There have been huge advances in weight loss treatments over the last decade with lots of new drugs that can target natural biological pathways involved in hunger and metabolism. One of the new drugs is Retatrutide.

Unlike other Weight Loss drugs, Retatrutide targets three different biological processes. This makes it an interesting Weight Loss drug but currently there is no widely available Retatrutide Weight Loss treatment.

Here is a full overview of this new obesity drug.

What is Retatrutide?

Retatrutide (brand name – LY3437943) is a weekly injectable experimental drug that has been developed to treat obesity and associated metabolic conditions by targeting 3 different hormonal pathways in the body – Glucose dependent insulinotropic polypeptide (GIP), Glucagon Like Peptide-1 (GLP-1) and glucagon.

According to the manufacturer, Eli Lilly, it is a triple hormone receptor agonist drug, meaning it mimics three different hormones in the body.

As of 2026, this is still an experimental drug so has not been approved for use by any agencies.

You must remember this is still an experimental drug so if there are any products selling Retatrutide Weight Loss drugs it should be viewed with suspicion.

How Does Retatrutide Work?

As it targets three different receptors, this drug works in many ways. Each receptor acts on a specific process.

GLP-1 receptor agonists have been looked into as a treatment for obesity and type 2 diabetes. They work to increase feelings of fullness and decrease hunger.

GIP also works to increase feelings of fullness and decrease hunger. However, it is being looked into for its effect on glucose metabolism.

Glucagon causes increased levels of glucose in the blood. The researchers noticed that increasing the glucagon receptor could help to burn fat.

This drug has been designed to target all three – GIP, GLP-1 and glucagon. This means it can help with intake and expenditure.

Trials Results

Trials have shown very promising short and long term results. In a Phase 2 trial from 2023 there were 338 overweight patients that had at least 1 weight related condition. The patients received either a placebo or different doses of the experimental drug for 48 weeks.

The mean % Weight Loss of the placebo was 2.1%. The 1mg dose gave a mean % Weight Loss of 8.7% and the 12mg dose gave a mean % Weight Loss of 24.2%. Not only was there significant Weight Loss, the researchers found that a range of cardiometabolic markers had improved.

They saw less waist circumference, blood pressure, blood sugar, insulin and lipid levels. The next phase of trials had more participants and showed similar results.

According to the manufacturer, patients taking the 12mg dosage lost an average of 28.3% of their body weight over 80 weeks of the TRIUMPH-1 study (announced in May 2026). Remember this is just some of the results from the trials. The FDA will carry out their own investigation.

Benefits of Retatrutide:

The biggest benefit of this drug is how effective it is at reducing body weight. Getting rid of a large amount of excess weight can hugely improve the health of an obese patient.

This can include lowering blood pressure, waist size, blood sugar and cholesterol which can greatly reduce their risk of cardiovascular disease. Researchers are also looking into this drug for treating type 2 diabetes, osteoarthritis and sleep apnea.

Whilst this sounds really appealing, these benefits come from trial data. They are based on the results of a small group of patients. whilst the trials show potential, they do not guarantee everyone who takes this will get the same results.

Side Effects of Retatrutide:

Like most obesity drugs, this can cause some nasty side effects. Patients taking part in the trials most commonly reported feeling nauseous, vomiting and diarrhoea. Other unpleasant gastrointestinal side effects were also reported. These side effects were more common at the start of taking the drug and with higher doses.

The higher the dose, the more the heart rate would increase. In the 2023 Phase 2 trial the highest increases in pulse were seen at week 24. After this the levels began to drop.

As this is an experimental drug the scientists are still working out the correct dose and whether it is safe for mass use.

Is Retatrutide Available for Weight Loss?

This drug is not FDA approved yet. However, Eli Lilly is already producing this drug. At the moment there are only clinical trials taking place in the USA. The manufacturer says it is currently in phase 3 of clinical trials and the results are promising.

However they do advise not to give yourself this drug as you are keen to lose weight. Most of the clinical trials have been on patients with severe obesity.

Patients taking part in the trials had the injectable form. If you purchase the capsule or liquid form from an unverified seller you have no idea what you are putting into your body. You definitely cannot trust the label.

Conclusion

Overall, Retatrutide could prove to be a revolutionary drug for treating obesity. There is a lot of evidence to suggest this drug could help you lose a large amount of weight.

However we would highly recommend speaking to your primary care physician and looking into your options for treating obesity. There is still a lot to learn about this drug including long term consequences and the correct dosage. If you want to take a potentially life changing treatment then it is vital to understand everything about it.