The UK's Medicines and Healthcare products Regulatory Agency (MHRA) has issued a warning to women using weight loss injections, including Ozempic, Wegovy, and Mounjaro, advising them to use effective contraception due to concerns about reduced effectiveness of the contraceptive pill and reports of pregnancies during treatment.

The MHRA advises that women taking GLP-1 medicines—such as Mounjaro, Ozempic, Wegovy, Saxenda, and Victoza—should use effective contraception while on these medications and for a certain period afterward before attempting to conceive. Specifically, the recommended waiting period is two months after discontinuation for Wegovy and Ozempic, and one month for Mounjaro.

This advisory comes after the MHRA received more than 40 pregnancy-related reports linked to these medications, raising concerns about their safety during pregnancy. Among these reports, 26 were associated with Mounjaro, raising particular concerns regarding the use of this drug in women of childbearing age.

Women have been sharing stories on social media about their so-called "Ozempic babies," including surprise pregnancies while on the pill. These accounts underscore the potential risk of unintended pregnancies and the importance of employing effective contraceptive methods during treatment with weight loss injections.

"Weight loss injections are authorized medicines to treat specific medical conditions and should not be used as aesthetic or cosmetic treatments. They are not a quick solution for weight loss, and their safety has not been evaluated when used in this way," stated Dr. Alison Cave, the Director of Safety at the MHRA, according to The Epoch Times.

The MHRA warns that weight-loss injections may reduce the effectiveness of contraceptive pills and hormone therapy, particularly in women who are overweight or obese. It is believed that the common gastrointestinal side effects of these medications, such as vomiting and diarrhea, may impair the absorption of oral contraceptives, thereby increasing the risk of unintended pregnancies.

As a result, the MHRA recommends that patients using weight-loss medications should use effective contraceptive methods during treatment, including contraceptive implants, intrauterine devices (IUDs), and condoms. Specifically, users of Mounjaro are advised to use condoms, especially during the first four weeks of treatment and after any dose increase, and to consider non-oral contraceptive methods.

The agency also advises that these drugs should not be taken during pregnancy, while trying to conceive, or during breastfeeding due to insufficient safety data regarding potential harm to the baby. Dr. Cave emphasized the importance of patient awareness, urging individuals to read the patient information leaflet or consult with a healthcare professional as part of the medication prescribing process.

Professor Sir Stephen O'Rahilly explained that the reduced effectiveness in contraception may be due to symptoms caused by weight loss injections. "The common side effects such as nausea and diarrhea can affect the absorption of the contraceptive pill," he said, emphasizing the need for additional contraceptive precautions.

GLP-1 receptor agonists, known as GLP-1 drugs, work by mimicking hormones that regulate appetite and help people feel fuller longer, contributing to their effectiveness for weight loss. They also slow the rate at which food is digested in the stomach, which may impact the absorption of oral medications, including contraceptives.

Some women have conceived just months after starting GLP-1 treatment. Therefore, women using weight-loss injections are advised to use effective contraception and wait up to two months after stopping the medication before attempting to become pregnant.

In addition to advising on contraception, the MHRA has issued an alert regarding the use of GLP-1 drugs for weight loss, raising concerns about their safety, particularly during pregnancy and breastfeeding. The agency states that there is insufficient safety data to determine whether GLP-1 class drugs could harm fetuses, and testing in animals has shown potential risks.

Experts have echoed the MHRA's concerns. Dr. Channa Jayasena noted, "Obesity reduces fertility in women. Therefore, women with obesity who are taking GLP-1 drugs are more likely to become pregnant than before losing weight." He also mentioned that while more research is needed, "women could accidentally get pregnant when taking GLP-1 drugs," and the guidance is sensible in pointing out this risk.

The MHRA encourages individuals who suspect they have experienced an adverse reaction to a GLP-1 medicine, or who suspect it is not a genuine product, to report it to the MHRA Yellow Card scheme. This system helps monitor the safety of medicines and take appropriate action when necessary.

Written with the help of a news-analysis system.