weight loss

3 minute read

Tirzepatide and semaglutide: what’s the difference?

By Joe Young | Medically reviewed by Dr Nimlan Shanmugathas

Semaglutide is a tried and tested medication, prescribed for weight loss under the brand name Wegovy. A new treatment, which has also been through rigorous clinical trials, tirzepatide, has demonstrated even greater weight loss effectiveness when combined with a healthy lifestyle.

Let’s see how they compare. 

What is semaglutide?

Focusing on the GLP-1 receptor, semaglutide mimics the gut-produced hormone GLP-1, which signals fullness to the brain, whilst also stimulating insulin secretion, reducing glucagon secretion, and delaying gastric emptying. These targeted actions have shown significant body weight reduction when paired with a healthy lifestyle. Semaglutide is MHRA-approved to treat type 2 diabetes under the brand names Ozempic and Rybelsus, but only Wegovy is approved for weight loss. 

What is tirzepatide?

The principle mechanism of tirzepatide (brand name Mounjaro) is its activation of both the GIP and GLP-1 receptors. It does this by mimicking the incretin hormones GIP and GLP-1 which play a significant role in insulin secretion, satiety and energy balance. By acting on dual receptors, tirzepatide improves blood sugar levels and enhances the feeling of fullness - key factors in achieving weight loss. Like Wegovy, Mounjaro was a type 2 diabetes drug that is now prescribed for obesity. 

Effectiveness of tirzepatide and semaglutide for weight loss

Both tirzepatide and semaglutide have proven effective in clinical trials for promoting weight loss among patients with obesity, showcasing their potential as supporting treatments in weight management. However, it's important to recognise that individuals vary. The speed and success of weight loss with these treatments are affected by multiple factors such as initial weight, commitment to the recommended program, eating patterns, and levels of physical activity. Additionally, specific health conditions and metabolic rates play a critical role in the results. 

Semaglutide for weight loss

A clinical trial of 1961 participants showed that taking semaglutide resulted in a weight reduction of 15% over 68 weeks, compared to less than 3% in the placebo group. 86% of participants achieved a weight loss of 5% or more, validating semaglutide's effectiveness in enhancing weight loss when combined with lifestyle changes. 

Tirzepatide for weight loss

Tirzepatide has shown effectiveness in clinical trials, often leading to greater weight loss over a similar time frame when compared to semaglutide. In a clinical trial of 2539 participants, those using tirzepatide over 72 weeks experienced weight loss, with averages of 15% for the 5 mg dose, 20% for the 10 mg dose, and 21% for the 15 mg dose, compared with a 3% reduction in the placebo group. The trial concluded that the medication supported ‘substantial and sustained weight loss’, as quoted from the study findings, when combined with lifestyle changes.

What’s the difference between tirzepatide and semaglutide?

The primary difference lies in how they work. Semaglutide acts solely as a GLP-1 receptor agonist, whereas tirzepatide combines the action of GLP-1 with GIP receptor agonism. This dual action of tirzepatide potentially offers broader benefits, particularly in weight management and glycemic control, compared to semaglutide's singular focus. 

A consultation with a clinician will determine the best course of action, which may be influenced by side effect tolerances, administration preferences, and specific treatment objectives regarding weight loss and diabetes management. 

The numan take

Semaglutide and tirzepatide are effective treatments for managing obesity. Semaglutide has proven to be both beneficial and safe. Tirzepatide, with its dual-action strategy, offers a new choice for those trying to lose weight when combined with a healthy diet and exercise.