Patient information
If you are taking a privately prescribed weight loss injection (GLP-1 agonist) and are using contraception or HRT, it is essential that you are aware that these medications reduce the effectiveness of oral contraceptive pills and the oral progesterone element of HRT. This should have been discussed with you by the private provider and adjustments to contraception/ HRT made as necessary.
Contraception
More information regarding weight loss medications and contraception can be found here:
Faculty of sexual and reproductive healthcare
HRT – Hormone replacement therapy
The majority of women using HRT will be on combined HRT- containing both oestrogen and progesterone. Oral progesterone absorption may be affected by weight loss medications, meaning the lining of the womb may not be adequately protected.
Non-oral progesterone (patch or mirena coil) is preferred while using a GLP-1 agonist.
If oral progesterone is used, higher doses should be used for 4 weeks after starting medication AND 4 weeks after any dose increases.
Adjustments to HRT should have been discussed by weight loss medication providers.