‘Ozempic babies’ and birth control: U.K. warning raises concerns over weight-loss drugs

A recent warning from the United Kingdom’s drug regulator has renewed questions about whether popular weight-loss and diabetes medications could reduce the effectiveness of hormonal birth control.

The U.K.’s Medicines and Healthcare products Regulatory Agency (MHRA) issued an alert on June 5 about pregnancies among users of medications such as Ozempic, Wegovy and Mounjaro, sometimes referred to as “skinny jabs.”

“Women taking popular medicines for weight loss and diabetes… are being reminded to use effective contraception while taking these medicines,” the guidance said.

Ozempic and Wegovy, which both contain semaglutide, and Mounjaro, which contains tirzepatide, are part of a class of medications known as GLP-1 receptor agonists. These drugs mimic gut hormones to increase insulin production, slow digestion and suppress appetite.

“These medications delay the absorption of food, so they may also delay or reduce the absorption of the birth control pill,” Dr. Togas Tulandi, chief of obstetrics and gynecology at McGill University Health Centre said in a video interview with CTV News.ca.

Tulandi noted that non-oral methods, such as intrauterine devices (IUDs) or implants, are not affected by weight-loss drugs and remain effective.

The MHRA also advises people using the pill to use a barrier method, such as condoms-, reiterating that these medications should not be taken during pregnancy, while trying to conceive or while breastfeeding, due to limited safety data.

“Anyone who gets pregnant while using them should speak to their healthcare professional and stop the medicine as soon as possible,” the MHRA said.

Although this is the first formal warning of its kind in the U.K., the issue has been circulating in online communities and medical circles.

Some women shared surprise emergencies on platforms like TikTok and Reddit using the hashtag #OzempicBaby — with some saying it happened despite using the pill, and others linking increased fertility to weight loss or improved hormone regulation.

While widely promoted online for weight loss, not all GLP-1 drugs are approved for that use. In Canada, Ozempic and Mounjaro are approved for Type 2 diabetes in adults with obesity or related conditions, and Wegovy for weight management.

Health Canada told CTV News.ca in a statement that the U.K.’s alert is consistent with existing guidance in Canada.

“All Canadian product monographs for GLP-1 receptor agonists advise against using these drugs during pregnancy, and many include warnings about potential interactions with oral contraceptives,” it said.

Health Canada says it continues to monitor the safety of health products and will take action if new issues arise.

Novo Nordisk, the maker of Ozempic and Wegovy, says no clinically relevant interactions have been found between semaglutide and oral contraceptives containing ethinylestradiol and levonorgestrel. However, the company still recommends patients discontinue use if they become pregnant or plan to conceive.

“Patient safety is a top priority for Novo Nordisk, and we work closely with authorities and regulatory bodies worldwide to continuously monitor the safety and efficacy of our products,” company spokesperson Marie-Pier Burelle said in a statement to CTVNews.ca.

Tulandi advises people hoping to conceive to ideally focus on weight loss first, then stop the medication and try to become pregnant.

He also pointed to a lesser-known safety issue.

“If you’re taking this type of medication and you’re undergoing surgery, you should stop it at least two weeks before, because (while you take these medications) food absorption is delayed and when you undergo surgery, the food might still be in the stomach,” he said.

Failing to pause the medication could increase the risk of aspiration, where food enters the lungs. He said some patients have had surgeries cancelled as a result.