In case you missed the latest chapter in the story of weight-loss medications going mainstream, these days, everyone’s talking about #OzempicBabies.
Over the past year-plus, people using prescription weight-loss medications—not just Ozempic but other popular injectable GLP-1 agonists—have taken to social media to share stories of unexpectedly becoming pregnant, often following years of infertility struggles, or even while taking birth control pills. As more stories went viral, the media went so far as to declare an Ozempic Baby Boom. While the idea that the popularity of weight-loss drugs is leading to a major increase in fertility has yet to be confirmed by data, it turns out that there are a few critical things any woman of childbearing age should know when taking GLP-1 meds—and the word hasn’t necessarily gotten out about all of them.
Example: The U.K. equivalent of the FDA recently put out an alert letting women know that some popular weight-loss medications may cause oral contraceptives to fail, while also posing potential risks to unborn babies. The former isn’t actually breaking news; the fact that certain weight-loss drugs may prevent oral contraceptives from working properly is spelled out right on the packaging insert. Yet with many people buying off-brand, compounded weight loss drugs, often without adequate oversight by a medical provider, many women remain unaware of this risk.
That lower price tag comes with some big risks.
The details to know: The weight-loss treatment tirzepatide (including the brand-name drugs Zepbound and Mounjaro) can interfere with the absorption of oral birth control, in part because it makes the stomach empty much more slowly. This has been shown to reduce the concentration of contraceptives in the bloodstream by up to 20 percent. Therefore, both the drug manufacturers and doctors advise that anyone using oral contraceptives should add condoms as a backup method for at least four weeks after starting tirzepatide injections, or after any dose increase (the risk decreases outside that one-month window). Another option is to switch to a non-oral birth control method, like an IUD, implant, or ring, all of which are unaffected by tirzepatide.
As for other popular GLP-1s like semaglutide (including brand name medications Ozempic and Wegovy) and liraglutide (Saxenda), they affect gastric enzymes slightly differently than tirzepatide does. Based on clinical studies to date, there is no evidence that semaglutides compromise the effectiveness of oral contraceptives, and some health organizations like Planned Parenthood maintain that they’re safe to use with the pill. However, doctors report seeing real-world cases of breakthrough bleeding and unintended pregnancy associated with all GLP-1 weight-loss injections, and prefer that women play it safe and use backup condoms or non-oral contraceptives.
“I guide patients who are committed to staying on oral contraceptives while using these medications to treat the first month like they’re not protected at all,” says New York-based endocrinologist and obesity medicine specialist Dr. Rekha Kumar, MD, head of medical affairs for the telehealth weight care provider Found. “What's particularly concerning is that emergency contraception could also be compromised if you're on weight-loss medication. This means the safety net many women rely on may not work when they need it most.”
It’s also important to know that vomiting and diarrhea are potential side effects for all GLP-1 drugs, and this can compromise the effectiveness of oral birth control. If you vomit within three hours of taking your birth-control pill, or experience diarrhea for more than 24 hours, experts recommend using condoms as backup and consulting with your doctor on how to proceed going forward.
Then there’s one more factor to weigh in when you’re a woman of childbearing age on weight-loss medication: People who are obese and lose a significant amount of weight frequently begin to experience more regular periods, more balanced hormones, and improved ovulation, especially if they have polycystic ovary syndrome (PCOS). These changes have the potential to lead to surprise pregnancies. “Many women who are overweight or obese have tried unsuccessfully to get pregnant in the past, but once they start to lose weight, they find themselves pregnant,” says Dr. Jennifer Brown, MD, a board-certified obesity medicine doctor at MyObesityTeam.
In some cases, there’s also a delay in women taking GLP-1s medications, figuring out that they’re pregnant—when you’re used to irregular periods, it can be harder to notice missing one. That’s concerning because the risks that weight-loss medications pose to pregnant women and their babies are still unknown. Some animal studies have linked them to increased risk of miscarriage and birth defects (though population-based studies have not confirmed this), and like many drugs, they have not been clinically tested in pregnant women.
“Most of these drugs should not be taken during pregnancy due to potential risks,” advises Dr. Christine Ren-Fielding, Professor of Surgery at NYU School of Medicine, Director of the NYU Langone Weight Management Program and Chief of the Division of Bariatric Surgery. “For this reason, if you are on a weight-loss medication, you should also be on a reliable form of birth control. If you are planning to become pregnant, you must stop taking these medications beforehand.”
As a general rule, women should discontinue weight-loss medications at least two months prior to a planned pregnancy, unless advised otherwise by a doctor (in some cases, the benefits of using one of these medications during pregnancy—such as to treat diabetes—may outweigh the potential risks).
To better understand the risks weight-loss medications pose during pregnancy, manufacturers of GLP-1 drugs have created registries for collecting data from people who get pregnant while using them. For the time being, anyone using weight-loss medication who wants to get pregnant should work with an obesity specialist in addition to an ob-gyn before, during, and after pregnancy to ensure that their pursuit of a healthy weight doesn’t interfere with their chances of having a healthy pregnancy.
Brands like Kourtney Kardashian’s Lemme are claiming to provide the same benefits as GLP-1 medications like Ozempic, Wegovy, and Mounjaro. But the truth is, these supplements have little to nothing in common with the drugs.
