Tirzepatide (Mounjaro™) was approved by the National Institute for Health and Care and Excellence (NICE) in the UK in December 2024: NICE (National Institute for Health and Care Excellence) guidance on Tirzepatide for managing overweight and obesity in adults.
We are anticipating guidance from NHS England which will help us implement our plans to prescribe this drug to people with the greatest clinical need in a safe and effective way, alongside a reduced-calorie diet, increased physical activity and psychological support.
Initially, Tirzepatide will be prescribed in Gloucestershire through a Specialist Weight Management Service. We are working with practices, pharmacies, Public Health, and the specialist service to ensure that those who are eligible for the drug are given the right care and support when they start the treatment to help them gain the greatest health benefits. This will include healthy lifestyle programmes to help people to lose weight through changes to their diet, nutrition, and physical activity.
We are advising the public that the medication is not currently available for weight loss via prescription from GP practices and that they should not contact practices to ask for it.
Important notice for patients using weight loss medications and taking the pill or HRT
Many patients are now using weight loss medications like Tirzepatide (Mounjaro) or Semaglutide (Ozempic, Wegovy, Rybelsus) — either for diabetes or privately for weight loss.
These medications work partly by slowing down how your stomach empties — which can affect how well other medicines (like the contraceptive pill or HRT tablets) are absorbed by your body.
If you take the contraceptive pill:
Tirzepatide (Mounjaro)
This medicine may reduce how well the pill works.
You should:
- Use a non-oral method (e.g. coil or implant) or
- Add a barrier method (like condoms) for 4 weeks after starting or increasing the dose.
- Use extra protection (like condoms) if you have vomiting or diarrhoea and follow the missed pill rules (see the patient information leaflet which comes with your pill) if you vomit within 3 hours of taking the pill or have diarrhoea for more than 24 hours.
Semaglutide (Ozempic, Wegovy, Rybelsus) and others
These do not appear to reduce the effectiveness of the pill. But side effects like vomiting or diarrhoea can still reduce how well the pill is absorbed. So, use extra protection (like condoms) if you have vomiting or diarrhoea and follow the missed pill rules (see the patient information leaflet which comes with your pill) if you vomit within 3 hours of taking the pill or have diarrhoea for more than 24 hours.
Please see further information here:
www.fsrh.org/Common/Uploaded%20files/documents/Patient-information-GLP-1-agonists-and-contraception.pdf
If you’re taking Hormone Replacement Therapy (HRT):
This applies if your HRT includes progesterone tablets like:
- Progesterone or Utrogestan
- Norethisterone
- Medroxyprogesterone acetate
There is some concern that weight loss medications – such as Tirzepatide (Mounjaro) and Semaglutide (Ozempic, Wegovy, Rybelsus) – may reduce how well these tablets are absorbed. This could lead to irregular bleeding and may affect the protection of your womb lining (potentially leading to an increased risk of endometrial cancer).
What are the options?
Please contact us to talk through the best choice for you.
Options include:
- Mirena coil (IUS): The ideal option in most cases. Works for 5 years as part of HRT and is also contraceptive. Please contact the practice if you would like to be added to our waiting list for a coil fit.
- Combined HRT patch: Contains both hormones (oestrogen + progestogen) and bypasses the stomach.
- Increase oral progesterone dose: Your GP may recommend a higher dose for 4 weeks after starting and after each dose increase of your weight loss medication.
- Using progesterone vaginally: This is not licensed but is commonly used. You can continue this if already prescribed.