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, although was previously prescribed off-label for weight loss, Wegovy is used specifically 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 just 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.

Both tirzepatide and semaglutide are considered the gold standard in weight loss treatment, producing comparable results.

In clinical trials, patients on the highest possible dose of Wegovy lost up to 20.7% of their body weight [6], compared to 20.9% with Mounjaro at its highest dose [7] — showing that both can be highly effective when used consistently and with the right support.

With Juniper, Wegovy is delivered as part of a complete programme that includes expert care, coaching, and tracking tools — to help you get the most from your treatment.

Given Wegovy/semaglutide has been available for longer than many newer medications, it is often more more accessible and cost-effective over time compared to Mounjaro/tirzepatide.

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

Juniper's tailored weight loss programme contains clincally backed weight loss medications, including Wegovy and Mounjaro. We take a holistic approach to weight reduction, with clinician-developed plans tailored to your health history, experience with medication and goals — it's not a one-size-fits-all script.

By taking the Juniper quiz, you can check your eligibility and kickstart, or restart, your journey towards a healthier and happier you. If you're unsure where to start, simply begin by answering a few questions in our quiz and our clinicians will support you through this process.