Tirzepatide vs semaglutide: How these work for weight loss

In case you haven't heard, there's a new medication on the block promising to help patients with type 2 diabetes and obesity with significant body weight reduction.

This medication, tirzepatide, is the first of its kind. It works by targeting 2 receptors — the glucose-dependent insulinotropic polypeptide and the glucagon-like peptide 1 receptor, to stimulate body weight reduction in patients.

On the other hand, medications you're probably more familiar with, like semaglutide, only target one of these receptors. So, what are the primary differences between tirzepatide vs semaglutide and how do each of these medications work to help patients with type 2 diabetes mellitus and obesity achieve body weight reductions?

We're putting these 2 medications to the test and reviewing the research to uncover the primary differences between tirzepatide vs semaglutide, the effectiveness and the different processes involved in each medication regarding weight loss and body weight reduction.

What is tirzepatide?

Tirzepatide (otherwise known by its brand name, Mounjaro) is a medication used to help patients with type 2 diabetes with weight loss and lower their blood glucose levels by increasing insulin production and lowering the amount of sugar produced by the liver [1].

Much like other medications helping patients with type 2 diabetes lose weight, tirzepatide slows down the rate of food passing through the body which makes people feel fuller for longer and helps them achieve their weight loss goals [1].

How does tirzepatide work?

Tirzepatide works by targeting the dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) receptor agonists, making it the first weight loss and diabetes care medication that targets 2 receptor agonists.

Both the glucose-dependent insulinotropic polypeptide and glucagon-like peptide 1 receptor agonists are incretin hormones, meaning they are released after food intake and stimulate insulin secretion [2].

Tirzepatide works by mimicking both these receptor agonists, in turn, signalling the pancreas to stop releasing insulin after food intake and alerting the liver to decrease glucose levels [3].

These processes slow down digestion, improve glycemic control and help people feel fuller for longer after eating meals which can all lead to body weight reduction and weight control [3].

What is semaglutide?

Semaglutide is another weight loss and diabetes medication on the market. Much like tirzepatide it is taken as a weekly dose in addition to making lifestyle changes like improving diet and exercise.

Semaglutide is the active ingredient contained in 2 drugs, Ozempic and Wegovy. While Ozempic is licensed for the treatment of diabetes in the UK, Wegovy is used for weight management and has seen great success in assisting body weight reductions in clinical trials and clinical practice, too [4].

Semaglutide for weight loss works to suppress your appetite and slow down stomach emptying, which keeps food in your stomach for longer periods. In turn, this helps you feel fuller for longer, which leads helps patients achieve weight loss results [4].

How does it work?

We mentioned that tirzepatide targets both the GLP 1 and the GIP receptor agonist. But, semaglutide works by mimicking only the GLP 1 receptor agonist, which is produced by your gut after you eat, to signal to the brain that you're full.

Semaglutide for weight loss stimulates the rate of insulin secretion and slows down gastric emptying. This has the potential to spark a significant reduction in body weight, especially when used in combination with healthy lifestyle changes.

Research suggests that the GLP 1 receptor agonists are located in the area of the brain that influences your satisfaction and hunger levels. So, by mimicking the GLP 1 receptor agonist, semaglutide helps you feel fuller for longer and improves the way your body regulates blood sugar levels and fat storage [5].

How effective are tirzepatide and semaglutide for weight loss?

Both tirzepatide and semaglutide are used for weight loss and body weight reduction, producing a significant reduction in body weight in clinical trials among patients with type 2 diabetes and obesity.

So, let's take a closer look at the evidence and research comparing tirzepatide vs semaglutide in their effectiveness at achieving weight loss and body weight reduction results.

Semaglutide for weight loss

Various clinical research suggests that semaglutide is a safe and effective treatment for diabetes and weight loss. A clinical trial evaluating 6 key trials (SUSTAIN 1) involving 7,215 patients was split into 2 treatment groups: 1 with patients taking semaglutide and another in a placebo group with no active drug treatment (or taking another diabetes treatment) [6].

The placebo-controlled study showed that after 1 year of treatment, for those in the semaglutide treatment group, 63% of patients lost 5% or more of their body weight, and 27% of patients lost 10% or more of their body weight, producing more significant weight loss results than the placebo group [6].

In another clinical trial over 2 years, comparing those using 1mg of semaglutide in combination with lifestyle changes (like improving diet and exercise) and those who only implemented lifestyle changes showed an average of 4.9kg of weight loss for those taking semaglutide. On the other hand, those not taking semaglutide only achieved 0.5kg in weight reduction [7].

Tirzepatide for weight loss

Clinical trials of tirzepatide have shown the medication is seeing significant weight loss results in patients with type 2 diabetes mellitus and obesity.

It is important to note that semaglutide for weight loss has more clinical research behind it, as tirzepatide is a newer medication, only gaining FDA approval in the US in 2022 while Ozempic gained FDA approval in 2017 [8][9].

The clinical trial into tirzepatide with over 2500 people who were either obese or overweight was split into 2 treatment groups: those taking tirzepatide and those in the placebo group who didn't take medication.

The clinical trial showed that tirzepatide resulted in a weight reduction of 15-20% of starting body weight for those taking tirzepatide at 72 weeks, while those in the placebo group saw an average weight reduction of 3% [10].

When comparing tirzepatide vs semaglutide for weight loss, tirzepatide resulted in more significant weight loss results than semaglutide. This is likely due to tirzepatide targeting both the glucose-dependent insulinotropic polypeptide receptor and the glucagon-like peptide 1 receptor, while semaglutide only targets the glucagon-like peptide 1 receptor.

What is the difference between semaglutide and tirzepatide?

While tirzepatide and semaglutide are both used to help patients with type 2 diabetes and obesity with weight loss and improve cardiovascular outcomes as a result of their weight-related conditions, there are some primary differences between the medications.

The primary differences between these medications are that they are 2 different classes of medications and target slightly different areas of the brain.

By targeting both the GIP and GLP-1 receptor agonist, tirzepatide is the only medication in its class. Tirzepatide works in different ways than semaglutide by activating both these receptors. On the other hand, Wegovy only targets the GLP-1 receptor agonist but it has been on the market longer than tirzepatide with more research and clinical evidence backing it.

How to access weight loss medications

You can access a number of weight loss medications in the UK, including both Wegovy (semaglutide) and Mounjaro (tirzepatide). In fact, here at Juniper, we offer both medications as part of our Weight Reset Programme. To gain access to these medications, you have to meet certain criteria, including:

• If you have clinical obesity with a body mass index of 30 or more
• If you are significantly overweight with a body mass index of 27 or more and you also have a weight-related medical condition that is either caused or exacerbated by excess body weight (like cardiovascular disease)

It's important to keep in mind that when trying to achieve body reduction and kick your weight loss goals, it's so important to look beyond just medications. That's why Juniper's Weight Reset Programme takes a holistic approach to weight reduction backed by health coaching, lifestyle changes and practical and actionable diet and exercise advice.

We use medication to give your body a biological reset, targeting areas of the brain involved in appetite regulation and lowering your body's set point to help you achieve a significant reduction in weight and reach your weight loss goals.

Plus, our clinical team is involved every step of the way from healthcare professionals, health coaches and dietitians to give you all the tools and support needed to achieve weight loss in the short-term and keep it off too.

Our health coaches guide you with practical tips and tricks to help you implement important lifestyle changes like sticking to a reduced-calorie diet and increasing your physical activity levels. We know losing weight can be challenging, which is why we connect you with a supportive community of people on the journey.