Wegovy vs Mounjaro: Choosing the Right GLP-1 for Weight Loss and Wellness

Written by Shereen Amin MRPharmS, UK-registered Pharmacist Prescriber and Medical Writer (GPhC 2073003)

What Are GLP-1 Treatments and How Do They Work?

GLP-1 treatments are a group of medications originally developed to manage Type 2 diabetes. However, many people are now using them to support healthy eating habits and lose weight. Popular medicines in this category include Wegovy and Mounjaro.

GLP-1 receptor agonists mimic a natural hormone in the body called GLP-1. This hormone helps control appetite, slow stomach emptying and regulate blood sugar levels. The result? You feel full sooner and for longer, have fewer cravings, and can stick to a healthier eating plan more easily.

Additional benefits of GLP-1 treatments include:

Reducing cholesterol levels¹
Improving fatty liver disease²
Cutting down the risk of heart attack and stroke³

Mounjaro also works on another hormone called GIP, which also helps manage blood sugar and appetite. Because it targets both GLP-1 and GIP, some people find it offers stronger results for weight loss and metabolic health.

Wegovy vs Mounjaro: Key Differences and Which Is More Effective

Feature	Wegovy	Mounjaro
What it is	A weekly GLP-1 injection medicine that helps you feel full and lose weight.	A weekly GLP-1 injection medicine that helps you feel full and lose weight, with an extra hormone that may boost results.
How it works	Slows stomach emptying and reduces appetite.	Slows stomach emptying, reduces appetite, and adds extra weight-loss support through dual GLP-1 and GIP action.
How often do you take it	Once a week.	Once a week.
Dose steps	Start small and increase, at minimum four-weekly intervals, until reaching the full dose (0.25 → 2.4 mg).	Start small and increase, at minimum four-weekly intervals, until reaching the full dose (2.5 → 15 mg).
Average weight loss in studies	About 14% of body weight over 72 weeks.⁴	About 20% of body weight on average over 72 weeks.⁴
Common side effects	Nausea, vomiting, diarrhoea, constipation.⁵	Nausea, vomiting, diarrhoea, constipation.⁶
Extra info	Has been studied for longer, with a well-known safety profile.	Newer medicine, which may help achieve bigger weight-loss goals.

Table 1: Comparison of Wegovy vs Mounjaro for weight management, including mechanisms, dosing, and typical weight loss outcomes.

How Much Weight Can You Lose on Wegovy and Mounjaro?

Clinical studies comparing Wegovy and Mounjaro found that people on Mounjaro lost more weight at each stage of treatment than those taking Wegovy:

Time point	Average weight change with Mounjaro	Average weight change with Wegovy
3 months	−5.9%	−3.6%
6 months	−10.1%	−5.8%
12 months	−15.3%	−8.3%

Table 2: Comparison of average percentage weight loss at 3, 6 and 12 months for Mounjaro and Wegovy, showing greater reductions with Mounjaro.⁷

Figure 1: Weight loss rates are slightly lower in patients with Type 2 diabetes and higher in those without diabetes, as illustrated in the above graphs.⁷

Stopping GLP-1 weight loss medications can lead to some weight regain, even when healthy habits continue. The more weight lost during treatment, the more likely some will be regained.⁸ These treatments work best when used as part of a long-term plan to maintain progress and support overall well-being. At Medy, we guide you through each step with practical support and care.

GLP-1 Side Effects and Safety: What to Expect with Wegovy and Mounjaro

GLP-1 treatments like Wegovy and Mounjaro have strong evidence behind them, but they can cause side effects. Understanding what’s common, what’s rare, and what to watch for helps you stay prepared and reassured during treatment.

Common side effects

The most frequently reported symptoms for both Wegovy⁵ and Mounjaro⁶ include:

Nausea and vomiting
Diarrhoea or constipation
Headache
Fatigue
Indigestion
Injection site reactions

These are generally mild or moderate and most often appear when doses increase. They usually settle down after a few weeks as the body adjusts.

Many patients find that smaller meals, less fatty food, and good hydration make a big difference. Gradually increasing the treatment dose can also reduce side effects and make the process smoother.

Serious and rare side effects

These are uncommon but should be taken seriously:

Pancreatitis: inflammation of the pancreas that can cause severe abdominal pain, nausea and fever.
Gallbladder disease: including gallstones and cholecystitis (gallbladder inflammation).
Hypersensitivity reactions: anaphylaxis is a rare side effect for both Wegovy and Mounjaro, affecting less than one in 1,000 patients.

Who should be cautious

The following conditions do not necessarily rule out treatment as an option, but they do need careful consideration. You should tell our clinical team if you have:

History of pancreatitis or gallbladder disease
Severe gastrointestinal disorders
Thyroid cancer or family history of medullary thyroid carcinoma
Reduced kidney function

Choosing the Right GLP-1: Is Wegovy or Mounjaro Better for You?

When deciding between GLP-1 medications like Wegovy and Mounjaro, there is no one-size-fits-all answer. The right choice depends on a range of personal factors, and here at Medy, we offer our expertise and support to help you make the right choice and achieve your goals.

Factors to consider:

Lifestyle – both medications are weekly injections, but side effects and tolerability can vary. Both work best alongside healthier diet choices and increased physical activity.
Health and weight goals – Mounjaro has demonstrated a greater average weight loss than Wegovy in clinical trials,⁴ possibly due to its dual GLP-1 and GIP action.
Cost – pricing may vary, but Medy aims to offer competitive rates and full clinical support.
Switching between medications – moving from Wegovy to Mounjaro (or vice versa) is possible, and sometimes necessary due to side effects, cost or efficacy. Doses are not directly equivalent, but our Medy Clinical Team will be happy to advise on the most suitable option for you.

Real Patient Experiences: Life on Wegovy and Mounjaro

Thousands of people have regained confidence and control over their health using GLP-1 injections. Clinical data tells one side of the story, but hearing real patient experiences can give a clearer idea of what it’s truly like.

Wegovy: steady, consistent progress and appetite control

Patients often describe:

Strong appetite suppression, less “food noise” and reduced cravings.
Moderate weight losses within the first few months.
A boost in confidence and improved sense of well-being.
Some mild side effects, such as nausea or fatigue in the early stages.

"
“I’ve lost 2.5 stone in 6 months. It’s not been easy, but Wegovy helped me stay on track and feel less hungry.” Wegovy user

Mounjaro: faster results with stronger effects

Many people using Mounjaro report quicker results in the first three months. Appetite suppression, reduced “food noise”, and general health benefits are noted, much like with Wegovy. Side effects are very similar.

"
“I am so proud to say that 6 months in I have lost 4 and a half stones… More importantly I just feel so much healthier in every way… It’s taken away that food noise but what does that mean?? For me it means I can focus on healthy meal planning without that insatiable craving for sugar.” Mounjaro user

Every patient’s experience is unique. Finding the right fit for your body and lifestyle matters most. With the guidance of an experienced healthcare team, you can reach your goals safely and confidently.

Ready to take the next step? Book a consultation with the Medy Clinical Team to discuss Wegovy and Mounjaro, find the right treatment for you, and track your progress with confidence.

References

Berberich AJ, Hegele RA. Lipid effects of glucagon-like peptide 1 receptor analogs. Curr Opin Lipidol. 2021 Jun 1;32(3):191-199. doi: 10.1097/MOL.0000000000000750. PMID: 33900276. ↩
Lee HA, Kim HY. Therapeutic Mechanisms and Clinical Effects of Glucagon-like Peptide 1 Receptor Agonists in Nonalcoholic Fatty Liver Disease. Int J Mol Sci. 2023 May 26;24(11):9324. doi: 10.3390/ijms24119324. PMID: 37298276; PMCID: PMC10253495. ↩
Rizzo M, Nikolic D, Patti AM, Mannina C, Montalto G, McAdams BS, Rizvi AA, Cosentino F. GLP-1 receptor agonists and reduction of cardiometabolic risk: Potential underlying mechanisms. Biochim Biophys Acta Mol Basis Dis. 2018 Sep;1864(9 Pt B):2814-2821. doi: 10.1016/j.bbadis.2018.05.012. Epub 2018 May 18. PMID: 29778663. ↩
Wilding JPH, Batterham RL, et al. Efficacy of GLP-1 Receptor Agonists for Weight Loss in Adults With Obesity. N Engl J Med. 2025; [DOI: 10.1056/NEJMoa2416394]. ↩
Wegovy 0.25 mg, FlexTouch solution for injection in pre-filled pen – Summary of Product Characteristics (SmPC). Electronic Medicines Compendium. Available at: https://www.medicines.org.uk/emc/product/13799/smpc. Accessed November 2025. ↩
Mounjaro KwikPen 2.5 mg solution for injection in pre-filled pen – Summary of Product Characteristics (SmPC). Electronic Medicines Compendium. Available at: https://www.medicines.org.uk/emc/product/15481/smpc. Accessed November 2025. ↩
Rodriguez PJ, Goodwin Cartwright BM, Gratzl S, et al. Semaglutide vs Tirzepatide for Weight Loss in Adults With Overweight or Obesity. JAMA Intern Med. 2024;184(9):1056–1064. doi:10.1001/jamainternmed.2024.2525. ↩
Berg S, Stickle H, Rose SJ, Nemec EC. Discontinuing glucagon-like peptide-1 receptor agonists and body habitus: A systematic review and meta-analysis. Obes Rev. 2025 Aug;26(8):e13929. doi: 10.1111/obr.13929. Epub 2025 Apr 4. PMID: 40186344. ↩

Wegovy vs Mounjaro: Choosing the Right GLP-1 Treatment for Weight Loss and Wellness