost scalp energy. Capixyl is another peptide, with red clover. Baicapil comes from Chinese skullcap with soy and wheat germ, and there’s caffeine in there too.

You massage a few drops into a clean, dry scalp once a day (bedtime is easiest) and leave it in. The Ordinary says to patch test first, and not to use it at the same time as their direct acids or vitamin C. Don’t expect a serum to stop a shed. It’s a nice thing to do for your scalp while your hair settles. It gets a mention in my hair fall serums post too.

Free Soul Hair, Skin and Nails Gummies

Buy the Free Soul gummies here25% off, added automatically through my link

If you’re eating a lot less than you used to, a supplement can help fill some gaps. Get your bloods checked first though, because if you’re low on iron a gummy won’t fix that. If yours has biotin in it, tell your doctor before any blood test, because the FDA has warned that biotin can throw off some lab results. I compared the Free Soul ones in my hair, skin and nails vitamins post. Shop through the button above and you get 25% off, added automatically at checkout.

Mounjaro hair loss not growing back? What to try after six months

If you’re still shedding heavily after six months, or the shed has shown up thinning that was there before, it isn’t a wait-it-out shed any more. That’s when I’d go back to my GP and start looking at actual hair loss treatment.

Hair + Me

Start Hair + Me hereFirst month £4.99 with code NEVEENWOOD

I’m a Hair + Me ambassador and I’m on it myself right now, so you know where I stand. It’s an online hair loss service. You fill in a consultation online, and once it’s been reviewed they send you a treatment plan. If you’re on Mounjaro, put that in the consultation so they can factor it in. My Hair + Me review has my full update, and my Hair and Me discount code page has the code details.

Minoxidil (Regaine for Women)

Buy Regaine for Women hereOnce a Day foam at LOOKFANTASTIC

More places to buy▾Tap to see where to buy

UK

• Click Pharmacy
• Amazon UK

US only

• Amazon US

Click Pharmacy sells the 2% solution, used twice a day. In the US it’s sold as Women’s Rogaine 5% foam.

Minoxidil is the main over-the-counter hair loss treatment for women in the UK. Click Pharmacy sells Regaine for Women (2% minoxidil, used twice a day), and LOOKFANTASTIC has the Once a Day foam. But the NHS lists minoxidil as a treatment for pattern hair loss, not for a temporary shed, and a shed from weight loss usually sorts itself out on its own. So minoxidil makes most sense if your shed has shown up thinning underneath, or it hasn’t settled after six months and your GP agrees. It can make you shed more in the first month. You need to give it about four months before you’ll see anything, and it’s not for pregnancy or breastfeeding. Talk to a doctor first if you have heart or blood pressure problems. And if you have a cat, please read my post about minoxidil and pets first.

FAQs

Does Mounjaro hair loss grow back?

In most cases, yes. The shed linked to fast weight loss is usually temporary and the hair tends to regrow once your weight settles. If it doesn’t, or it’s left you with thinning you didn’t have before, see your GP.

How long does Mounjaro hair loss last?

It usually starts two to four months after the weight starts coming off and settles within about six months. The American Academy of Dermatology says hair usually gets back to its normal fullness within six to nine months.

Does Wegovy cause hair loss too?

It can. In the Wegovy trials about 3% of people reported hair loss, compared with about 1% on placebo.

Should I stop Mounjaro if my hair is falling out?

Not without talking to your GP or prescriber first. Tell them about the hair loss and ask about blood tests for things like iron, vitamin D and thyroid.

Can I wear a topper or extensions while I’m shedding?

Usually, as long as you keep it light. A topper can cover the top while it grows back. With extensions, a good stylist will check how much hair you have left and may suggest waiting or using less hair.

Are tape in extensions OK if I’m losing hair on Mounjaro?

Kenzie Moon from Wefts + Waves wouldn’t recommend them on shedding hair. Tape-ins go in with an adhesive, and getting that out can cause even more shedding if it isn’t done carefully.

Where to buy

I’m not a doctor, so please treat this as a starting point for a chat with your GP, not medical advice. I’m a paid Hair + Me ambassador, and the links in this post are affiliate links, so I earn commission if you buy through them or use my codes.

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