Important information about weight loss injections
There is increasing evidence that the weight loss injections Semaglutide (OZEMMPIC) and Tirzepatide (MOUNJARO) may affect the absorption of oral hormonal medication used in contraception or HRT. This is because they delay the stomach emptying and hence the absorption of the medication potentially reducing its effect.
Contraception:
If you are taking the oral combined contraceptive pill or the progesterone only pill should contact their prescriber to discuss the potential effect. Those taking Tirzepatide should consider switching to a non oral method and should contact the GP or sexual health clinic (01904 721111) to discuss other contraceptive choices. Alternatively, women should add a barrier method, for four weeks after initiation and for four weeks after each dose increase to prevent unwanted pregnancy.
HRT:
Women taking oral oestrogen should contact their prescriber to switch to an alternative type such as gel or patch. Women taking oral progesterone will need to contact their prescriber to discuss an alternative form of the medication or possibly change the dose. This is because you may not be getting an adequate dose to protect the womb lining. This applies to both Tirzepatide and Semaglutide.
Dr Patel June 2025
Ref: Primary Care Women’s Health Society – April 2025