Complete UK Guide — Updated March 2026

Weight Loss Injections UK 2025

Everything you need to know about GLP-1 weight loss injections in the UK — what they are, how they work, which is most effective, and how to get them at the best price.

UK Weight Loss Injections Compared

Most effective

Mounjaro (Tirzepatide)

The newest and most effective weight loss injection available in the UK. Mounjaro targets both GIP and GLP-1 receptors, producing greater weight loss than any other approved treatment.

Type
GIP + GLP-1
Frequency
Once weekly
Avg weight loss
~20%
UK price
£129 – £249/pen
MHRA licensed for weight loss
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NHS available

Wegovy (Semaglutide 2.4mg)

The first GLP-1 injection licensed specifically for weight loss in the UK. Wegovy is now available through some NHS specialist clinics and widely available privately.

Type
GLP-1
Frequency
Once weekly
Avg weight loss
~15%
UK price
£149 – £259/pen
MHRA licensed for weight loss
NHS available
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Off-label

Ozempic (Semaglutide)

Licensed for type 2 diabetes in the UK, Ozempic is sometimes prescribed off-label for weight loss. Wegovy (same drug, higher dose) is the preferred option for weight management.

Type
GLP-1
Frequency
Once weekly
Avg weight loss
~6–14%
UK price
£80 – £150/pen
Off-label for weight loss
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Daily injection

Saxenda (Liraglutide)

An older GLP-1 injection requiring daily administration. Saxenda is still prescribed in the UK but has largely been superseded by once-weekly options like Wegovy and Mounjaro.

Type
GLP-1
Frequency
Once daily
Avg weight loss
~8%
UK price
£180 – £250/month
MHRA licensed for weight loss
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Side-by-Side Comparison

FeatureMounjaroWegovyOzempicSaxenda
MechanismGIP + GLP-1GLP-1GLP-1GLP-1
FrequencyOnce weeklyOnce weeklyOnce weeklyOnce daily
Avg weight loss~20%~15%~6–14%~8%
UK licensed (weight)
NHS available
Price range£129 – £249/pen£149 – £259/pen£80 – £150/pen£180 – £250/month

How Do Weight Loss Injections Work?

Weight loss injections work by mimicking naturally occurring gut hormones called GLP-1 (glucagon-like peptide-1) and, in the case of Mounjaro, also GIP (glucose-dependent insulinotropic polypeptide). These hormones are released after eating and signal to the brain that you are full.

By activating these hormone receptors, GLP-1 medications slow gastric emptying (food stays in your stomach longer), reduce appetite, lower blood sugar levels, and decrease food cravings. The result is a significant reduction in calorie intake, leading to sustained weight loss over weeks and months.

Mounjaro's dual GIP + GLP-1 action is believed to be why it achieves greater weight loss than GLP-1-only medications like Wegovy and Saxenda. The GIP receptor activation appears to enhance the appetite-suppressing and metabolic effects of GLP-1 stimulation.

Weight Loss Injections UK — FAQs

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