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Data from new trials found that people who took Mounjaro lost 26.6% of their body weight over 84 weeks. Sandy Huffaker for The Washington Post via Getty Images
  • Diabetes drug tirzepatide, also known by the brand name Mounjaro, has achieved impressive results as a weight loss treatment.
  • The latest clinical trials show Mounjaro was more effective than Ozempic, with patients achieving 26.6% weight loss over 84 weeks.
  • Mounjaro promotes weight loss by improving satiety, breaking down fat, and reducing sugar cravings.
  • The drug has similar side effects to Ozempic, including nausea, vomiting, abdominal pain, and constipation.

Type 2 diabetes treatment Ozempic has been making waves in recent months as a weight loss treatment. But another drug has emerged as an alternative treatment, and according to new research, it boasts better results.

New trials for Mounjaro, a hormone-mimicking diabetes treatment that contains tirzepatide, show that it may be even more effective for weight loss than Ozempic.

The SURMOUNT-3 and SURMOUNT-4 trials conducted by Eli Lilly found that when taking tirzepatide (Mounjaro), patients with obesity experienced 26.6% weight loss over the course of 84 weeks.

By comparison, Ozempic has been shown to help patients lose up to 15% of their body weight.

It’s worth noting that patients on the SURMOUNT-3 trial also underwent an intensive lifestyle intervention that included a low calorie diet, exercise, and weekly counseling sessions.

“The results of SURMOUNT-3 and -4 showed the highest level of weight loss observed in the SURMOUNT program to date,” Dr. Jeff Emmick, Ph.D., senior vice president of product development at Eli Lilly said in a statement. “Whether taking tirzepatide for 88 weeks in SURMOUNT-4 or taking tirzepatide for 72 weeks following intensive caloric restriction in SURMOUNT-3, participants achieved similar mean weight reduction — about 26%.”

He added that the findings from SURMOUNT-3 challenge the notion that patients living with obesity can achieve their weight loss goals with diet and exercise alone.

Similarly, he said that results from SURMOUNT-4 “reinforce that obesity should be regarded like other chronic diseases where chronic therapy may be needed to maintain treatment benefits.”

“These trials establish tirzepatide as the main frontrunner in the landscape of anti-obesity medications,” says Dr. Beverly Tchang, assistant professor of medicine, endocrinologist, and advisor at Ro.

Theorizing why tirzepatide may be more effective for weight loss than Ozempic, Tchang explains that Tirzepatide is a dual GLP-1/GIP receptor agonist. This means it increases the activity of gut peptides that promote satiety, while GIP also stimulates lipolysis – the breakdown of fat.

“We think tirzepatide’s weight loss effect is driven more by the GIP component than the GLP-1 effects, and this may be the reason why we are seeing more weight loss from tirzepatide than with other medications, which are only GLP-1 agonists,” she surmises.

By targeting both the GLP-1 and GIP agonists, tirzepatide has an impact on appetite and blood sugar regulation. It also increases insulin sensitivity and makes insulin production more efficient. This means you are satisfied more quickly and don’t feel the need to keep eating.

Nutritionist Jane Hutton notes that it can also slow digestion and food transit, meaning you feel fuller for longer.

“It would seem that tirzepatide reduces appetite considerably by creating fullness, cutting sugar cravings (often caused by high sugar diets and a rollercoaster blood sugar levels), and maintaining energy levels,” she explains.

People would feel good and could therefore be inclined to make healthier food choices and eat less,” she adds.

As with any treatment, there are always side effects to consider and there has been a lot of discussion about the potential side effects posed by Ozempic, which can include:

Hutton says both drugs appear to have similar side effects.

“Both Mounjaro and Ozempic slow digestion and reduce stomach acid. This is what causes the gastrointestinal side effects, and the issues with fat digestion experienced by many who take these drugs,” she explains. “Some people will be able to tolerate this gastrointestinal impact, but others won’t.”

Mounjaro also carries a small risk of thyroid C-cell tumors and more serious side effects like pancreatitis or gallbladder disease, on the order of 1% or less.

Additionally, women taking oral contraceptives are advised to switch to a non-oral birth control method for four weeks after starting the drug and four weeks after each dose escalation.

When it comes to side effects, Hutton believes you need to weigh up the pros and cons between the potential risks of taking a drug and the effort of making long-term sustainable changes yourself.

“Drugs can potentially have far more risk when it comes to knock-on effects and damage to organs and metabolic functions than a diet can,” she points out.

“Tirzapetide is already listing warnings of negatively affecting the thyroid, pancreas, kidneys, stomach, and gallbladder – all organs of digestion and waste removal,” Hutton adds.

There’s still a lot we don’t know about Mounjaro when used long-term. Questions also remain about potential weight gain once you stop using it.

“If your mental, emotional, and physical habits are not changed, you will not keep a significant amount of weight off, especially in the long term,” Hutton warns.

She believes the question to ask before considering any of these drugs is why you feel you need them.

“Would you take it if you knew it would turn out to have permanently affected your digestion or your kidneys? What will you do when you finish taking it? What is stopping you from losing weight naturally with food and nutrition?” she asks. “All of these are crucial questions. In my opinion, we are on the verge of normalizing taking serious drugs to do what we should be able to do with the right food, nutrition knowledge, and a healthy lifestyle.”

Whether you choose to lose weight by going it alone or with the help of drugs like Mounjaro or Ozempic, you’ll still need to address what led you to gain weight if you’re to keep it off long-term.

Diabetes drug tirzepatide has achieved impressive results as a weight loss treatment in the latest clinical trials.

The drug, which is also known by the brand name Mounjaro, was found to be more effective than Ozempic, with patients achieving 26.6% weight loss over 84 weeks.

The drug promotes weight loss by improving satiety, breaking down fat, and reducing sugar cravings.

Mounjaro has similar side effects to Ozempic, including nausea, vomiting, abdominal pain, and constipation.