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: Patient-information-GLP-1-agonists-andcontraception.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.
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 or increasing
the dose of your weight loss medication.
Using progesterone vaginally:
- This is not licensed but is commonly used. You can continue this if already
prescribed.
Need help
Please contact us via deddingtonhealthcentre.co.uk/services/managing-your-healthonline/ to discuss your HRT or contraception options while using weight loss
medication.