What women need to know about GLP-1 medications, pregnancy planning and contraception
Illustration of a medicine review before pregnancy. AI-generated editorial artwork; not a real patient.
Pregnant, planning a baby, or relying on the contraceptive pill? Understand the important precautions before your next weight-loss injection.
Australia's medicines regulator advises that GLP-1 medicines should not be used during pregnancy. This includes semaglutide, found in Ozempic and Wegovy, and tirzepatide, found in Mounjaro, which acts on both GIP and GLP-1 receptors.
For women taking these medications, pregnancy planning and effective contraception should be part of every treatment discussion.
If you have already taken one of these medications before discovering you are pregnant, seek medical advice promptly. Accidental early exposure does not automatically mean your baby has been harmed.
Plan Before You Try for a Baby
GLP-1 medications can remain in the body for some time after the last injection. Australian product information specifies different minimum waiting periods before attempting pregnancy.
It is important to discuss when to stop treatment and whether alternative medication is needed, particularly if you are taking these medicines to manage diabetes. Your prescriber can help establish a safe treatment transition.
[IMAGE: Pregnancy planning and medication timeline]
Minimum waiting periods from Australian product information. Maintain effective contraception during the washout period and confirm your individual plan with your clinician.
Missing one weekly injection does not mean the medication has cleared your system. The recommended waiting period depends on the specific medicine.
Why the Pregnancy Warning Matters
Animal studies have raised concerns about potential effects on pregnancy and fetal development.
Ozempic product information describes reproductive toxicity in animal studies. Mounjaro information also reports fetal growth impairment and abnormalities, alongside maternal toxicity.
These findings justify caution, but animal studies cannot predict the outcome of an individual human pregnancy.
The clinical message is clear: these medications should not be used during pregnancy. However, it is equally important not to assume that every pregnancy involving accidental exposure will result in harm.
Women who discover they are pregnant while taking these medications should receive prompt, individualised medical advice.
What Human Evidence Can Tell Us
An Australian report reviewed 13 pregnancies involving first-trimester exposure to semaglutide. However, its small sample size and retrospective design limit the conclusions that can be drawn.
Small studies cannot reliably rule out uncommon risks or establish the safety of continued treatment throughout pregnancy.
Current UK pregnancy medicine guidance is reassuring regarding inadvertent early exposure, generally recommending that treatment be stopped once pregnancy is identified.
However, it continues to advise against using these medications during pregnancy and acknowledges uncertainty about exposure later in pregnancy.
The important distinction is that reassuring findings following accidental early exposure should support calm, informed counselling, not continued medication use during pregnancy.
Mounjaro and the Contraceptive Pill
Mounjaro carries an additional precaution for women using oral hormonal contraception.
Because tirzepatide delays stomach emptying, reduced effectiveness of oral hormonal contraceptives cannot be excluded.
The Australian Therapeutic Goods Administration (TGA) advises women using oral hormonal contraception to either:
- Switch to a non-oral contraceptive method; or
- Add a barrier method, such as condoms.
These additional precautions should continue for four weeks after starting Mounjaro and for four weeks after every dose increase.
FOUR WEEKS after starting treatment | FOUR WEEKS after every dose increase
When doses are increased repeatedly, these precautionary periods may overlap. Ask your pharmacist to help you understand the timing and discuss suitable contraceptive options.
It is important not to assume that all weight-loss medications have the same contraceptive interactions.
Specialist guidance reports no evidence that semaglutide itself reduces the effectiveness of oral contraceptives. However, vomiting or severe diarrhoea can affect pill absorption. Women experiencing these symptoms should follow their contraceptive pill instructions and seek prompt advice if needed.
A Positive Pregnancy Test Needs a Prompt Plan
If you discover you are pregnant while taking Ozempic or Mounjaro, there are several important steps to take.
1. Contact Your Prescriber Promptly
Product information advises discontinuing semaglutide or tirzepatide when pregnancy occurs.
Do not continue taking these medications for weight management while waiting for a routine appointment. Contact your prescribing clinician for advice.
2. Protect Your Diabetes Control
If you are taking the medication to manage diabetes, arrange an alternative treatment plan urgently.
Do not stop insulin or other prescribed diabetes medications without medical advice. Poorly controlled diabetes can also pose risks during pregnancy, making appropriate treatment and monitoring essential.
3. Record Your Medication Exposure
Provide your healthcare professional with the following information:
- The medication name.
- Your current dose.
- The date of your last injection.
- The estimated date of conception or pregnancy dates, if known.
These details help your clinician assess your individual circumstances and recommend appropriate care.
4. Arrange Appropriate Antenatal Care
Early exposure to a GLP-1 medication does not automatically mean additional scans for major birth defects are necessary under current UK guidance.
However, diabetes, BMI and other individual clinical factors may require closer monitoring.
Your maternity team should determine the appropriate antenatal care and monitoring for your circumstances.
Health Education Must Accompany Treatment
Women deserve an informed conversation about pregnancy intentions, contraception and treatment transitions before receiving their first prescription.
The Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG) highlights the importance of preconception counselling and considering alternative strategies for metabolic health.
At Weight Loss for Life, I have always advocated practical food education, informed choices and a better understanding of long-term health.
During pregnancy, intentional weight loss is not recommended. The focus should be on appropriate nutrition, physical activity and supporting maternal and baby health under professional clinical guidance.
A commercial weight-loss program should never replace appropriate antenatal care.
Before your next prescription, ask your healthcare professional to explain your pregnancy prevention or pregnancy planning arrangements. Write down the agreed plan and keep it with your medication information.
Women should never have to navigate these decisions without clear information and appropriate medical support.
Sources and Further Reading
The following references support the medical information discussed in this article. Australian product information should guide local prescribing decisions. Always check the latest product information with your pharmacist or prescribing clinician.
Sources checked 8 November 2026.
1. Therapeutic Goods Administration (TGA)
Updated contraception advice for Mounjaro (tirzepatide).
2. Australian Medicine Information
Ozempic – Product and Consumer Information.
3. Australian Medicine Information
Mounjaro – Product and Consumer Information.
4. UK Teratology Information Service (UKTIS) – BUMPS
GLP-1 Receptor Agonists – September 2026.
5. NHS Specialist Pharmacy Service
Considerations and Interactions with GLP-1 Receptor Agonists.
6. Morton A and He J
Pregnancy Outcomes Following First Trimester Exposure to Semaglutide. Obstetric Medicine, published online 2025.
7. Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG)
GLP-1 Receptor Agonists in Women's Health: Key Clinical Considerations – July 2026.
Medical disclaimer: This article is intended for general educational purposes only. It does not provide individual medical advice, diagnose fetal harm or replace consultation with a qualified healthcare professional. Pregnancy exposure, medication decisions and diabetes treatment require advice from the prescribing clinician and maternity team.
Image disclaimer: AI-generated editorial artwork is used for illustration only and does not depict a real patient or medical evidence.