Mounjaro and HRT: Weight Loss Treatment During Perimenopause and Menopause

Taking HRT does not on its own rule out Mounjaro or another GLP-1 weight loss medicine, and you should not stop your HRT to start one. What matters is how your HRT is taken: these medicines can slow how quickly your stomach empties, which can change how tablets and capsules are absorbed, so the British Menopause Society's main concern is a progestogen taken by mouth. Patches, gels, sprays and the hormonal coil are not taken by mouth.

None of the four medicines' UK product information mentions HRT, and very little research has looked at the two together. The progestogen in combined HRT is the part that protects the lining of your womb. This guide explains why its form matters, which forms of HRT are not taken by mouth, what to ask your GP, and why contraception still matters in the perimenopause.

It covers Mounjaro (tirzepatide), Wegovy injections and Wegovy tablets (semaglutide), and Foundayo (orforglipron). For our other guides on periods, contraception and pregnancy, see women's health on weight-loss treatment.

Can you take Mounjaro and HRT together?

There is no listed interaction between them. The UK product information for Mounjaro, Wegovy, Wegovy tablets and Foundayo says nothing about HRT, and neither does the MHRA's public guidance on GLP-1 medicines. That is not the same as the question having been studied. The British Menopause Society (BMS) points out that nothing has been measured yet: not the effect on a progestogen taken by mouth, not whether its dose needs to change, and not the effect on bleeding or on the womb lining.

So the advice that exists is cautious and rests on expert opinion. The BMS tool for clinicians, published in April 2025, focuses on semaglutide and tirzepatide, and says its general principles apply to the wider group of these medicines. Foundayo was licensed in the UK after it was written. It belongs to the same group, and its product information says it slows stomach emptying too.

Why does it matter how your HRT is taken?

If you still have your womb, HRT usually has two parts. Oestrogen eases menopause symptoms, and a progestogen protects the lining of the womb: the NHS explains that taking both helps protect against the risk of womb cancer. If you have had a hysterectomy, you usually take oestrogen on its own.

GLP-1 medicines can slow how quickly your stomach empties, and that can change how medicines taken by mouth are absorbed. The clearest example is the contraceptive pill. In a study, a single 5mg dose of Mounjaro lowered the peak levels of a combined pill's hormones by more than half, which is why Mounjaro comes with extra contraception advice. Our guide to contraception and pregnancy on GLP-1 treatment covers that in detail.

Nobody has measured the same thing for HRT. The BMS's concern is that a progestogen taken by mouth might be absorbed less well, which in theory could leave the womb lining less well protected. That is why it suggests clinicians consider a form of progestogen that is not taken by mouth. It also suggests considering oestrogen through the skin for women who take oestrogen tablets. Oestrogen absorbed through the skin does not depend on how quickly your stomach empties.

Which forms of HRT are taken by mouth?

HRT comes in several forms, the NHS says:

• Tablets, oestrogen-only or combined, taken by mouth. A separate progestogen can also be a tablet or capsule.
• Skin patches, oestrogen-only or combined, changed every few days.
• Oestrogen gel or spray, used on the skin once a day, with a progestogen as well if you still have your womb.
• The hormonal coil (IUS), placed in the womb, where it releases a progestogen. It also works as contraception.
• Vaginal oestrogen, a cream, gel, pessary, vaginal tablet or ring used inside the vagina.

Patches, gels, sprays, the hormonal coil and vaginal oestrogen are not taken by mouth. The BMS tool does not suggest changing a combined patch or a hormonal coil because of a weight loss medicine. The part to look at is any HRT you swallow, and the progestogen most of all.

Can you take Wegovy, Wegovy tablets or Foundayo with HRT?

The same applies to each of them: none of their UK product information mentions HRT, and the difference is how each one is taken and what it means for a contraceptive pill.

What should you do if you take HRT?

• Keep taking your HRT as prescribed. Do not stop it, or change how you take it, without speaking to your GP or menopause clinic.
• Tell us in the consultation. It asks you to list every medicine you take. Include your HRT and how you take it (tablet, capsule, patch, gel, spray, coil or vaginal), any contraception, and any herbal remedy.
• Tell your GP you are starting a weight loss medicine, especially if they prescribe your HRT.
• If your progestogen is a tablet or capsule, ask your GP whether another form would suit you while you are on treatment, for example a combined patch or a hormonal coil, as your GP decides.
• If your oestrogen is a tablet, mention that too. Patches, gels and sprays are not taken by mouth.
• On Wegovy tablets, take any HRT tablet or capsule at least 30 minutes after your Wegovy tablet, as with any other medicine by mouth. Our guide on how to take the Wegovy pill explains the 30 minute rule.
• On Foundayo, tell us about any herbal remedy. The Foundayo product information says St John's wort may make Foundayo less effective and should be avoided with it, and the NHS warns that some herbal remedies sold for menopause symptoms can cause serious side effects with other medicines.

What if you have bleeding on HRT?

Irregular bleeding or spotting is common in the first months of HRT and usually settles within 6 months, the NHS says. On sequential combined HRT, a bleed at the end of each course of progestogen is expected. Speak to your GP if:

• you still have irregular bleeding more than 6 months after starting HRT
• your bleeding becomes heavier
• you have any bleeding after 12 months or more without a period, even once or only spotting

None of the four weight loss medicines lists bleeding or a change in periods as a side effect in its UK product information, so do not put new bleeding down to your weight loss medicine. Tell your GP you take it as well as your HRT: the BMS advises that unexpected bleeding in women taking both is assessed in line with national guidance. For periods before the menopause, see our guide to Mounjaro and periods.

Do you still need contraception in the perimenopause?

Yes, until a doctor or nurse tells you that you no longer need it. HRT is not a contraceptive, and the NHS says it is possible to get pregnant during the perimenopause. It advises contraception for 2 years after your final period if you are 40 to 49, and for 1 year if you are 50 or over, and says contraception is no longer needed after 55. HRT and hormonal contraception can both change your bleeding, so you may not know when your final period was: ask your GP when you can stop.

This matters on weight loss treatment for two reasons. These medicines must not be used in pregnancy. And if you use a contraceptive pill, Mounjaro and Foundayo can make it less reliable for a while. The NHS says you cannot take the combined pill at the same time as HRT, but a GP may suggest staying on the combined pill until 50 instead, and the progestogen-only pill can usually be taken alongside HRT. Both are pills taken by mouth, so the same advice applies to either. For Mounjaro, the counselling we give is:

Contraception (Mounjaro only): tirzepatide can reduce absorption of the contraceptive pill. Use a non-oral method or add condoms for 4 weeks after starting and for 4 weeks after each dose increase. Wegovy needs no extra precautions unless severe vomiting or diarrhoea occurs, then follow missed-pill guidance.

For Foundayo, the counselling we give is:

If you use the oral contraceptive pill, use a non-oral method or add a barrier method such as condoms for 30 days after starting treatment and for 30 days after each dose increase.

On Wegovy tablets, take your pill at least 30 minutes after the Wegovy tablet. A coil does not rely on your stomach, so these medicines do not affect it in the same way, and the NHS notes that the hormonal coil used in HRT also works as contraception.

Is it the menopause, your HRT or your weight loss medicine?

Some symptoms overlap, which can make it hard to tell what is causing what. Tiredness is listed as a side effect of all four medicines, and the NHS lists it among the side effects of progestogen. Feeling sick and diarrhoea are common with these medicines, especially while the dose goes up, and the NHS lists both as possible side effects of HRT. Hair thinning appears in all three lists: menopause, HRT and the weight loss medicines. Our guide to Mounjaro side effects lists how often each one happened in the trials.

Poor sleep, low mood, anxiety and brain fog are common in the perimenopause and menopause, the NHS says. They are not listed as side effects of these four medicines in their UK product information. Whatever you think the cause is, tell us how you are feeling, and see your GP if poor sleep or low mood is affecting your daily life. Our guides on whether Mounjaro makes you tired and whether Mounjaro causes hair loss go into more detail, and our guide on whether Mounjaro can cause depression covers mood.

Can you take weight loss medication during the menopause?

Yes, on the same terms as anyone else: the menopause does not change whether you can have treatment. Eligibility is the same for everyone, at any stage of life: you need to be 18 to 85, with a BMI of 30 or more, or a BMI of 27 to 29.9 with a weight-related condition such as high blood pressure, raised cholesterol, obstructive sleep apnoea, heart disease, prediabetes or type 2 diabetes. Menopause on its own is not one of those conditions, and taking HRT does not, by itself, rule you out.

The NHS says weight gain is common during the perimenopause and menopause, often around the stomach, and that there is little evidence most types of HRT cause it. These medicines are licensed for weight management, alongside a reduced-calorie diet and more physical activity. They are not a treatment for menopause symptoms, and they do not replace HRT.

What other weight loss options are there in the menopause?

A GLP-1 medicine is not the only route. Orlistat, which we also supply, is a different kind of medicine: it works in the gut by reducing how much fat from food is absorbed. If you take a contraceptive pill, its product information recommends an extra method if you have severe diarrhoea. Your GP can also tell you about NHS weight management services, some of which you can refer yourself to, and may offer the NHS digital weight management programme if your weight affects a condition such as high blood pressure or type 2 diabetes. For menopause symptoms themselves, your GP or a menopause clinic is the place to start.

How we check this before you start

Our consultation asks you to list every medicine you take, prescribed or bought, and whether you take the contraceptive pill. A GPhC-registered pharmacist then reviews every consultation, and may contact you about your HRT or contraception before anything is supplied.

If you would like to see whether treatment is right for you, the consultation is free and takes a few minutes: check if you are eligible. To compare the medicines first, see our weight loss treatments.