The NHS has issued an important notice to patients taking Mounjaro weight loss injections alongside the contraceptive pill or HRT, warning the medication can affect their effectiveness
The NHS have issued a warning to those taking Mounjaro(Image: )
As January arrives, many individuals will be establishing fresh health and fitness goals for the New Year, including aspirations to lose weight. Consistent physical activity, gym attendance, and a well-balanced, wholesome diet are essential components that improve overall wellbeing and can help in losing those unwanted pounds.
Nevertheless, for some people, these approaches may prove insufficient.
Particular medications that can promote weight loss might be suitable for certain individuals, though they are typically intended for people with type 2 diabetes and potentially those who have found it difficult to shed weight through lifestyle changes alone. These aren’t exclusively for those who “can’t” lose weight on their own, but instead act as a useful aid when alternative methods haven’t delivered satisfactory outcomes.
Read more: What Coventry looked like in 1986 as fascinating faces and photos unearthed
Read more: Four new must-see destinations you can fly to from Birmingham Airport in 2026
GLP-1 agonists are medications such as tirzepatide and semaglutide, frequently known by brand names like Mounjaro, Ozempic, or Wegovy. They are prescribed for individuals with type 2 diabetes or to support chronic weight management in specific adults.
These drugs work by reducing the speed at which food leaves the stomach, replicating gut hormones to control blood sugar levels and curb appetite, according to the Mirror. Recent estimates from late 2025 indicate that hundreds of thousands of people across the UK – potentially exceeding half a million – are using Mounjaro (tirzepatide) for weight management, predominantly without medical supervision, reports Lancs Live.
Some figures suggest the combined total of Mounjaro and Wegovy users could reach between 1.5 and 2.5 million. Despite this, stringent eligibility criteria mean fewer than 220,000 individuals are anticipated to access it via the NHS within the next three years.
An important NHS warning has been issued for those who have been prescribed such injections by their GP. The alert particularly concerns patients simultaneously taking other medications, including the contraceptive pill and Hormone Replacement Therapy (HRT).
The NHS website has published an ‘important notice’ aimed at patients using these injections whilst also taking either the contraceptive pill or HRT. The health service warns that certain injections may reduce the effectiveness of both the pill and HRT.
The statement explains: “Many patients are now using weight loss medications like Tirzepatide (Mounjaro) or Semaglutide (Ozempic, Wegovy, Rybelsus) – either for diabetes or privately for weight loss. These medications work partly by slowing down how your stomach empties, which can affect how well other medicines (like the contraceptive pill or HRT tablets) are absorbed by your body.”
For those taking the contraceptive pill: Tirzepatide (Mounjaro) may reduce the efficacy of any oral contraceptive, including the Progesterone-Only Pill. The NHS recommends that you:.
The guidance states: “Use extra protection (like condoms) if you have vomiting or diarrhoea and follow the missed pill rules (see the patient information leaflet which comes with your pill) if you vomit within three hours of taking the pill or have diarrhoea for more than 24 hours.”
With regards to Semaglutide and similar medications, the NHS confirms “these do not appear to reduce the effectiveness of the pill”. Nevertheless, side effects including vomiting or diarrhoea may still affect the pill’s absorption.
“So, use extra protection (like condoms) if you have vomiting or diarrhoea and follow the missed pill rules (see the patient information leaflet which comes with your pill) if you vomit within three hours of taking the pill or have diarrhoea for more than 24 hours,” the NHS advises. “Please see further information here: Patient Information GLP 1 Agonists And Contraception.”
The NHS further clarifies that GLP-1 agonists do not affect non-oral contraceptive methods. Therefore, it remains safe to use alternatives such as the coil (IUD), implant, or injection without requiring additional precautions whilst taking a GLP-1 agonist.
Should you wish to switch your contraception method, it’s advisable to consult with your GP. The health service adds: “GLP-1 agonists should not be used if you are pregnant. It is crucial to use effective contraception when taking these medicines. If you become pregnant while on these medications, you should speak to your doctor immediately. You should also stop taking GLP-1 agonists several weeks before attempting to conceive.”
For those receiving Hormone Replacement Therapy (HRT), there are worries that particular medications – including Tirzepatide (Mounjaro) and Semaglutide – could reduce the absorption of these tablets. The NHS cautions: “This could lead to irregular bleeding and may affect the protection of your womb lining (potentially leading to an increased risk of endometrial cancer).
“Contact the surgery to discuss your HRT or contraception options while using weight loss medication.”
Get daily headlines and breaking news emailed to you – it’s FREE
