Guide · Updated November 2026
Do GLP-1s Affect Fertility? The Ozempic Baby Phenomenon
GLP-1 receptor agonists like semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro, Zepbound) have been linked in news reports to unexpected pregnancies, especially in women with PCOS. The likely main reason is weight loss restoring ovulation, not a direct fertility drug effect. These drugs should not be used during pregnancy, and tirzepatide can make birth control pills less reliable.
The term “Ozempic babies” took off on social media and in the news in 2024. Women on GLP-1 medications for weight loss or diabetes have described pregnancies they did not expect.
But no large GLP-1 trial was designed to test fertility. Semaglutide and tirzepatide are GLP-1 receptor agonists that slow gastric emptying, reduce appetite, and improve insulin sensitivity. They were built for blood sugar control and weight loss, not reproduction. The fertility connection most likely comes from the weight loss and metabolic changes, and for women with conditions like PCOS, that can matter a lot.
I have been on Mounjaro for over a year tracking my body composition with DEXA scans, so I follow the research closely. This guide covers what the data actually says, what the FDA recommends, and what you should know about contraception if you are on a GLP-1.
How GLP-1 Medications Can Restore Fertility
The connection between GLP-1 fertility and unexpected pregnancies is not magic. It comes down to biology.
Weight Loss and Ovulation
This is likely the biggest factor. Modest weight loss can help restart ovulation in some women who had stopped ovulating because of excess weight or PCOS. In the STEP 1 trial, semaglutide 2.4 mg produced an average weight loss of 14.9% over 68 weeks. In SURMOUNT-1, tirzepatide 15 mg produced 20.9% average weight loss over 72 weeks.
A woman who loses a meaningful amount of weight on a GLP-1 could see her cycles change, sometimes within the first few months of treatment.
Insulin Resistance and Hormones
High insulin levels can drive extra testosterone production in the ovaries, which can suppress ovulation. GLP-1 medications lower blood sugar and insulin resistance, mostly through weight loss, which may help cycles return.
This is especially relevant for women with PCOS, a leading cause of anovulatory infertility. The WHO estimates PCOS affects 10 to 13% of women of reproductive age.
Direct Hormonal Effects
Some researchers think GLP-1 drugs may also affect reproductive hormones directly. The evidence for that is early and limited.
The PCOS Connection: Why It Matters Most
PCOS is at the center of the Ozempic baby phenomenon. The condition creates a vicious cycle: obesity worsens insulin resistance, high insulin drives androgen production, and excess androgens suppress ovulation.
GLP-1 medications break this cycle at multiple points:
- Weight loss, often in the double digits in the major trials
- Lower insulin resistance
- Possibly lower androgen levels
- Ovulation returning in some women who had not ovulated regularly
In one randomized trial of 176 overweight or obese women with PCOS (Clinical Endocrinology, 2017), the natural pregnancy rate was 43.6% with exenatide (an older GLP-1) versus 18.7% with metformin during the second 12 weeks of the study. The trial was small and open-label.
If you have PCOS and start a GLP-1, review your contraception plan with your prescriber before you start.
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Browse Provider Directory →What the Clinical Data Shows
No large trial has been designed to study GLP-1 fertility effects directly. The safety data on pregnancy comes from observational studies of women who were exposed early in pregnancy.
| Study | Year | Sample | Key Finding |
|---|---|---|---|
| Dao et al. (BMJ Open) | 2024 | Pregnancies exposed to GLP-1 drugs in the first trimester, from six teratology information services | Major birth defects 2.6% vs 2.3% in women with diabetes and 3.9% in women with overweight or obesity |
| Cesta et al. (JAMA Internal Medicine) | 2024 | Pregnant women with type 2 diabetes in Nordic, US and Israeli data | Relative risk of major malformations 0.95 for GLP-1 drugs compared with insulin |
These studies did not find a clear increase in major birth defects from early exposure. The samples are small, and the confidence intervals are wide.
No GLP-1 medication is approved for use during pregnancy. The Wegovy label and Zepbound label say these drugs may cause fetal harm and should be stopped when pregnancy is recognized.
GLP-1 Medications and Birth Control: A Real Problem
This is where things get practical, and where the distinction between semaglutide and tirzepatide matters.
Tirzepatide (Mounjaro/Zepbound): Confirmed Interaction
The Zepbound label warns that tirzepatide delays gastric emptying and can reduce how well oral medicines are absorbed, including oral hormonal contraceptives.
The label advises:
- Switch to a non-oral contraceptive method (IUD, implant, injection, patch), OR
- Add a barrier method (condoms) for 4 weeks after starting tirzepatide and 4 weeks after each dose increase
This is not theoretical. If you are on Mounjaro or Zepbound and relying solely on the pill, you may not be fully protected.
Semaglutide (Ozempic/Wegovy): No Confirmed Interaction
The Wegovy label does not carry the same oral contraceptive advice.
But the GI side effects still matter. If you vomit soon after taking your pill, that dose may not have been absorbed. Check your pill’s leaflet for what to do. If you are experiencing persistent nausea, vomiting, or diarrhea (which the side effects guide covers in detail), your oral contraceptive reliability drops regardless of which GLP-1 you are on.
What Actually Works
| Contraception Method | Affected by GLP-1 stomach effects? | Notes |
|---|---|---|
| Hormonal IUD (Mirena, etc.) | No | Not affected by GI issues |
| Copper IUD | No | Non-hormonal, not affected by GI issues |
| Implant (Nexplanon) | No | Bypasses GI tract entirely |
| Injectable (Depo-Provera) | No | Bypasses GI tract |
| Patch | No | Absorbed through skin, not GI |
| Oral contraceptive pill | Possibly | Reduced absorption possible with tirzepatide. GI side effects can reduce effectiveness on any GLP-1 |
| Condoms | No | Add to oral contraceptive if on tirzepatide during dose changes |
If you are starting a GLP-1 and do not want to get pregnant, talk to your doctor about switching to a non-oral method. This is the single most actionable piece of advice in this entire article.
When to Stop GLP-1s Before Trying to Conceive
If you are planning a pregnancy, timing your GLP-1 discontinuation matters.
Semaglutide: The Wegovy label says to stop at least 2 months before a planned pregnancy because of semaglutide’s long half-life. The label puts the half-life at about 1 week and says the drug stays in circulation for about 5 to 7 weeks after the last dose.
Tirzepatide: The US label does not give a washout period. UK government guidance says to stop at least 1 month before trying to get pregnant. The Zepbound label puts tirzepatide’s half-life at about 5 days.
If you are working with a fertility specialist, follow their timing for your situation.
What about the weight you have lost? The good news is that the metabolic benefits of weight loss do not disappear overnight. Weight regain is common after stopping, so plan with your doctor how to hold onto your progress. Our maintenance guide covers strategies for holding onto your progress after stopping.
Animal Studies: What They Show (and Don’t)
The Wegovy label reports embryo and fetal deaths, structural abnormalities, and growth changes in pregnant rats given semaglutide at clinically relevant exposures. In rabbits and monkeys, early pregnancy losses and abnormalities coincided with marked weight loss in the mothers. The label also says weight loss offers no benefit to a pregnant patient and may cause fetal harm.
That does not make GLP-1s safe during pregnancy. No one should stay on a GLP-1 during pregnancy unless their doctor specifically advises it.
If You Get Pregnant on a GLP-1: What to Do
First: do not panic. The studies we have so far (Dao 2024, Cesta 2024) have not found a clear increase in major birth defects from early exposure, though they are small.
Steps to take:
- Contact your prescriber right away. The Wegovy and Zepbound labels say to stop the drug when pregnancy is recognized. Do not take your next dose until you have spoken with them.
- Tell them your dates. Let them know when your last dose was and when you estimate conception occurred.
- See your OB/GYN. Make sure they know about the exposure. Novo Nordisk runs a Wegovy pregnancy exposure registry listed on the label.
- Do not restart until after delivery, and ask your doctor about breastfeeding. The Wegovy label says breastfeeding is not recommended during treatment with Wegovy tablets.
GLP-1 Fertility and Men
Most of the Ozempic baby conversation focuses on women, but men are not excluded. Obesity is linked to lower testosterone, reduced sperm quality, and erectile dysfunction. Weight loss may help with some of these, but this has not been well studied with GLP-1 drugs.
Weight loss in men with obesity may raise testosterone and improve sexual function.
That said, there is limited direct research on GLP-1 medications and male fertility specifically. The improvements are most likely driven by weight loss and improved body composition rather than the medication acting on reproductive hormones directly.
The Bottom Line
GLP-1 medications are not fertility drugs, but they can restore fertility that obesity and PCOS had suppressed. The Ozempic baby phenomenon is real, driven primarily by weight loss restarting ovulation. If you are on a GLP-1 and do not want to get pregnant, talk to your doctor about contraception, especially on tirzepatide. If you are trying to conceive, follow your label and your doctor on timing (at least 2 months for semaglutide). If you get pregnant unexpectedly, contact your prescriber right away. The early data on birth defects is reassuring but limited.
For help finding an affordable GLP-1 provider, check our provider comparison directory or start with the cheapest GLP-1 options guide.
FAQ
Can Ozempic help you get pregnant?
Ozempic (semaglutide) is not a fertility medication and is not FDA-approved for that purpose. However, the weight loss it produces may restore ovulation in some women whose fertility was suppressed by obesity or PCOS.
Should I stop Ozempic or Mounjaro before trying to conceive?
Yes. The Wegovy label says to stop semaglutide at least 2 months before a planned pregnancy. For tirzepatide, UK government guidance says at least 1 month. Talk to your doctor about timing based on your specific situation.
Does Mounjaro interfere with birth control pills?
Yes. Tirzepatide (the active ingredient in Mounjaro and Zepbound) can reduce oral contraceptive absorption by slowing gastric emptying. The label advises switching to a non-oral contraceptive or adding a barrier method for 4 weeks after starting and for 4 weeks after each dose increase.
Is it safe if I got pregnant while on a GLP-1?
Studies so far (Dao 2024, Cesta 2024) have not found a clear increase in major birth defects from early GLP-1 exposure, but they are small. Contact your prescriber right away. In the Dao study, the major birth defect rate was 2.6% in exposed pregnancies and 2.3% in pregnancies of women with diabetes.
Do GLP-1 medications affect male fertility?
There is limited direct research, but weight loss from GLP-1 medications can improve testosterone levels, sperm quality, and sexual function in men with obesity. These improvements are most likely driven by the weight loss itself rather than a direct drug effect on reproductive hormones.
What we checked
This AI-assisted public-source desk check reviewed the Wegovy and Zepbound labels on DailyMed, UK government guidance on GLP-1 medicines and pregnancy, the Dao 2024 and Cesta 2024 pregnancy studies, the 2017 exenatide PCOS trial, the WHO PCOS fact sheet, and the STEP 1 and SURMOUNT-1 trials on November 4, 2026. This is not a clinical review and it is not medical advice. Prices and policies change, so confirm them with the provider or your prescriber before you act.
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