The Medicines and Healthcare products Regulatory Agency (MHRA) in the UK warned on Thursday that women using injections for weight loss should use effective contraceptives if they do not want to get pregnant, as reported by Efe. It also warned pregnant women using these drugs that the effect on the fetus is unknown.
The warning comes after the British agency recorded over 40 pregnancies among women receiving the new family of injectable drugs for diabetes and obesity (Ozempic, Wegovy, Mounjaro...).
By "effective contraceptives," the MHRA refers to oral contraceptives (the pill) and non-oral methods (contraceptive implant, IUD, or condoms). However, it warns that Mounjaro could reduce the effectiveness of oral contraceptives in overweight women, so it recommends that Mounjaro patients also use non-oral contraceptive methods such as condoms, especially during the first four weeks of treatment and with each dose increase. The agency recorded 26 pregnancies among women treated with this medication.
It also reports eight pregnancies in women treated with Wegovy and Ozempic and nine among Saxenda patients.
Although it is still unclear why these drugs may affect the effectiveness of the pill, according to the BBC, it could be due to some of their common side effects (vomiting, diarrhea...) and the fact that they slow down gastric emptying. Additionally, weight loss in obese or overweight women could also increase their fertility and facilitate pregnancy.
On the other hand, the British agency recommends that women wait two months before trying to get pregnant once they have stopped weight loss treatment and continue using contraceptive methods for two months in the case of Wegovy and Ozempic, and one month for Mounjaro.
The MHRA stated that these medications should not be taken during pregnancy, while trying to conceive, or during breastfeeding, and women who become pregnant should stop injections.
"This is because there is not enough safety data to determine if taking the medication could harm the baby," stated the MHRA, adding that effective contraceptive methods include the oral pill, contraceptive implants, IUDs, and condoms.
MHRA's Safety Director, Alison Cave, reminded that "weight loss injections are authorized medications to treat specific medical conditions and should not be used for aesthetic or cosmetic purposes. They are not a quick solution for weight loss, and their safety has not been evaluated when used in this manner."