Retatrutide: The Next Generation Weight Loss Injection Coming Soon to the UK

Table of Contents

Introduction

Weight loss injections like Mounjaro and Wegovy have already transformed the way people manage obesity and type 2 diabetes. But a new treatment is generating worldwide attention: Retatrutide.

Early clinical trials suggest that Retatrutide may be even more effective than existing medications, with patients losing up to 24% of their body weight in under a year.

So what is Retatrutide, when will it be available in the UK, and how does it compare to current treatments? Let’s take a closer look.

What is Retatrutide?

Retatrutide is an investigational weight loss injection developed by Eli Lilly, the same company behind Mounjaro (tirzepatide).

Unlike Wegovy (a GLP-1 receptor agonist) and Mounjaro (a dual GLP-1/GIP agonist), Retatrutide is a triple hormone receptor agonist. It activates:

GLP-1 receptors → reduce appetite and slow digestion
GIP receptors → improve insulin response and satiety
Glucagon receptors → increase energy use and fat burning

This triple action means Retatrutide not only helps people eat less, but may also boost metabolism and target fat loss more directly.

How Does Retatrutide Work for Weight Loss?

Most current treatments work by controlling appetite. Retatrutide goes further by combining appetite suppression with metabolic stimulation.

Think of it as a “next generation” version of Mounjaro:

Suppresses hunger so you naturally eat fewer calories
Improves blood sugar control (important for people with type 2 diabetes or prediabetes)
Boosts fat burning through glucagon pathways

Clinical Trial Results: How Effective is Retatrutide?

In a landmark Phase 2 clinical trial published in The New England Journal of Medicine:

Patients lost an average of 24% of their body weight after 48 weeks on the highest dose.
By comparison, Mounjaro patients typically lose 15–21% of their weight in a similar timeframe.
Many participants also showed improvements in blood sugar, cholesterol, and markers for fatty liver disease.

These results suggest Retatrutide could be one of the most effective weight loss medicines ever developed.

Is Retatrutide Available in the UK?

Not yet. Retatrutide is still in clinical trials and is not currently licensed by the MHRA or approved by NICE.

Timelines are difficult to predict, but most experts believe Retatrutide could become available in the UK from 2026 to 2027 if trials continue successfully.

Until then, patients seeking support can access Mounjaro and Wegovy through trusted pharmacies like Puri Pharmacy.

Possible Side Effects of Retatrutide

Because Retatrutide works on three different hormone pathways, it shares similar side effects to GLP-1 injections:

Nausea
Vomiting
Diarrhoea or constipation
Fatigue
Reduced appetite

In early trials, some patients reported stronger gastrointestinal effects at higher doses. More research is needed to fully understand long-term safety.

Conclusion

Retatrutide could be the most powerful weight loss injection yet, offering a triple-action approach that goes beyond today’s medicines. While it isn’t available in the UK yet, clinical trials are promising and approval could follow within the next few years.

In the meantime, treatments like Mounjaro and Wegovy are already available and can help you start your journey today.