An honest comparison of two widely studied GLP-1 medications for weight loss, based on published clinical trial data.
Both medications are GLP-1 receptor agonists used for weight management and type 2 diabetes. Here is how they compare on the key factors.
| Tirzepatide (Mounjaro) | Semaglutide (Ozempic/Wegovy) | |
|---|---|---|
| Mechanism | Dual GIP + GLP-1 receptor agonist | GLP-1 receptor agonist only |
| Average weight loss (placebo-controlled) | Up to 22.5% of body weight SURMOUNT-1, NEJM 2022 | Up to 14.9% of body weight STEP 1, NEJM 2021 |
| Head-to-head (same trial) | −20.2% at 72 weeks SURMOUNT-5, NEJM 2025 | −13.7% at 72 weeks SURMOUNT-5, NEJM 2025 |
| Administration | Weekly subcutaneous injection | Weekly subcutaneous injection |
| Starting dose | 2.5 mg | 0.25 mg |
| Dose range | 2.5 mg – 15 mg | 0.25 mg – 2.4 mg |
| Manufacturer | Eli Lilly | Novo Nordisk |
| Common side effects | Nausea, diarrhoea, reduced appetite | Nausea, diarrhoea, reduced appetite |
| Approved for | Type 2 diabetes (Mounjaro); weight management in some regions | Type 2 diabetes (Ozempic); weight management (Wegovy) |
Semaglutide is an effective medication. Our decision to focus on Tirzepatide is a product decision based on evidence, focus, and quality control.
Tirzepatide activates two receptors: GIP and GLP-1. GLP-1 slows gastric emptying and reduces appetite. GIP improves insulin sensitivity and may enhance fat metabolism. Together, these two pathways produce a stronger combined effect on weight than GLP-1 alone.
The SURMOUNT-5 trial (NEJM 2025) compared the two medications directly in the same study. At 72 weeks, participants on tirzepatide lost 20.2% of body weight on average. Those on semaglutide 2.4mg lost 13.7%. Tirzepatide also led in the placebo-controlled SURMOUNT-1 trial (up to 22.5% over 72 weeks) compared to STEP 1 for semaglutide (up to 14.9%). Individual results vary, but every major trial favours tirzepatide on average.
By focusing on a single medication, we can build tighter review protocols, a single dose ladder, and more consistent onboarding and support. One product means every process is optimised for that product specifically.
Three large trials, peer-reviewed and published in the New England Journal of Medicine. Two placebo-controlled, one head-to-head.
The first randomised head-to-head trial between tirzepatide and semaglutide 2.4mg. At 72 weeks, tirzepatide produced 47% greater weight loss on average than semaglutide. Same trial. Same protocol. Same patient population.
Aronne et al., New England Journal of Medicine, 2025Participants on the highest dose (15 mg) lost up to 22.5% of body weight over 72 weeks. The trial enrolled 2,539 adults with obesity or overweight with at least one weight-related condition.
Jastreboff et al., New England Journal of Medicine, 2022Participants on the 2.4 mg dose lost up to 14.9% of body weight over 68 weeks. The trial enrolled 1,961 adults with obesity or overweight with at least one weight-related comorbidity.
Wilding et al., New England Journal of Medicine, 2021Published trial data shows higher average weight loss with Tirzepatide, but individual results vary significantly. What is "better" depends on your body, your tolerance, and your goals. Both are effective, evidence-based GLP-1 medications. We present the data and let you decide.
Yes, with care team review. If you have previous GLP-1 experience, this is assessed during your intake. Your starting dose and titration schedule may be adjusted based on your prior treatment history, tolerance, and response.
Focus. One medication, one dose ladder, tighter review, and better support. By concentrating on Tirzepatide, every part of our process — from assessment to onboarding to dose progression — is built specifically for this treatment. That focus translates to higher quality at every step.
The side-effect profiles are similar. Nausea is common with both medications, especially during dose escalation, and usually settles within the first few weeks. Tirzepatide users report similar gastrointestinal side effects to semaglutide users. Both medications carry a boxed warning regarding thyroid C-cell tumours observed in animal studies.
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