GLP-1 and GIP Medications: Weight Loss, Fertility, and the Surprising “Baby Boom” Effect

Medications such as semaglutide (Wegovy, Ozempic) and tirzepatide (Mounjaro) have transformed weight management across the UK. Beyond impressive weight loss results, many people are noticing something unexpected — a rise in fertility and surprise pregnancies.

At Murrays Chemist, we’ve seen this trend first-hand in patients using GLP-1 and GIP-based treatments. Let’s explore why this happens, what the risks are, and how to stay safe if you’re using these injections.

Why fertility can increase on GLP-1 and GIP injections

GLP-1 and GIP are hormones that help regulate appetite, digestion, and blood sugar levels. These new weight loss medications mimic those natural hormones, helping patients eat less, lose fat, and improve metabolic health.

But as the body’s weight and hormone balance improve, fertility often follows.

For women

• Weight loss helps restore regular ovulation, especially for those with polycystic ovary syndrome (PCOS) — a common cause of infertility, particularly among South Asian women.

• Lower insulin and androgen levels make menstrual cycles more predictable.

• Inflammation and excess body fat reduce, improving egg quality and uterine health.

For men

• Weight loss boosts testosterone, sperm quality, and libido.

• Better metabolic control and improved sleep support fertility and energy.

It’s no coincidence many couples using these medications suddenly find themselves expecting — sometimes unexpectedly.

Why pregnancy while on GLP-1 or GIP medication is unsafe

These medicines are not approved for use during pregnancy or breastfeeding.
Research from animal studies has shown possible risks to the developing baby, including:

• Miscarriage or early pregnancy loss

• Foetal malformations (particularly of the skeleton and organs)

• Poor foetal growth due to altered nutrient and glucose balance

• Low birth weight if the mother continues rapid weight loss during pregnancy

The medications also slow digestion, which may affect nutrient absorption and the baby’s development.

Because of this, manufacturers and health regulators recommend that women stop these treatments at least two months before trying to conceive to ensure the medication has fully cleared from the body.

Why contraception is essential

As weight loss and hormone levels normalise, fertility can return quickly — even if it’s been absent for years. That’s why reliable contraception is vital for anyone using GLP-1 or GIP injections.

Best contraception options

• Implant, injection, or intrauterine device (IUD) – highly effective and not affected by delayed stomach emptying.

• Oral contraception can still be used, but absorption might be delayed during dose changes or if you experience vomiting. Always use a backup method (condoms) for four weeks after each dose escalation.

If you’re planning a pregnancy soon, speak to your clinician before starting or continuing treatment — they’ll help plan a safe stop and washout period.

What to do if you become pregnant while on treatment

1. Stop the medication immediately.

2. Contact your prescriber or GP as soon as possible.

3. Do not restart after pregnancy or while breastfeeding unless advised by your healthcare professional.

4. Don’t panic — while animal data suggests risk, many reported human pregnancies have been fine, but close monitoring is always necessary.

Common Questions Answered

1. Can these medications really improve fertility?

Yes — by helping with weight loss, improving insulin sensitivity, and restoring ovulation, they can naturally increase fertility in both men and women.

2. I have PCOS. Will this help me conceive?

GLP-1 treatments can improve ovulation and hormonal balance in PCOS, but you must not use them while trying to conceive. They’re most effective as a pre-conception treatment under supervision.

3. Can I use GLP-1 or GIP medication while pregnant or breastfeeding?

No. They should be stopped at least two months before pregnancy and avoided while breastfeeding.

4. What happens if I accidentally take it during early pregnancy?

Stop immediately, contact your prescriber, and arrange monitoring. Most early exposures don’t cause immediate harm, but you’ll need follow-up and support.

5. Does this apply to Mounjaro and Wegovy?

Yes — the same pregnancy and contraception advice applies to semaglutide (Ozempic/Wegovy) and tirzepatide (Mounjaro).

Balancing the benefits with safety

GLP-1 and GIP-based medications are powerful tools for managing weight, improving heart and metabolic health, and reducing diabetes risk. But as fertility improves, careful planning becomes essential.

At Murrays Chemist, our prescribing clinicians take a holistic approach — considering your medical background, fertility goals, and future plans before starting treatment. We’ll guide you through safe use, monitoring, and contraception options to ensure treatment remains effective and responsible.

In summary

• GLP-1 and GIP medications can dramatically improve fertility.

• They must never be used during pregnancy or breastfeeding.

• Always use reliable contraception during treatment.

• Plan a two-month washout before trying to conceive.

• Speak to a clinician before making any medication changes.