Jump to: Safety considerations | What is HRT? | What is Mounjaro? | Can you take them together? | Potential benefits | Common questions | Take home message
You can take Mounjaro while you’re on HRT as the combination is generally considered safe. Additionally, research suggests that combining GLP-1 medications with HRT leads to more weight loss than GLP-1 medications without HRT.
Research from the journal Menopause shows women using GLP-1 medications alongside HRT lost 16% of their body weight after 12 months, compared to 12% in those not on HRT.
However, Mounjaro may reduce the effectiveness of oral HRT medication due to how it influences the function of the gut.
Research shows Mounjaro can reduce absorption of oral contraceptives, prompting medical experts to express concerns about similar effects on oral HRT medications.
Some GP practices have been writing to patients about potential interactions between these medications, though the effect depends on which type of HRT you’re using.
Keep reading for a more detailed analysis of Mounjaro, HRT, and which type of HRT medication may be effected by Mounjaro.
Safety considerations
Whether there’s an interaction between Mounjaro and your HRT medication depends on which type of HRT you’re using.
Oral HRT tablets (potentially affected):
Your GP may have written about potential interactions because Mounjaro can reduce absorption of oral hormone tablets.
While no studies have specifically tested oral HRT medications, research shows Mounjaro reduces oral contraceptive absorption.
The British Menopause Society is applying this caution to oral progesterone and oestrogen tablets used in HRT.
HRT patches and gels (not affected):
These go straight through your skin, so Mounjaro can’t interfere with how they’re absorbed. If you’re using Estrogel, Sandrena gel, or any HRT patches, there’s no evidence or suggestion that Mounjaro would reduce their effectiveness.
The Mirena coil (not affected):
The Mirena coil releases hormones directly into your uterus, so Mounjaro doesn’t affect it.
What this means:
If you’re taking oral HRT tablets, your doctor might suggest temporarily adjusting your dose or switching to patches during your first month on Mounjaro. This isn’t because the combination is dangerous; it’s ensuring your HRT remains effective.
Most UK women use combination HRT tablets like Kliovance or Femoston. If you’re unsure which type you’re taking, check with your pharmacy.
What is HRT?
Hormone replacement therapy (HRT) involves taking oestrogen, with or without progesterone, to replace the hormones the body stops producing during menopause.
HRT can help alleviate many of the unpleasant symptoms of menopause, such as hot flashes, night sweats, mood changes, and vaginal dryness.
Some studies have also suggested HRT may have additional benefits, including potentially reducing the risk of heart disease and osteoporosis in some women.
HRT is typically prescribed as pills, skin patches, gels, or creams. The specific type and dose are tailored to each individual based on their symptoms and health history.
What is Mounjaro?
Mounjaro is a dual-action weight-loss injection. It supports weight loss by mimicking two hormones, GLP-1 and GIP, that communicate with the brain’s appetite control centre, the hypothalamus, to lower hunger and food-seeking behaviour.
By lowering hunger and our desire to eat, Mounjaro helps us eat fewer calories to achieve a calorie deficit.
A calorie deficit occurs when we consume fewer calories than our body needs to fuel its essential functions, such as digestion, blood flow, and brain function.
By creating a calorie deficit, our bodies will ‘burn’ the excess fat stored for energy, and we’ll lose weight.
Mounjaro also slows down the rate at which we digest food so that our stomach and gut send signals to the brain to signal the feeling of fullness.
So, Mounjaro supports weight loss by making us feel less hungry through two mechanisms:
- Communicating with the brain’s appetite control centre
- Slowing the rate that food is digested
Research shows that Mounjaro leads to an average weight loss of around 26% after one year.
Can you take them together?
It’s generally considered safe to take Mounjaro (tirzepatide) while also using HRT during menopause.
The two treatments work through different mechanisms and do not appear to interact in a way that would cause safety concerns, beyond the potential absorption issue with oral medications.
Research suggests the combination of GLP-1 medications like Mounjaro and HRT may be particularly beneficial for weight loss in menopausal women.
The hormonal changes that occur during menopause make weight loss extremely challenging for many women.
Factors like decreased metabolic rate, increased hunger, and changes in body fat distribution all contribute to this difficulty.
By taking Mounjaro alongside HRT, women may be able to better counteract some of these menopausal effects:
- Mounjaro’s appetite-lowering effect could help overcome increased hunger and food cravings
- The metabolic benefits of HRT may complement Mounjaro’s fat-burning effects
- HRT may help mitigate some of the negative impacts of oestrogen decline on body composition
The study published in Menopause found that combining a GLP-1 medication (similar to Mounjaro) and HRT led to an average weight loss of 16%, compared to 12% for those not using HRT.
However, more research is needed to understand this interaction fully, particularly with different types of HRT.
Potential benefits of combining Mounjaro and HRT
For women with both menopausal symptoms and weight concerns, the combination may offer several advantages.
Enhanced weight management:
The research suggests combining them may be more effective than either treatment alone, though results vary between individuals.
Symptom management:
Some women find their menopausal symptoms become more manageable as they lose weight, though this isn’t guaranteed for everyone.
Metabolic improvements:
Both medications can help with insulin resistance, which commonly develops during menopause.
However, it’s crucial to understand that:
- Individual responses vary considerably
- Weight loss isn’t guaranteed with any medication
- Both treatments require ongoing medical supervision
- The oral HRT interaction needs careful monitoring
Common questions about Mounjaro and HRT
My GP sent a warning letter about drug interactions; should I be concerned?
These letters are precautionary based on proven contraceptive interactions. Your doctor is being appropriately cautious. The key is distinguishing between oral and non-oral HRT types.
Do I need to stop my HRT to start Mounjaro?
No. If you’re using patches, gels, or have a Mirena coil, continue as normal. For oral tablets, your doctor may need to review your treatment.
How do I know if my oral HRT is still working effectively?
Watch for return of menopausal symptoms like hot flushes or mood changes. Contact your prescriber if symptoms return after starting Mounjaro.
Can I switch from tablets to patches?
Yes, this may be a practical solution. Your doctor can help you transition between different HRT types.
What about the Mirena coil for HRT?
The Mirena isn’t affected by Mounjaro as it releases hormones directly into your uterus.
Take home message
While the relationship between Mounjaro and HRT appears manageable, important safety considerations apply depending on your HRT type.
If you’re using HRT patches, gels, or the Mirena coil, there’s no evidence of a direct interaction between Mounjaro and these medications.
If you’re taking oral HRT tablets, discuss with your prescriber whether dose adjustments or switching to non-oral alternatives might be appropriate.
The combination may offer enhanced weight loss benefits for some menopausal women, though individual results vary. Success depends on working closely with your healthcare team to monitor both your HRT effectiveness and your response to Mounjaro.
Most importantly, any medication decisions should be made in consultation with healthcare professionals who understand your individual medical history and circumstances.
Second Nature's Mounjaro programme
Second Nature provides Mounjaro as part of our Mounjaro weight-loss programme
Why choose Second Nature over other medication providers, assuming you’re eligible?
Because peace of mind matters.
We’ve had the privilege of working with the NHS for over eight years, helping people across the UK take meaningful steps toward a healthier, happier life.
Our programmes are designed to meet people where they are, whether that means support with weight loss through compassionate one-to-one health coaching, or access to the latest weight-loss medications (like Mounjaro) delivered alongside expert care from a multidisciplinary team of doctors, psychologists, dietitians, and personal trainers.
At the heart of everything we do is a simple belief: real, lasting change comes from building better habits, not relying on quick fixes. We’re here to support that change every step of the way.
With over a decade of experience, thousands of lives changed, and a long-standing record of delivering programmes used by the NHS, we believe we're the UK’s most trusted weight-loss programme.
We hope to offer you something invaluable: peace of mind, and the support you need to take that first step.
