A Beginner's Guide To Retatrutide (Triple G)

Retatrutide, also known as Triple G, is generating attention as a potential new treatment for weight loss and related health conditions. Developed by Eli Lilly, this experimental drug targets multiple pathways in the body, setting it apart from other medications currently available. Although not yet approved in the UK, it is being discussed for its promising clinical trial results and potential benefits.

In this guide, we explore what retatrutide is, how it works, what it's used for, how it compares with other treatments and what to expect in terms of availability, safety and cost.

Key Takeaways

Here are the five biggest takeaways from this article about Retatrutide (Triple G):

• Retatrutide is a potential weight loss medication that targets three hormonal pathways involved in appetite and metabolism.

• Early clinical trials have shown significant weight loss in participants, with some losing over 30% of their body weight.

• It is administered via a weekly subcutaneous injection using a pen.

• Retatrutide is not yet available in the UK, with phase III trial results expected in 2026.

• Existing medications like Mounjaro and Wegovy remain safe and effective options, available through UK Meds.

What is retatrutide?

Retatrutide, often referred to as Triple G, is a new medication developed by Eli Lilly. It belongs to a class of drugs known as GLP-1 receptor agonists, but it goes further by also targeting GIP (glucose-dependent insulinotropic polypeptide) and glucagon receptors. This triple-action mechanism is designed to help regulate appetite, improve glucose control and promote fat breakdown.

Unlike older medications that focus on a single pathway, retatrutide combines multiple effects to provide a more comprehensive approach to weight loss and management. This may make it more effective in supporting long-term weight loss and metabolic health.

What is retatrutide used for?

Retatrutide is being primarily studied as a treatment for obesity and weight-related conditions. This includes people living with type 2 diabetes, high blood pressure, or high cholesterol. In clinical trials, it has also shown potential benefits for reducing the risk or progression of non-alcoholic fatty liver disease (NAFLD), a common condition linked to obesity and insulin resistance.

How is it administered?

Retatrutide is designed to be taken as a weekly injection using a pen similar to those used for other GLP-1 medications. It is administered subcutaneously, meaning just under the skin, typically into the thigh, upper arm or stomach.

Treatment is expected to begin with a lower dose that gradually increases over time. This approach helps the body adjust to the medication and reduces the risk of side effects such as nausea or digestive discomfort. If approved, patients would likely follow a structured dose escalation schedule under the guidance of a healthcare professional.

Retatrutide Side Effects

As with any medication, retatrutide has the potential to cause side effects. So far, the most commonly reported effects are similar to those seen with other GLP-1-based drugs. These include:

• Nausea

• Diarrhoea

• Vomiting

• Constipation

• Abdominal discomfort

Most side effects appear to be mild to moderate and often improve as the body adjusts to treatment. However, more serious reactions are possible, and people who experience persistent or severe symptoms may need to stop treatment and consider alternatives.

Ongoing clinical trials will provide more detailed information about long-term safety, tolerability and how different patient groups respond to the medication.

When will retatrutide be available in the UK?

Although early trial results are encouraging, retatrutide is not yet approved for use in the UK or elsewhere. It is still undergoing clinical evaluation, with the current phase III trials expected to be completed in May 2026. These large-scale studies will help confirm the drug’s safety and effectiveness across a broader population.

After the trial results are released, authorities such as the Medicines and Healthcare products Regulatory Agency (MHRA) and the National Institute for Health and Care Excellence (NICE) will assess whether to approve the treatment for UK use.

How much will retatrutide cost?

At this stage, there is no confirmed price for retatrutide in the UK. However, it is likely to be priced similarly to other advanced weight loss medications such as Wegovy (semaglutide) and Mounjaro (tirzepatide). The final price will depend on factors such as dosage, strength and manufacturer pricing.

Who can use retatrutide?

If approved, retatrutide is expected to be suitable for adults living with obesity or who are overweight with at least one weight-related health condition. This could include high blood pressure, type 2 diabetes or high cholesterol.

It is likely to be prescribed alongside lifestyle changes such as dietary improvements and increased physical activity. As with other medications in this class, not everyone will be eligible. A full assessment will be required to determine suitability based on individual health status and medical history.

Retatrutide vs. Other Weight Loss Medications

Retatrutide is being closely compared with other well-established weight loss medications like Mounjaro and Wegovy. Both of these are currently available in the UK and have helped many people achieve significant results.

Mounjaro works by activating GLP-1 and GIP receptors, while Wegovy only targets the GLP-1 pathway. Retatrutide, by activating GLP-1, GIP and glucagon receptors, may offer an even more effective solution by promoting appetite reduction, fat breakdown and improved blood sugar control.

Early data suggests that retatrutide could surpass both Mounjaro and Wegovy in terms of weight loss results, though longer-term data is still needed to confirm this.

Retatrutide Clinical Trials

Retatrutide is currently in phase III clinical trials, which are the final step before potential approval. These trials aim to confirm the drug’s effectiveness and safety in large groups of people.

In earlier studies, patients taking the highest dose of retatrutide lost an average of 24.2% of their body weight over 48 weeks. More than one in four participants lost over 30% of their initial weight. These results are among the highest reported in weight loss drug trials so far.

The phase III trial is scheduled to conclude in May 2026, with full results expected later that year. These findings will be critical in determining whether retatrutide is approved for use in the UK [1] [2] [3] [4].

Your Weight Loss Journey

Everyone’s weight loss journey is different. What works well for one person may not be the right choice for another. While retatrutide is not yet available, there are already safe and effective options that can be prescribed today, including Mounjaro and Wegovy.

At UK Meds, all prescription requests are subject to an online clinical consultation. This ensures the treatment is only supplied if it is considered safe and appropriate by a qualified independent prescriber.

Making steady, sustainable progress is key. Weight loss is most successful when combined with good nutrition, regular movement and the right professional support.

Final Thoughts

Retatrutide could be a major development in the world of weight loss treatments, offering a triple-action approach that may outperform existing medicines. Its ability to target multiple hormones involved in hunger and metabolism makes it a promising potential option.

However, it is still being studied and will not be available until the final clinical trial results are complete. In the meantime, trusted medications like Mounjaro and Wegovy remain ideal for people looking to manage their weight. Always seek professional guidance before starting any new treatment.

Sources

[1] Clinical trials - NHS

[2] Triple–Hormone-Receptor Agonist Retatrutide for Obesity — A Phase 2 Trial | New England Journal of Medicine

[3] A Study of Retatrutide (LY3437943) in Participants With Obesity and Cardiovascular Disease (TRIUMPH-3) - Lilly

[4] Triple-Hormone-Receptor Agonist Retatrutide for Obesity - A Phase 2 Trial - PubMed