Second Nature logo



Fat-loss Jabs UK

Mike Gibbs
Written by

Mike Gibbs

Medically reviewed by

Fiona Moncrieff

6 min read
Last updated April 2024

Jump to: Which is the best fat-loss jab? | How often do I need to use fat-loss jabs? | How do fat-loss jabs work in your body? | What are the side effects of fat-loss jabs? | How much do fat-loss jabs cost? | How do I buy fat-loss jabs?

In the UK, there are currently two fat-loss jabs available:

  1. Semaglutide: more commonly known as Ozempic and Wegovy
  2. Liraglutide: more commonly known as Saxenda

It’s worth noting that both of these fat-loss jabs are expensive.

Paying privately, generally, you’ll pay at least £299 per month for these jabs, and possibly more.

This is due to the current high demand for these slimming injections both in the UK and also the rest of the world (particularly in the U.S.), which means they are in short supply.

You may ask yourself whether you can get these fat-loss jabs for free on the NHS? It’s possible, but they are typically reserved for quite specific people.

For example, you’d only likely be able to get liraglutide (Saxenda) if you’ve been referred to what’s called a ‘Tier 3 weight management service’, which is a specialist NHS service for people typically with a BMI of over 35 and more complex weight-loss requirements.

For semaglutide, this is typically prescribed through the NHS for people who are living with type 2 diabetes and for whom other medications, such as metformin, are not deemed appropriate.

Currently, Second Nature is the only UK company that provides private fat-loss jabs and is also trusted by the NHS to provide weight-loss services.

Our general recommendation is to try our weight-loss programme first before considering trying fat-loss jabs. We say this for 3 reasons:

  1. Our weight-loss programme is cheaper (£40 per month instead of £299+ per month)
  2. Changing your lifestyle habits is typically more sustainable in the long run
  3. You’re less likely to have any side effects from changing your lifestyle habits

That being said, if you’re determined to try a fat-loss jab like semaglutide, and you also meet the strict eligibility criteria, then we’re going to be biased and suggest that you try Second Nature over other providers (like Boots, Superdrug, Manual, Numan, etc).

Why? for peace of mind

The NHS has used Second Nature for over 6 years, and we ensure we abide by the highest levels of data security and patient safety.

With that, we believe there comes a level of authenticity and peace of mind that other providers cannot match.

Check my eligibility

Which is the best fat-loss jab?

This will depend on what you mean by ‘best’. Two criteria you might use to analyse which is the best fat-loss jab might be:

  1. Which fat-loss jab leads to the highest weight loss?
  2. Which fat-loss jab has the fewest reported side effects?

Based on the available evidence as of 2023, semaglutide is the clear winner for both of these questions.

When semaglutide (Ozempic/Wegovy) and liraglutide (Saxenda) have been directly compared in Randomised Controlled Trials (RCTs) such as this one, then semaglutide has shown better results.

In the RCT linked above:

People using semaglutide had higher weight loss (15.8%) than those using liraglutide (6.4%)

People using semaglutide had fewer reported side effects (approximately 1 in 8 people reported side effects) than those using liraglutide (closer to 1 in 4 people reported side effects)

There’s also the consideration that semaglutide only has to be injected once per week, compared to liraglutide that has to be injected every day.

So with the above in mind, one could make the conclusion that the current best fat-loss jab is semaglutide.

Later in 2023, or perhaps 2024, a new fat-loss jab called tirzepatide is expected to be launched by the drug company, Eli Lilly. From the clinical data released so far, tirzepatide is looking like it might have even better results than semaglutide.

How often do I need to use fat-loss jabs?

As noted above, if you’re using liraglutide (Saxenda) then you’ll need to inject this every day. If you’re using semaglutide then the injection frequency is once a week.

This alone will guide many people’s decisions to which fat-loss jab they choose, because a daily injection is far less desirable than a once-weekly injection.

How do fat-loss jabs work in your body?

Both semaglutide and liraglutide mimic a natural hormone in your body called GLP-1.

To keep things as simple as possible, the GLP-1 hormone has 3 major effects:

  1. It slows the rate of food movement from your stomach to your small intestine
  2. It has some satiety-managing effects on your brain i.e. makes you less hungry
  3. It modulates the release of the insulin and glucagon hormones in your body, ultimately leading to lower blood sugar levels (generally a good thing)

The natural GLP-1 hormone in your body only lasts for a few minutes, whereas the GLP-1 drugs, such as semaglutide, can last for many hours & days. This means they can have the above effects over a more sustained period of time.

If you’d like to read in more detail about how these GLP-1 fat-loss jabs work, then you can check out our weight-loss jabs guide or our longer guide on GLP-1 receptor agonists.

What are the side effects of fat-loss jabs?

The most common side effects of semaglutide are nausea, constipation, vomiting, and other symptoms affecting the gastrointestinal (GI) tract, like diarrhoea.

These symptoms most commonly occur around the time of the injection and as you increase the dosage of the medication over time, and then symptoms typically ease after adapting to the medication.

As you might have linked from the section above about how these GLP-1 drugs work, it’s thought that these side effects are linked to your body adapting to the new and slower rate of food moving through your digestive system.

It’s worth noting that everyone responds differently to these medications; some people won’t experience any side effects, whilst others will.

We have a longer guide on semaglutide side effects if you’re interested to read more.

How much do fat-loss jabs cost?

Fat-loss jabs are not cheap. In 2023 you can expect to pay at least £299 per month, but most likely more. This is primarily because of a global shortage of these fat-loss jabs due to overwhelming demand.

It’s expected that the cost of fat-loss jabs will stabilise in 2024, but if and when this happens will come down to the decisions of the pharmaceutical drug manufacturers.

How do I buy fat-loss jabs?

As mentioned at the start of this article, our general recommendation would be to try our weight-loss programme first before considering taking any fat-loss jabs.

Our original weight-loss programme is less expensive, more sustainable, and you generally don’t have any side effects when just making lifestyle and habit changes.

However, if you’ve decided that you would like to try a fat-loss jab, and you also meet the eligibility criteria, then the first step is to take our online health quiz.

You’ll then be evaluated by Second Nature and one of our pharmacy team to see if you’re eligible for our medication-supported programme.

Wegovy information

Product name Wegovy
Active ingredient Semaglutide
Manufacturer Novo Nordisk
Price £229
What’s included?
    • Access to a registered nutritionist or dietitian five days a week via our award-winning app
    • Weighing scales and our hardback recipe book
    • Peace of mind that we’re the only Wegovy provider who’s also trusted by the NHS to deliver weight-loss services
Second Nature Trustpilot rating 4.8/5
Second Nature Trustpilot reviews 6,888 (as of January 2024)
Availability In stock
Description Once weekly weight-loss injection
Administration Subcutaneous injection (multiple sites like the arm, stomach, or leg)
Presentation Injection pen
Available dosage 0.25 mg, 0.5 mg, 1 mg, 1.7 mg, 2.4 mg
Drug class GLP-1 receptor agonist
When pregnant/breastfeeding Not permitted


Check my eligibility

You might also like

Make losing weight feel Second Nature

The first step on your Second Nature journey is to take our health quiz.

Hand holding phone

Write a response

As seen on

The GuardianThe TimesChannel 4The Sunday Telegraph
Evening Standard