It’s generally safe for most people to use Wegovy, a weekly injection for weight loss. Wegovy works by acting like GLP-1, a natural hormone that’s released when you eat, which makes you feel full.
But if you’re pregnant or breastfeeding, it’s not recommended that you take it. That’s because we don’t have enough scientific evidence to say for sure that it won’t harm your baby.
What about if you’re trying to get pregnant? Here, there’s specific advice you should follow. You also might be wondering whether Wegovy affects birth control. Read on—we’ve laid it all out for you below.
Wegovy and pregnancy
We don’t know a lot about Wegovy’s effects on pregnancy. That’s why the advice is to err on the side of caution and avoid Wegovy if you’re pregnant, because we can’t rule out that it might cause harm.
Besides, losing weight while pregnant isn’t recommended in any case. It can come with an increased chance of your baby being born smaller than expected.
But in terms of Wegovy, studies done in animals showed that there’s a higher chance of miscarriage and birth defects when using it. However, we don’t know whether these effects were due to Wegovy or the weight loss it caused.
There aren’t any studies about Wegovy and pregnancy in humans. This is important because animal studies don’t always indicate what will happen when a person takes a medication.
Though there is one report of someone getting pregnant while using Wegovy. Happily, aside from having low blood sugar after birth, the baby was healthy—and six months later they were developing normally. However, the person also experienced significant weight gain throughout the pregnancy after discontinuing the medication.
The fact remains that we don’t know enough to recommend the medicine for pregnant people. So, if you’re pregnant, you shouldn’t take Wegovy.
How about other weight loss injections, like Mounjaro? We’ve covered the advice here.
What happens if you get pregnant on Wegovy?
Contact your doctor right away and stop taking the medicine. Again, this is because we can’t guarantee that Wegovy is safe for your baby.
Can you take Wegovy while trying to get pregnant?
No, you shouldn’t do this. At risk of sounding like a broken record: we don’t know how Wegovy might affect your baby, so it’s safest to have none in your system while trying to get pregnant.
Check in with your doctor if you’re already on Wegovy and are planning to get pregnant at some point soon.
When to stop Wegovy before pregnancy
You should stop taking Wegovy at least two months before you start trying for a baby.
This is so the medicine has enough time to leave your system before you get pregnant. It can take at least five weeks for most of it to get flushed out.
Can you use Wegovy whilst breastfeeding?
We don’t know enough about how Wegovy affects breastmilk to recommend it here, either.
There’s limited research looking into whether Wegovy comes out in breast milk. In one study, eight mothers took Wegovy injections and had their breast milk analysed: once right after the injection, then again 12 and 24 hours later. No detectable levels of Wegovy were found.
Though animal studies show that Wegovy was present in the breast milk of lactating rats. So, the FDA product label notes ,that means it’s a possibility that Wegovy could come out in human milk, too.
All in all, this isn’t strong enough evidence to say that Wegovy won’t cause any harm while breastfeeding. That’s why it’s currently not advised.
It’s best not to try to actively lose weight while you’re breastfeeding to avoid any effects on milk production and its nutrient composition.
Does Wegovy affect birth control pills?
It’s thought that Wegovy’s effect on the gut—it slows digestion, which helps you feel full— may also prevent your body from properly absorbing birth control pills.
However, we don’t fully know how Wegovy affects contraception. So follow your provider’s advice on this one.
Officially, the FDA’s product label for Wegovy acknowledges that it’s possible the medicine could reduce the effectiveness of oral tablets. But, it notes, Wegovy hasn’t been shown to affect how well the combined pill was absorbed.
The UK label doesn’t say anything about contraception, other than you should take it to prevent pregnancy (as we don’t know if Wegovy is safe for unborn babies).
But what does the science say? Well, there’s not much of it. One study of 43 postmenopausal women with type 2 diabetes found that Wegovy didn’t reduce how well the combined pill could be absorbed. This suggests that it’s unlikely Wegovy would interfere with the effects of birth control pills, the authors note.
Though other possible side effects of slowed digestion are vomiting and diarrhoea, which may reduce the efficacy of the pill. If you’re sick less than 3 hours after taking the pill, take another one right away (then take the next one at your regular time). And if you’re still sick after that, or if you have diarrhoea that lasts for more than 24 hours, take your pill as normal alongside condoms or dental dams until a week after your symptoms clear.
At Voy, we advise Wegovy users to use a barrier method of contraception (such as condoms) even if they’re on the pill.
Wegovy and PCOS (polycystic ovary syndrome)
Did you know that Wegovy can have health benefits beyond weight loss? Yep—it’s been shown to help ease symptoms of PCOS, a condition where people assigned female at birth have too many “male” hormones and do not ovulate regularly or have regular periods. Insulin resistance (where you’re less sensitive to the effects of insulin) is a common feature of PCOS, too.
Both of these factors contribute to weight gain. And this can create a vicious cycle: when weight goes up, insulin resistance gets worse (we’ve explained why here), which can cause androgen levels to increase. And both of these changes can then bring on more weight gain…and so on.
But the increase in male hormones (aka androgens) can also aggravate PCOS symptoms like acne, irregular periods, and increased body hair growth.
Wegovy can lessen these effects by helping with weight loss. This can slow or stop the cycle, lowering androgens and improving insulin resistance. Studies have shown that losing just 5% of your starting weight could reduce PCOS symptoms.
Mounjaro might be able to help with PCOS, too.
Wegovy and the menstrual cycle
Could Wegovy mess with your period? Possibly, but not in the way you think.
If you have PCOS, Wegovy could actually have a positive effect. Recall that irregular periods are a symptom of high androgen levels, and that Wegovy can lower them by helping with weight loss. In one study, 80% of people with PCOS taking Wegovy found that their cycles became regular again.
But otherwise, as far as we know, Wegovy’s side effects don’t include any direct impacts on your period.
However, weight loss might. If you lose a lot of weight over a short time, your period can become irregular or even stop. See your doctor if you don’t have a period for three months or more. Usually though, when used as part of a weight loss programme, Wegovy brings on gradual, sustainable weight loss.
And in some cases, getting to a healthier weight can help your cycle become more regular.
Is Wegovy right for you?
If you aren’t breastfeeding or planning to have children in the near future, Wegovy might be an option. It works very well: people taking it could lose around 15% of their initial weight after a year.
But medicine isn’t the only factor in a successful weight loss plan. Having a healthy diet and moving your body regularly are essential, too. And here, getting personalised guidance matters because everyone’s journey is different.
That’s why our weight loss programme includes one-to-one support from expert coaches, who will be right here with you, answering your questions and cheering you on. You’ll also get weight loss medication posted to you each month.
Check if you’re eligible by filling out this short form, it won’t take more than a few minutes. Our clinicians will review it and come back to you right away.
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³Diab, Hanin, et al. “Subcutaneous Semaglutide During Breastfeeding: Infant Safety Regarding Drug Transfer into Human Milk.” Nutrients, vol. 16, no. 17, 2024: 2886 www.mdpi.com/2072-6643/16/17/2886.
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⁸“Pregnancy Guide: Overweight and Pregnancy.” NHS Wales, 2023, 111.wales.nhs.uk/livewell/pregnancy/ExistingHealthproblemsOverweight/ Accessed 29 January 2025.
⁹Skov, Kenneth, et al. “Semaglutide and Pregnancy.” International Journal of Gynecology & Obstetrics, vol. 163, issue 2, 2023: 699-700. obgyn.onlinelibrary.wiley.com/doi/10.1002/ijgo.15092.
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¹⁴“What to Do if You’re Sick or Have Diarrhoea When Taking the Combined Pill.” NHS, 2024 www.nhs.uk/contraception/methods-of-contraception/combined-pill/sickness-or-diarrhoea/ Accessed 29 January 2025.
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