GLP-1 and GIP Medicines: Weight Loss, Fertility, and the Surprising Rise in Pregnancies

Educational blog — Murrays Chemist, Harrow

Modern hormone-based injectable treatments used for weight management have transformed metabolic care across the UK. Alongside impressive improvements in weight, blood sugar, and appetite regulation, many people have noticed something unexpected — a rise in fertility and more unplanned pregnancies.

At Murrays Chemist, we see this trend frequently among patients using GLP-1 and GIP–based therapies as part of a structured, clinically supervised programme.
This blog explains why fertility improves, why these medicines must not be used during pregnancy, and how to stay safe while on treatment.

Why fertility can increase on GLP-1 and GIP treatments

These treatments work by mimicking naturally occurring hormones involved in appetite control, digestion, and glucose regulation. As people lose weight and their metabolic health improves, the body’s hormone balance often shifts in a healthier direction — and fertility follows.

In women

Weight loss can help restore normal reproductive function, especially in women with conditions like PCOS.
Benefits may include:

• More regular ovulation

• Lower insulin and androgen levels

• Reduced inflammation

• Improved egg quality and uterine conditions

In men

Improved weight and metabolic function may support:

• Higher testosterone levels

• Better sperm quality

• Increased libido and energy

• Better sleep and reduced inflammation

Because fertility can return suddenly — even after years of difficulty — unexpected pregnancies are increasingly common.

Why these treatments must not be used during pregnancy

These medicines are strictly contraindicated during pregnancy and breastfeeding.

Animal studies have shown potential risks, including:

• Pregnancy loss

• Foetal malformations

• Growth restriction

• Nutrient-transfer problems

• Low birth weight due to continued maternal weight loss

The medicines also slow digestion, which may affect nutrient absorption.

Due to these concerns, regulatory bodies recommend:

Stopping treatment at least 2 months before trying to conceive.

This allows the medication to fully leave the body.

Why contraception is essential during treatment

Because fertility can improve significantly, reliable contraception is crucial for anyone not planning a pregnancy.

Recommended contraception

Most reliable:

• Contraceptive implant

• Contraceptive injection

• Intrauterine device (IUD or IUS)

Oral contraception:
Still effective, but absorption may be delayed during dose changes or if vomiting occurs.
A backup barrier method is recommended for four weeks after any dose escalation or if gastrointestinal symptoms occur.

If you intend to conceive, speak to a clinician to plan a safe stop and washout period.

What to do if you become pregnant while using these treatments

• Stop the medicine immediately.

• Contact your prescriber or GP.

• Do not restart during pregnancy or breastfeeding.

While animal data suggests risk, many human pregnancies have been uncomplicated.
However, professional monitoring is essential.

Common Questions Answered

1. Can these treatments improve fertility?

Yes. Weight loss, reduced insulin resistance, and hormonal rebalancing can improve natural fertility in both men and women.

2. I have PCOS — can this support my fertility long term?

These treatments may improve ovulation patterns and metabolic markers used in PCOS management, but they must not be used while trying to conceive.

3. Can I use these medicines during pregnancy or breastfeeding?

No — they should be stopped well before conception and avoided throughout pregnancy and breastfeeding.

4. What if I used it before knowing I was pregnant?

Stop immediately and arrange a clinical review.
Many early exposures are not harmful, but monitoring is needed.

5. Does this guidance apply to all GLP-1 and GIP medicines?

Yes — the pregnancy precautions apply across the entire class of GLP-1/GIP-based weight-management therapies.

Balancing benefits with safety

These medicines can offer major improvements in metabolic health, cardiovascular risk, appetite control, and long-term weight management.
However, because they can dramatically improve fertility, family-planning advice and safe prescribing are essential.

At Murrays Chemist, we provide:

• Face-to-face clinical assessments

• Contraception and fertility counselling

• Regular monitoring

• Safety-first prescribing

• Support with stopping and restarting treatment where appropriate

Our goal is to ensure your treatment is effective, responsible, and aligned with your long-term health plans.

Key Takeaways

• GLP-1 and GIP treatments can significantly increase fertility.

• They must never be used during pregnancy or breastfeeding.

• Effective contraception is essential for anyone not planning a pregnancy.

• A two-month washout is required before trying to conceive.

• Speak to a clinician before stopping, starting, or switching treatment.