Weight-loss injections UK

Jump to: What’s the difference between liraglutide (Saxenda) and semaglutide (Ozempic/Wegovy)? | Which weight-loss injection is the best? | How much do weight-loss injections cost? | Am I eligible to buy weight-loss injections? | Where can you buy weight-loss injections online? | Why should I buy weight-loss injections via Second Nature?

In the UK, there are only three weight-loss injections that are currently available as of February 2025: liraglutide (Saxenda), semaglutide (Wegovy), and tirzepatide (Mounjaro).

You can either buy these weight-loss injections privately, or you may be able to get them prescribed through the NHS. You must abide by the eligibility requirements in both routes, which we’ll discuss later in this article.

All weight-loss injections have different ‘brand names’ to the name of the drug itself.

Medicines/drugs having different brand names can sometimes be confusing, so one analogy to explain this is with the well-known painkiller medicine, Nurofen; the brand name is Nurofen, but the drug itself is called ibuprofen.

Liraglutide: This drug’s brand name is Saxenda. It is taken as an injection once a day, and the dose is increased over time until it reaches the maximum prescribed dosage.

Semaglutide: The two brand names for this drug are Ozempic and Wegovy. Semaglutide is also taken as an injection but only once per week. Similarly to liraglutide, you increase the dose over time until you reach the maximum prescribed dosage.

Tirzepatide: The brand name for this drug is Mounjaro. It is also taken as an injection but only once per week. Similarly to liraglutide and semaglutide, the dose is increased over time until you reach the maximum prescribed dosage.

Currently, the Wegovy brand form of semaglutide is available for people who are eligible to lose weight in the UK, whereas the Ozempic form is no longer available privately for weight loss.

The most popular weight-loss injection in the UK, as of Feb 2025, is still Mounjaro. At Second Nature, we found that when giving people the choice almost 99% of people choose Mounjaro over Wegovy. As a result, we’ve stopped offering Wegovy to new members and exclusively work with Mounjaro.

People generally choose Mounjaro because it’s had better weight-loss results in the clinical trials, but also because there’s a lot more flexibility with the dosing. If you’re losing weight at a slow and healthy rate (about 0.5% of your body weight per week) then you can stay on the lower doses of Mounjaro for a lot longer.

These lower doses of Mounjaro are less expensive, and will have a lower chance of any side effects.

You can buy Mounjaro as part of our medication-supported programmes if you’re eligible.

What’s the difference between liraglutide (Saxenda) and semaglutide (Ozempic/Wegovy)?

In summary, semaglutide has better reported weight-loss outcomes than liraglutide and also has a lower percentage of reported side effects.

In 2022, a randomised controlled trial was conducted to examine the weight loss achieved by people with obesity. The trial directly compared semaglutide and liraglutide.

The results showed that people taking semaglutide lost more weight (15.8%) than those taking liraglutide (6.4%).

The study also showed that fewer people stopped taking weight loss injections when taking semaglutide (approximately 1 in 8 people) compared to liraglutide (approximately 1 in 4 people).

If you’d like to read more about the differences between liraglutide and semaglutide, we’ve got a much more detailed guide here: Saxenda vs Ozempic

Which weight-loss injection is the best?

If your question to judge what constitutes ‘best’ is: what injection leads to the highest weight loss, based on the published evidence?

Based on this, we would say the best weight-loss injection is tirzepatide (Mounjaro).

Research has shown that tirzepatide supports an average weight loss of around 25% after one year. This study also showed this weight loss was maintained after 20 months on the medication.

Tirzepatide is a weight-loss injection manufactured by the pharmaceutical company Eli Lilly. It’s administered once a week.

As mentioned at the start of the article, the other advantage of Mounjaro is that there’s a lot more flexibility with the dosing. If you’re losing weight at a slow and healthy rate (about 0.5% of your body weight per week) then you can stay on the lower doses of Mounjaro for a lot longer, which will typically be less expensive and less chance of side effects.

How much do weight-loss injections cost?

Weight-loss injections are not cheap. In the UK you could expect to pay around £299 per month for something like semaglutide. At Second Nature, our medication-supported programme starts at £229 for the first 3 months and then moves up to £299 for the higher doses of Mounjaro.

Am I eligible to buy weight-loss injections?

There are strict eligibility criteria to buy weight-loss injections like Mounjaro.

You’ll normally have to take an online quiz to see if you are eligible. In an ideal world, online providers will then double check your answers with your NHS records, and also validate things like your weight when you start your injections, to make sure your actual weight is what you said it was in the quiz.

For example, Second Nature will ask you to take a photo of yourself standing on some weighing scales, alongside checking your NHS Summary Care Record. We’ll also send you a set of digital Bluetooth weighing scales in the post. These are mainly used to track your weight-loss progress over time, but we also use them to validate people’s starting weight to ensure they’re truly eligible for a weight-loss injection.

You can sometimes get a semaglutide or liraglutide prescription through the NHS. The eligibility criteria for the NHS typically are the follows:

• Semaglutide (Ozempic): GPs can prescribe semaglutide to those people living with type 2 diabetes who also have other eligibility criteria. This might include having a BMI of over 30, and where treatment with metformin (the first drug that is typically prescribed to people living with type 2 diabetes) is deemed inappropriate. However, given the current national shortage of semaglutide (Ozempic) in the UK, it’s unknown how many GPs are still giving out new Ozempic prescriptions.
• Liraglutide (Saxenda): GPs typically won’t prescribe liraglutide directly, but instead refer people to what’s called a ‘tier 3 weight management service’. This service is typically for people with a BMI of over 35, and for those people where other methods of weight loss have failed in the past. On a tier 3 weight management service, it’s sometimes possible to be prescribed liraglutide. It’s also possible to be prescribed semaglutide on a tier 3 weight management service.
• Tirzepatide (Mounjaro): Mounjaro isn’t widely available on the NHS as of February 2025. The NHS has announced a 12-year rollout of Mounjaro in the NHS, but this will likely start with people with a high BMI (40/45+) in 2025.

Where can you buy weight-loss injections online?

You can purchase weight-loss injections through online pharmacies and other providers of weight-loss services, like Second Nature.

Other examples of companies providing weight-loss injections would be Boots, Superdrug, Voy, Numan, myBMI, and Juniper.

Why should I buy weight-loss injections via Second Nature?

Second Nature currently provides Mounjaro as part of our Mounjaro weight-loss programme.

Why should you choose Second Nature over other medication providers if you’ve decided to try Mounjaro (assuming you’re eligible)?

For peace of mind.

Second Nature has worked with the NHS for over 6 years providing weight-loss programmes across the UK.

While our Mounjaro weight-loss programme is private and not currently used by the NHS, we’ve built the programmes focusing on scientific evidence, patient safety, and data security.

We hope that our 6+ years of working with the NHS and building a track record of effective weight-loss results will give you peace of mind to give us a try.