Retatrutide: The weight loss drug everyone's talking about

The world of weight loss has been changing rapidly since new medications came onto the scene. A number of drugs are now approved for weight management, but researchers are not done yet.

As they continue to explore new active ingredients and their potential to support weight loss, some people have been jumping ahead to gain access before clinical trials are finished.

Which is where retatrutide comes in. This emerging medicine is showing strong potential to become the next generation of weight loss injections, but it’s not yet ready for launch.

We’re here to help you separate fact from fiction by exploring what retatrutide is, how it works and why the best option is still approved medications from a trusted provider. 

What is retatrutide?

Retatrutide is a new medication that researchers believe has the potential to help promote weight loss and treat type 2 diabetes [1].

Pharmaceutical company Eli Lilly is currently developing the drug, though it is not approved for use yet. This is the same manufacturer that makes approved weight loss medication, Mounjaro [6][8].

While researchers hope that someday retatrutide might become the next generation of anti-obesity medication, for now it is best described as an emerging medicine. 

How does retatrutide work? 

Retatrutide is one of the first triple agonist medicines. This means that it activates all 3 of the hormonal pathways that have been linked to weight loss, including [1]:

• Glucagon-Like Peptide 1 (GLP-1)
• Glucose-Dependent Insulinotropic Polypeptide (GIP)
• Glucagon

Each of these hormones has a role to play in your body, such as suppressing appetite, slowing digestion, increasing fat metabolism and regulating blood sugars.

When combined, these hormones can help you to lose weight and control blood sugar. A key difference between retatrutide and other weight loss medications, like Wegovy or Mounjaro, is that it activates more hormones, including the ones related to fat burning [8].

Retatrutide vs tirzepatide: how do they compare?

Before we talk about how these medications compare directly, we wanted to give you a quick refresher on tirzepatide.

Tirzepatide is the active ingredient in the approved weight loss medication, Mounjaro. The Medicines and Healthcare products Regulatory Agency (MHRA) approved Mounjaro for use in the UK in 2023, after multiple studies found it was a safe and effective medicine for the majority of people [2].

The main difference between retatrutide and tirzepatide is how many hormonal pathways they activate [4].

Tirzepatide is what’s known as a dual agonist. That means it works on 2 pathways, namely, GLP-1 and GIP [1]. Retatrutide is a triple agonist. That means it works on 3 pathways: GLP-1, GIP and glucagon.

A review of multiple studies which directly compared the 2 drugs found that retatrutide had a slightly stronger effect on weight loss [4].

While that might seem like retatrutide is a clear winner, it’s not the whole picture. People on retatrutide also experienced more side effects than those taking tirzepatide, which could mean they’re more likely to stop using the medication.

Another important finding was that both medications helped achieve greater weight loss compared to a placebo. In other words, people lost more weight on either medication than they did with none.

Is retatrutide available in the UK?

To keep it short and simple: retatrutide is still undergoing clinical trials, so it's not approved yet in the UK [6]. But that doesn’t mean it’s never going to be available.

Before a medication is approved for use, it usually goes through a long and careful research process. The gold standard is Phase 3 clinical trials, which assess how safe and effective a medication is in a general population, especially for long-term use [1].

Since retatrutide showed promising results during Phase 1 and 2 trials, researchers are now moving on to Phase 3. There are at least 4 separate studies in progress which need to be completed before the drug can be properly reviewed by regulatory bodies.

While we do have research that shows retatrutide is effective for weight loss, we still need clinical studies to give us the long-term safety data [3].

Some key areas of interest are how this new medication might affect your heart or kidneys, and whether it burns muscle mass alongside fat.

So, while the research community is excited about the potential benefits of retatrutide, it could be a while before this medication moves out of clinical trials and into the general population.

What are the side effects of retatrutide?

Like most medications, retatrutide comes with a few potential side effects. Commonly reported ones include [1][5]:

• Nausea
• Diarrhoea
• Vomiting
• Constipation or difficult bowel movements
• Losing strength or feeling weaker
• Heartburn
• Feeling thirsty

Most of these side effects seem to be linked to the dosage schedule, with a higher dose making side effects more likely or severe. That means if a dose is gradually increased, then it might help to minimise side effects.

But, there is one side effect which is being investigated further – losing strength or muscle mass. 

Some participants in retatrutide trials have been losing weight too fast or from the wrong places [1][8]. Rather than targeting mostly fat mass, the drug might be affecting muscle and bone mass as well. 

This could be an issue for your future health as it impacts your strength and mobility. It could also lead to weaker bones or potential diseases such as gallstones or pancreatitis.

These side effects are a key reason that more research is needed before retatrutide is given the green light as an approved medication.

How to get retatrutide safely

We’re not going to pretend that people are not accessing retatrutide. But we also know that no one who has used it so far is doing so safely. 

That’s because it’s not an approved medication, so any access right now is through the black market [7][8].

Here’s the thing: it’s not totally your fault. You might hear about something called ‘triple g’ on social media or from someone at the gym. They tell you it’s a cheaper, better option compared to current weight loss methods.

When you click through to buy, the website looks legitimate with plenty of reviews and a high trust score. But, they’re not giving you the whole story.

A lot of these websites are from overseas companies that are selling active ingredients that are meant for clinical research. They’re not allowed to sell them, but they get around this by disguising shipments as skincare products or labelling them ‘research only’.

So while it is possible to get retatrutide, there are big risks to doing so before it’s approved. You won’t know the right dosage, you may not be given the correct ingredients, and you might even have to mix up the medicine by yourself.

That’s a completely different experience to using a reputable provider like Juniper, who offer approved medications in safe and easy-to-use formats, prescribed by accredited UK clinicians.

We can’t help any of our patients to access retatrutide yet, simply because it’s not approved. But we do provide leading medications like Wegovy and Mounjaro, which are approved.

What are the alternatives to retatrutide? 

We know that weight loss is an important goal for a lot of people. In fact, helping you achieve it is one of our main goals too.

Rather than recommend a risky, unapproved medication, we wanted to talk about the safe, approved alternatives that are available to you right now. 

Diet and exercise 

Let’s start with the crème de la crème of losing weight and keeping it off. Any person who wants to improve their body composition should take a good look at their diet and exercise [9].

A healthy weight loss diet usually involves eating fewer calories and choosing more whole foods. While lower calories are the goal, be careful of fad diets and trends – like the cookie diet or the boiled egg diet – as these can have unexpected consequences for your health.

When it comes to exercise, a good starting point is at least 30-minutes per day, for 5 days of the week. This can be moderate intensity exercise, such as walking, swimming, cycling or dancing.

There’s also balance and strength training that you can put into place a few times each week.

While diet and exercise remain the primary weight loss plan for most people, the truth is – they can be hard to stick with for the long-term [1]. Which is why health professionals have opened up the doors to other options, like medication.

Approved weight loss medications

There are 4 medications that are currently approved to help with weight management in the UK [9]: 

• Orlistat
• Liraglutide
• Semaglutide
• Tirzepatide 

At Juniper, we help people access semaglutide (as Wegovy) and tirzepatide (as Mounjaro). All of these medications should be prescribed by a qualified health professional, like a doctor or pharmacist.

You also still need to focus on reducing calories in your diet and increasing physical activity while taking weight loss medication.

Keeping up with diet, exercise and medication can be complicated and require support from a range of health providers. Which is why programmes like ours exist; to help you simplify and stick with your weight loss plan.

A holistic weight loss programme 

The Juniper Programme combines weight loss medication with dietitian-led health coaching and tracking, so you can lose weight and reach your goals for good. 

Kickstart your weight loss journey with Wegovy or Mounjaro, two groundbreaking weight loss medications that mimic the GLP-1 and GIP hormones, respectively, to help control cravings, delay stomach emptying, and keep you feeling fuller for longer. These clinically backed treatments help members experience up to 20% body weight loss.

Plus, we have a team of expert dietitians and health coaches you can consult with to help you work through any challenges you're experiencing during your weight management journey. This approach sets you up for sustained weight loss, rather than a quick-fix solution.

This means you can continue to enjoy the things you love in moderation without ever feeling deprived.

Ready to see if Juniper is right for you? You can check your eligibility here.

Weight loss surgery

We like to be thorough and transparent, so we thought it was worth mentioning one more medically-approved weight loss option – bariatric surgery [9]. 

This is typically used as a last resort for people who have tried every other method with little success. There are strict guidelines on who is eligible for weight loss surgery, so it’s not the most common or preferred option.

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