WEIGHT LOSS & FERTILITY

As 2025 saw the use of weight-loss medications soar, one of the UK's leading fertility providers, Care Fertility, urges anyone using these medications to seek specialist advice early, warning that poor timing or dangerous use could impact fertility treatment.

Around 1 in 7 UK couples experience difficulty conceiving, and many patients are unaware that these drugs aren’t recommended whilst trying to conceive, or during IVF and pregnancy. While GLP‑1s can support weight loss and overall health, Care Fertility advises caution for anyone pursuing fertility treatment in 2026.

Dr Victoria Sephton, Chief Medical Officer at Care Fertility, comments:
“Weight-loss medications can support people’s general health and weight management, but there is limited evidence of their safety during fertility treatment or pregnancy. Patients who wish to start treatment must be aware of the risks associated with GLP-1s. And if they don’t plan ahead, patients risk unnecessary delays when every month can feel critical. Speaking to your doctor or fertility specialist before starting treatment ensures you make the safest decisions to support your family plans.”

How weight-loss medications can affect fertility

For women, changes in weight and metabolism can affect ovulation and menstrual cycles. Some may notice more regular cycles with weight loss, but sudden changes in body weight or stopping treatment can impact fertility timing.

Dr Sephton comments:
“Stopping or starting GLP‑1 medications can impact hormone balance and cycles, so timing is key. Planning ahead with a specialist helps couples avoid unnecessary delays when trying to conceive.”

Men also need to consider the possible impact of rapid weight changes on hormone balance and sperm health.

“Men often overlook how weight and metabolic health can affect sperm quality,” Dr Sephton adds. “A consultation with a fertility specialist can help ensure both partners are fully prepared for IVF.”

Why timing matters

While weight loss medications are now widely prescribed for obesity and metabolic health, current guidance advises against using these medications whilst undergoing active fertility treatment, and Care Fertility urges stopping well before patients begin their IVF journey.

Care Fertility advises ‘wash-out’ periods of:

• A minimum of one month with tirzepatide (Mounjaro)
• A minimum of two months with semaglutide-based drugs (Wegovy, Ozempic, Rybelsus)

This allows the medication to leave the body prior to treatment for accurate hormone testing, and to reduce unknown risks during conception and early pregnancy.

Dr Sephton comments, “These medications stay in the system much longer than people realise, and they aren’t safe to take during IVF treatment. If you’re considering or currently taking one of these medications, it’s important to speak to a doctor before stopping, to implement sustainable weight loss before or during fertility treatment. However, stopping too late can affect treatment pathways, test results and clinical decision-making if the drugs haven’t left your system, so we recommend that patients plan ahead for the best chances of success.”

Steps to take before starting IVF

Care Fertility stresses that weight loss medications shouldn’t be stopped abruptly or without medical guidance. Instead, Care Fertility encourages patients to:

• Talk to a fertility specialist early about IVF plans and medication use.
• Plan a safe ‘wash-off’ period from GLP‑1 medications before starting treatment, allowing the drugs to clear from the body.
• Focus on overall wellbeing, including balanced nutrition, gentle physical activity, and stress management during and after stopping medication.

Dr Sephton concludes:
“For anyone using weight loss medication and considering their fertility journey in 2026, now is the time to plan. Early intervention facilitates the safest, most effective outcomes for patients. Before starting IVF, simple lifestyle steps like adjusting nutrition, reducing alcohol, or gradually stopping weight-loss medication can make a meaningful difference to treatment outcomes.”

“At Care Fertility, we understand that fertility treatment doesn’t happen in isolation. It sits alongside patients’ daily lives, weight management, lifestyle and long-term health. As weight loss medication prescriptions continue to rise, it’s crucial that patients and the public understand the effect these have on long-term fertility goals and treatment, and receive accurate clinical advice for the best chances of IVF success.”

By planning carefully and seeking expert advice, people using GLP‑1 or other weight-loss medications can approach IVF with confidence and clarity.

ENDS