Mounjaro and HRT: What you need to know

It is not uncommon to notice weight gain when you are going through the menopause. Menopause can cause your body to store more fat around the stomach area, often because of declining oestrogen levels. Lower oestrogen levels can lead to a slower metabolism, insulin resistance, and increased appetite, causing weight gain.

Hormone replacement therapy (HRT) is used to manage the symptoms of menopause, but also supports weight management by improving symptoms that promote weight gain like poor sleep, low energy, and a slower metabolism.

Mounjaro is a once‑weekly injection used to treat type 2 diabetes and obesity in adults. It works by activating two hormone pathways (GLP‑1 and GIP) which help the body regulate blood sugar, increase insulin release when needed, slow digestion, and reduce appetite. These effects work together to lower blood glucose and support weight loss when used alongside healthy dietary and lifestyle changes.

Why is weight loss harder during menopause?

Some changes in the body during menopause make it easier to gain weight, and even harder to lose it. For example, loss of muscle mass, insulin resistance, and change in appetite hormones causing more hunger can all increase weight gain and make it harder to lose weight.

Can taking Mounjaro and HRT improve weight loss results?

Yes, using HRT and Mounjaro can help improve weight loss efforts, when used as prescribed by your healthcare provider.

HRT does not directly cause weight loss but can improve other menopause symptoms like poor sleep, tiredness, insulin resistance, mood changes, and appetite control, which can indirectly help your weight loss efforts.

Mounjaro directly helps with weight loss by reducing appetite and slowing stomach emptying, making you feel fuller for longer and helping you eat less over time.

Together, HRT and Mounjaro can improve weight loss outcomes, but you will need to be carefully monitored by your healthcare provider to also make sure your HRT is still working well for you.

You should speak to your doctor about HRT and Mounjaro if you:

• are thinking about starting both HRT and Mounjaro for the first time
• are already using HRT and want to start weight loss injections like Mounjaro for the first time
• have already been using Mounjaro but want to start HRT for menopause symptoms

Your doctor should help you understand what to expect when you start HRT and Mounjaro, including the best way to take them, when to expect results and some common side effects you may experience.

Your doctor should also discuss how taking both HRT and Mounjaro can help you balance your overall health and weight‑loss goals, while keeping your menopause symptoms under control.

What should I do if I’m taking HRT but want to start using Mounjaro?

You should first speak with your doctor if you want to start taking Mounjaro for weight loss and you are already using HRT to manage menopause symptoms. They will need to review your medical history and other medications you are taking to make sure it is safe for you to use both HRT and Mounjaro.

Your doctor will discuss the best forms of HRT to use when starting Mounjaro for weight loss, to make sure your HRT also continues to work effectively for you.

Can you take Mounjaro and HRT together?

Yes, it’s possible for some people to take them together but you will need to speak with your doctor to check that it is safe for you to do so. They will discuss the risks and benefits, any possible interactions, and some common side effects you may experience. They will also advise on the best type of HRT to use when also taking Mounjaro to make sure it is safe and continues to work effectively for you.

Yes, but not all types of HRT. Mounjaro causes delayed stomach emptying, which can reduce absorption of oral HRT progesterone. This may mean the womb lining isn’t fully protected, and can lead to side effects like unexpected vaginal bleeding.

Mounjaro does not affect the transdermal HRT (patches, gels, sprays) and Mirena coil because they bypass the digestive system.

Mounjaro and oral HRT

It is possible to use both oral HRT and Mounjaro, but the oral HRT may not work as effectively as before. This is because Mounjaro slows stomach emptying, so oral medications spend more time in the stomach. This can lead to:

• lower hormone absorption, especially oral HRT progesterone
• reduced menopause symptom control, such as return of hot flushes, fatigue, or poor sleep
• insufficient endometrial protection (womb lining), which can lead to unexpected vaginal bleeding

If you are already taking oral HRT and want to start Mounjaro, you need to speak to a doctor about a review of your HRT. Some options to discuss as advised by the British Menopause Society include:

• switching to non-oral HRT forms like HRT patches, sprays, gels, the Mirena coil, or other vaginal HRT forms
• continuing with oral HRT but increasing the dose for the first 4 weeks when you start Mounjaro, and keeping an increased dose for the first 4 weeks every time you increase your Mounjaro dose

The goal here is to make sure both Mounjaro and HRT treatments are working well for you, to meet your weight loss goals, offer menopause symptom relief and long-term protection of your womb lining.

Mounjaro and HRT patches or gel

Using Mounjaro together with transdermal HRT (patches or gel) is generally the safest and most reliable combination because these forms of HRT are not absorbed through the digestive system. They work together well to maintain both your weight loss goals and effective menopause symptom control.

As transdermal HRT is absorbed through the skin, using it with Mounjaro which causes delayed stomach emptying means your transdermal HRT will still work well as it is not absorbed through the stomach.

If your HRT is a combination of transdermal (patches or gel) and another form of progesterone (for womb lining protection), the most reliable progesterone option to use with Mounjaro is a non oral form like Mirena coil. The Mirena coil’s progesterone bypasses the digestive system, so it is not affected by delayed stomach emptying caused by using Mounjaro.

Can I take Mounjaro if I'm already on HRT?

Yes, you can take Mounjaro if you’re already on HRT, but the combination works best when your HRT are non‑oral forms like patches, sprays, gel, the Mirena coil, or other vaginal HRT forms. Speak to your doctor to discuss your options if you are currently using oral HRT and want to start Mounjaro.

Which type of HRT is safest to use with Mounjaro?

The safest forms of HRT to use with Mounjaro are the HRT gels, patches, sprays, the Mirena coil, and other vaginal HRT preparations. These HRT forms are safer because they are not absorbed through the stomach, where Mounjaro can cause a delay in movement and absorption of food and medication.

Do I need to switch from oral HRT tablets to patches if I start Mounjaro?

It is recommended. The British Menopause Society advises a switch from oral HRT to non oral forms like patches or gels, when starting weight loss injections like Mounjaro. These forms of HRT are not absorbed through the digestive system where Mounjaro acts on, and your menopause symptoms can remain well controlled.

Can Mounjaro affect the Mirena coil?

No, there is currently no evidence of interaction between Mounjaro and the Mirena coil. The Mirena coil delivers progesterone locally inside the uterus (womb), so its effectiveness does not depend on digestion or absorption through the stomach, where Mounjaro acts on to slow stomach emptying, making you feel full for longer.

Does Mounjaro interact with oral progesterone like Utrogestan?

Yes, Mounjaro can interact with oral progesterone tablets like Utrogestan. Although the interaction isn’t dangerous, it can reduce how well oral progesterone is absorbed, because Mounjaro slows stomach emptying. This interaction can lead to unexpected vaginal bleeding, because your womb lining is not well protected as your body is not getting the right amount of oral progesterone.