Private weight loss injections

What you need to know

If you are thinking about or are using private prescriptions for weight-loss injections (GLP-1 receptor agonists), it’s important to understand how these medications work and why your GP should be informed.

What are the injectable medications for weight loss?

Liraglutide (Saxenda®), semaglutide (Wegovy®) and tirzepatide (Mounjaro®) are medications to help people living with obesity to lose weight, alongside a healthy diet and physical activity. Liraglutide is given as a daily injection, whilst semaglutide and tirzepatide are weekly injections. Liraglutide and semaglutide are used for up to 2 years. Tirzepatide may be used for longer. However, it is common to re-gain weight quickly after stopping these medications.

Can my GP prescribe weight-loss injections?

No. Injectable weight loss drugs are not currently permitted to be prescribed in Primary Care and cannot be taken over even if started privately.

National guidance from the National Institute for Health and Care Excellence (NICE) makes recommendations on eligible groups and does not recommend GPs prescribe liraglutide (Saxenda®) or semaglutide (Wegovy®) for obesity. These medicines are only to be used within specialist weight management services.

Tirzepatide is the most recent medication to be recommended by NICE (December 2024) for some eligible groups for managing obesity. NICE and NHS England have announced it will take 12 years to fully implement the guidance recommendations. This means it will not be available to everyone meeting the criteria in the NICE guidance straight away.

Tirzepatide will be available first in specialist weight management services, starting in spring 2025. From the summer of 2025, it is expected to start being available outside of specialist services, but still alongside a programme of diet and nutrition support and increased physical activity. This support is an essential part of being prescribed these injections.

As part of the phased roll out, tirzepatide will initially be offered to adults with the most significant health problems related to their weight. NHS England will publish further details soon about which patients will be eligible first.

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How do weight-loss Injections work?

Weight-loss injections, help reduce food cravings and manage weight. They work by mimicking a natural hormone that makes you feel fuller for longer, so you eat less.

However, losing weight too quickly can cause you to lose muscle instead of fat. This can weaken your bones and increase the risk of chronic health problems. To avoid this, it’s important to stay active and include exercise—especially strength or resistance training—in your routine. This will help protect your muscles and bones while improving your overall health.

By combining weight-loss injections with regular exercise and a healthy diet, you can lose weight safely and effectively.

Your role in staying safe

To stay safe while using these medications, please be honest and thorough when discussing your medical history with your private prescriber. Make sure they are aware of:

Medications you are already taking
Any existing health conditions
Your complete medical history
Weight-loss injections are intended for people who meet the appropriate criteria. Taking them without meeting these guidelines (e.g., if your BMI is below 30) can put your health at serious risk.

If your provider has has requested that we (your GP practice) provide medical information for them to help them make safe decisions regarding your care, this may safely be given to the provider via the NHS app yourself.

NHS App

If you are unable to do this then we can supply the same information in a computer generated summary for you to forward, although we will make it clear that this does not mean we have made an assessment as to the suitability or safety of the private provider commencing a specific treatment.

The responsibility for prescribing your weight loss treatment sits with the company you have chosen.

Oral Contraceptives (the pill) and Mounjaro (tirzepatide)

Some GLP-1 drugs, such as Mounjaro, may interfere with birth control pills and make it less effective. This happens because Mounjaro can slow down digestion, which may affect how oral contraceptives are absorbed.

If you are taking the pill, it’s important to use an additional barrier method (such as condoms) or consider switching to a non-oral contraceptive method (e.g., implant, coil, or depot injection) during the following times:

The first 4 weeks of starting Mounjaro
4 weeks after any dose increase

Mounjaro is the only GLP-1 drug that includes this specific warning on its label. However, if you are concerned about your contraception while taking any GLP-1 medication, it’s a good idea to discuss this with your prescriber.

Hormone Replacement Therapy (HRT) and Mounjaro and Ozempic/Wegovy

If you are using weight loss medication prescribed privately (such as Ozempic/Wegovy (semaglutide) or Mounjaro (tirzepatide), your private provider should have advised you about how this may affect your HRT.

In particular, if you take oral progesterone (such as micronised progesterone / Utrogestan), the weight loss medication may reduce the womb protection provided during the first 4 weeks of starting or 4 weeks after increasing the dose.

To ensure continued protection:

If you normally take 200mg for 2 weeks of the month, increase to 300mg during those 4 weeks.
If you take 100mg every night, increase to 200mg nightly during that period.
No changes are needed if your progesterone is provided via a patch or hormonal coil.

If you have any questions or are unsure, please contact your private provider, who remains responsible for managing your weight loss treatment for ozempic/wegovy (semaglutide) and mounjaro (tirzepatide).

Informing your GP

If you are prescribed weight-loss injections privately, it is important that your private prescriber notifies your GP.

Here’s why:

Health Records: We will update your medical records to include this information. This is not to seek permission from us, but to ensure we have an accurate record of your medications.
Managing Side Effects: If you become unwell or experience side effects, knowing you are taking weight-loss injections helps us provide the right care.