A recent warning from the United Kingdom’s drug regulator has reignited concerns over whether widely used medications for weight loss and diabetes may interfere with the effectiveness of hormonal birth control.
On June 5, the Medicines and Healthcare products Regulatory Agency (MHRA) issued an alert regarding reports of pregnancies among users of drugs such as Ozempic, Wegovy, and Mounjaro—sometimes informally called “skinny jabs.”
“Women taking popular medicines for weight loss and diabetes… are being reminded to use effective contraception while taking these medicines,” the agency stated.
Ozempic and Wegovy contain semaglutide, while Mounjaro contains tirzepatide. These medications belong to a class known as GLP-1 receptor agonists, which work by mimicking gut hormones to increase insulin secretion, slow digestion, and suppress appetite.
Because these drugs delay the absorption of food, they may also affect how oral contraceptives are absorbed, according to Dr. Togas Tulandi, chief of obstetrics and gynecology at the McGill University Health Centre. He emphasized that non-oral contraceptive methods—such as intrauterine devices (IUDs) or implants—remain unaffected and are still reliable.
The MHRA also recommends that individuals using birth control pills consider a barrier method, like condoms, for added protection. Additionally, these medications should be avoided during pregnancy, while attempting to conceive, or while breastfeeding, due to limited safety data.
“Anyone who becomes pregnant while taking these drugs should consult a healthcare provider and discontinue use immediately,” the MHRA advised.
While this marks the first official advisory of its kind in the U.K., the topic has already been a point of discussion within online forums and among healthcare professionals.
