Can You Become Pregnant While Using Weight-Loss Injections?

It is possible to become pregnant while using weight-loss injections. Medicines used for weight management, such as semaglutide, liraglutide and tirzepatide, are not contraceptive methods and do not prevent pregnancy. Pregnancy may occur when effective contraception is not used or when the method being used is disrupted.

However, continuing these medicines for weight-loss purposes during pregnancy is not recommended. Current product information states that weight loss during pregnancy offers no expected benefit to the mother or baby and that potential risks to the fetus cannot be fully excluded. Human pregnancy data for semaglutide and tirzepatide remain limited, and current warnings are largely based on animal studies and the medicines’ mechanisms of action.

When pregnancy is recognised, it is not appropriate to continue the medicine, change the dose or switch to another weight-loss medicine without medical guidance. The prescribing physician and an obstetrician and gynaecologist should be contacted promptly to create an individual plan.

Do Weight-Loss Injections Prevent Pregnancy?

Weight-loss injections do not have a contraceptive effect. These medicines may affect appetite, fullness, gastric emptying and blood glucose control, but they cannot be used as a reliable method of preventing ovulation or pregnancy.

Irregular periods also do not mean that pregnancy cannot occur. Ovulation may be difficult to predict in people with polycystic ovary syndrome, insulin resistance or weight changes. A person should therefore not rely only on their menstrual pattern when there is a delayed period, unprotected sexual intercourse or symptoms of pregnancy.

When pregnancy is not planned, the contraceptive method should be selected with an obstetrician and gynaecologist, taking into account the weight-loss injection, other medicines, age, smoking, migraine, clotting history and individual health.

Do Weight-Loss Injections Increase Fertility?

Weight-loss injections are not direct fertility treatments. However, weight loss, changes in insulin sensitivity and improved menstrual regularity may alter the likelihood of pregnancy in some people. Pregnancy may therefore occur even in someone who previously had irregular periods or believed that they could not become pregnant.

Data on the direct effects of these medicines on human fertility are limited. Current tirzepatide product information states that its effect on human fertility is unknown. Pregnancy should therefore not be assumed to be impossible during treatment.

People who are not planning pregnancy should review their contraceptive method at the beginning of treatment. Those who want to become pregnant should plan when to stop the medicine and their pre-pregnancy health goals with their treating physicians.

Can Weight-Loss Injections Affect The Contraceptive Pill?

The answer may differ according to the weight-loss injection being used. GLP-1- and GLP-1/GIP-based medicines may slow gastric emptying and affect the absorption rate of certain oral medicines. The degree of this effect is not the same for every medicine.

Current Mounjaro product information published in Türkiye in March 2026 states that after a single dose of tirzepatide, the peak levels and overall exposure of certain components of a combined oral contraceptive decreased. However, the change was not considered clinically meaningful and no dose adjustment was required.

In contrast, the February 2026 Zepbound product information from the U.S. Food and Drug Administration advises people using oral hormonal contraception to switch to a non-oral method or add a barrier method for four weeks after starting tirzepatide and for four weeks after every dose escalation. Because product and national instructions may differ, the current instructions for the specific product should be followed and contraception should be discussed with a physician.

Liraglutide product information states that no clinically meaningful change in the effectiveness of the oral contraceptive pill is expected. However, severe vomiting or diarrhoea may reduce the absorption and protection provided by an oral contraceptive.

Can Vomiting And Diarrhoea Affect Contraception?

Weight-loss injections may cause nausea, vomiting and diarrhoea, particularly at the beginning of treatment or after a dose increase. Vomiting shortly after taking an oral contraceptive pill or experiencing prolonged severe diarrhoea may prevent the medicine from being absorbed adequately.

In this situation, the “missed pill”, “vomiting” and “severe diarrhoea” recommendations in the contraceptive pill’s own instructions should be followed. Advice from a pharmacist or obstetrician and gynaecologist may be needed.

During vomiting and diarrhoea, attention should be paid not only to contraception but also to dehydration. A routine appointment should not be awaited when fluids cannot be consumed, urine output decreases or marked dizziness or faintness develops.

Is A Pregnancy Test Needed During Weight-Loss Injection Treatment?

There is no single general rule requiring everyone using a weight-loss injection to have pregnancy tests at fixed intervals. However, a test may be considered when pregnancy is possible, a period is delayed or there has been a problem with contraception.

A pregnancy test may particularly be considered when:

• A period does not begin when expected

• Unprotected sexual intercourse occurs

• An oral contraceptive pill is missed

• Vomiting or severe diarrhoea occurs after taking the pill

• Breast tenderness, nausea or unusual fatigue develops

• Pregnancy is being planned

• A new weight-loss medicine will be started

• The contraceptive method is changed

If an early test is negative but the period does not begin, the test may need to be repeated at an appropriate time or a healthcare professional may need to be consulted.

What Should Be Done If Pregnancy Is Discovered During Treatment?

When a pregnancy test is positive or pregnancy is suspected, the prescribing physician and an obstetrician and gynaecologist should be contacted promptly. Product information for semaglutide and tirzepatide used for weight management recommends discontinuing treatment when pregnancy is recognised.

Receiving one or more doses before pregnancy is discovered does not by itself mean that the pregnancy has definitely been harmed. Human pregnancy data are insufficient to establish a precise level of risk. Rather than reacting in panic, the following information should be shared with the physician:

• Name and active ingredient of the medicine

• Dose used

• Date of the most recent dose

• Date treatment began

• Date of the last menstrual period

• Date of the pregnancy test

• Other medicines and supplements

• Diabetes and other chronic conditions

• Symptoms such as nausea, vomiting, bleeding or pain

The physician may create an appropriate monitoring plan based on the gestational age, medicine and other risks. Decisions concerning the pregnancy should not be based only on information found online.

Can Weight-Loss Injections Harm The Baby?

Human data on the use of semaglutide, liraglutide and tirzepatide during pregnancy are limited. These medicines therefore cannot be considered completely safe in pregnancy. Product information for semaglutide and tirzepatide reports reproductive toxicity and adverse fetal-development findings in animal studies and does not recommend their use for weight management during pregnancy.

Limited evidence also does not mean that every baby exposed accidentally during pregnancy will be harmed. Individual risk should be assessed according to the medicine, dose, duration of exposure, gestational age and maternal health conditions.

High blood glucose, uncontrolled diabetes, inadequate nutrition and severe vomiting may also affect maternal and fetal health. The overall health condition and all medicines should therefore be assessed rather than focusing only on the weight-loss injection.

When Should The Medicine Be Stopped Before A Planned Pregnancy?

The time needed for weight-loss injections to leave the body differs according to the active ingredient. The recommended interval before pregnancy is therefore not the same for every medicine.

According to current product information:

• Semaglutide: Discontinuation at least two months before a planned pregnancy is recommended because of its long half-life.

• Tirzepatide: The Turkish product information published in March 2026 recommends discontinuation at least one month before a planned pregnancy.

• Liraglutide: Use is not recommended in people who are pregnant, think they may be pregnant or are planning pregnancy. The stopping time should be determined by the physician according to the individual treatment plan.

Pregnancy plans should therefore be shared with the physician in advance whenever possible. The medicine should not be stopped suddenly without a plan, particularly when it is also being used for diabetes, as a pregnancy-compatible strategy is needed to maintain blood glucose control.

Can Pregnancy Be Attempted Immediately After Stopping The Medicine?

The appropriate time to begin trying for pregnancy after stopping treatment depends on the active ingredient and the person’s health. The recommended medicine-free interval of at least two months for semaglutide and at least one month for tirzepatide reflects the time these substances take to leave the body.

During this period, the physician may plan whether contraception should continue, folic acid use, changes to diabetes medicines, thyroid testing and other pre-pregnancy assessments.

A person does not necessarily need to complete every weight-loss goal before planning pregnancy. The pre-pregnancy aim is not only to reach a certain weight but also to manage blood glucose, blood pressure, nutrition and medicines as safely as possible.

What Should People With Diabetes Do After Stopping The Medicine?

When the weight-loss injection is also part of type 2 diabetes treatment, pregnancy planning requires additional care. Blood glucose may rise again after the medicine is stopped. Uncontrolled blood glucose may also create important pregnancy-related risks.

Diabetes medicine should therefore not be stopped without medical guidance or replaced randomly with another treatment. Endocrinology and obstetrics and gynaecology specialists may assess:

• Fasting and post-meal blood glucose

• HbA1c

• Other diabetes medicines

• History of hypoglycaemia

• Kidney and liver function

• Diabetic eye and kidney complications

• Pre-pregnancy eating pattern

• Individual blood glucose targets

Rapid contact with the healthcare team is important when pregnancy is recognised so that blood glucose treatment is not interrupted.

Can Emergency Contraception Be Used During Treatment?

Emergency contraception may be needed after unprotected sexual intercourse, condom failure or disruption of the usual contraceptive method. The choice of method may depend on the time elapsed, body weight, the weight-loss injection, other medicines and individual health.

Because weight-loss injections may slow gastric emptying and cause vomiting, this should be considered when assessing oral emergency contraception. People using tirzepatide or experiencing significant vomiting should tell the pharmacist or obstetrician and gynaecologist the name of the medicine they use.

Timing is important in emergency contraception. A routine appointment should not be awaited after unprotected intercourse, and advice should be obtained from a healthcare professional on the same day.

Do Weight-Loss Injections Cause Ectopic Pregnancy?

There is no conclusive evidence that weight-loss injections directly cause ectopic pregnancy. However, severe one-sided pelvic pain, shoulder pain, vaginal bleeding, marked dizziness or fainting in a person with a positive pregnancy test may require urgent assessment for conditions such as ectopic pregnancy.

An online consultation or routine examination should not be awaited when these symptoms occur. Emergency services should be contacted or the nearest emergency department should be visited.

Should Weight Loss Continue During Pregnancy?

Pregnancy is not a period in which active weight-loss treatment should continue. Current semaglutide product information states that weight loss during pregnancy offers no benefit and may cause fetal harm. Appropriate weight change during pregnancy should be assessed by an obstetrician and gynaecologist according to pre-pregnancy body mass index and maternal health.

Very-low-calorie diets, prolonged fasting, highly restrictive eating and unsupervised supplements during pregnancy may make it difficult to meet the nutritional needs of the mother and baby.

Having overweight or obesity does not make nutritional support unnecessary during pregnancy. The goal should be to obtain sufficient protein, vitamins, minerals and energy and to monitor health values such as blood glucose and blood pressure rather than aiming for rapid weight loss.

Can Weight-Loss Injections Be Used While Breastfeeding?

The use of weight-loss injections during breastfeeding should be assessed separately according to the active ingredient. There are insufficient data on the amount of injected semaglutide in human milk, its effects on the breastfed infant or its effects on milk production. Current product information recommends considering the benefits of breastfeeding together with the mother’s clinical need for treatment.

It is also not known with certainty whether tirzepatide passes into human milk. Current Turkish product information states that the benefits of breastfeeding for the child and the benefits of treatment for the mother should be considered when deciding whether to interrupt breastfeeding or avoid treatment.

A weight-loss injection should therefore not be restarted automatically after birth. Breastfeeding, postpartum nutritional needs, diabetes control and other medicines should be assessed together by a physician.

When Can Treatment Restart After Pregnancy?

The appropriate time to restart treatment after birth is not the same for everyone. The method of delivery, recovery, breastfeeding, blood loss, nutrition, diabetes control and other medicines should be considered.

Unsupervised use of appetite-reducing medicines and very-low-calorie diets for rapid postpartum weight loss may increase the risk of fatigue, muscle loss, milk-supply problems and nutritional deficiency.

When restarting treatment is being considered, an assessment by obstetrics and gynaecology, endocrinology and, when necessary, a dietitian should be obtained. Restarting directly at the previous dose may not be appropriate; the dose plan should be determined by the prescribing physician.

Which Symptoms Require Medical Assessment?

The following symptoms require prompt assessment in people who may be pregnant or have a positive pregnancy test while using a weight-loss injection:

• Severe or one-sided pelvic pain

• Vaginal bleeding

• Pain radiating to the shoulder

• Fainting or marked dizziness

• Severe and persistent abdominal pain

• Abdominal pain radiating to the back

• Recurrent or persistent vomiting

• Inability to consume fluids

• A significant reduction in urine output

• Severe symptoms of hypoglycaemia

• Significant shortness of breath

• Altered consciousness

• Rapidly worsening general health

In cases of severe abdominal or pelvic pain, heavy bleeding, fainting, altered consciousness, seizure or significant shortness of breath, an online consultation should not be awaited. Emergency services should be contacted or the nearest emergency department should be visited.

This content is provided for general informational purposes. Decisions concerning weight-loss injections, contraception, pregnancy planning, discontinuation and breastfeeding require an individual medical assessment.

Plan Your Online Obstetrics And Gynaecology Doctor Consultation With Happ Health

With the “Health Everywhere, For Everyone, Always.” approach, we believe that pregnancy risk during weight-loss injection treatment should be assessed not only according to menstrual regularity but also together with the medicine used, contraceptive method, pregnancy plans, existing conditions and other treatments.

By planning an Online Obstetrics And Gynaecology Doctor consultation through Happ Health, you can have your weight-loss injection, contraceptive method, menstrual pattern, pregnancy plans and any pregnancy test results assessed. An obstetrician and gynaecologist may provide guidance on choosing an appropriate contraceptive method, planning pre-pregnancy preparation or determining the next steps when pregnancy is suspected.

Preparing the date of your last menstrual period, the name of the medicine and date of the most recent dose, contraceptive method, pregnancy-test results, recent laboratory results and a list of other medicines before the online consultation may make the assessment easier. When a physical examination, ultrasound, blood test or in-person pregnancy assessment is needed, you may be referred to a healthcare institution.

In cases of severe pelvic or abdominal pain, heavy vaginal bleeding, shoulder pain, fainting, recurrent vomiting, inability to consume fluids, altered consciousness or rapidly worsening general health, an online follow-up should not be awaited and urgent medical assessment should be obtained.

References

• Turkish Medicines And Medical Devices Agency, Wegovy Summary Of Product Characteristics:
  https://www.titck.gov.tr/storage/Archive/2025/kubKtAttachments/WEGOVY0.5KB_17_02_2025.pdf

• Turkish Medicines And Medical Devices Agency, Saxenda Summary Of Product Characteristics:
  https://www.titck.gov.tr/storage/Archive/2025/kubKtAttachments/saxendakubtemiz_10_03_2025.pdf

• Turkish Medicines And Medical Devices Agency, Mounjaro Summary Of Product Characteristics:
  https://www.titck.gov.tr/storage/Archive/2026/kubKtAttachments/15YAYINLANACAKkb_12_03_2026.pdf

• U.S. Food And Drug Administration, Current Wegovy Prescribing Information:
  https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/215256s026lbl.pdf

• U.S. Food And Drug Administration, Current Zepbound Prescribing Information:
  https://www.accessdata.fda.gov/drugsatfda_docs/label/2026/217806s042lbl.pdf

• European Medicines Agency, Mounjaro Product Information:
  https://www.ema.europa.eu/en/documents/product-information/mounjaro-epar-product-information_en.pdf

• European Medicines Agency, Saxenda Product Information:
  https://www.ema.europa.eu/en/documents/product-information/saxenda-epar-product-information_en.pdf