- Zepbound led to more long-term weight loss than Wegovy in a new clinical trial from drugmaker Eli Lilly.
- Lilly officials said 31% of people taking Zepbound lost at least 25% of their body weight compared to 16% of study participants who took Wegovy.
- Experts note that weight loss drugs can only be effective if a person eats a healthy diet and engages in regular physical exercise.
Zepbound is more effective at long-term weight loss than Wegovy, according to clinical trial results released by drug manufacturer Eli Lilly.
Eli Lilly officials report that in their SURMOUNT-5 clinical trial Zepbound led to significant weight loss in 20% of study participants compared to nearly 14% in participants who took Wegovy.
They also reported that 31% of people taking Zepbound achieved at least 25% body weight loss compared to 16% for those taking Wegovy.
On average, people taking Zepbound lost about 50 pounds, while those taking Wegovy dropped about 33 pounds.
The phase 3b clinical trial included 751 people in the United States and Puerto Rico. The participants were either overweight or had obesity in addition to at least one other comorbidity, such as hypertension, obstructive sleep apnea, or cardiovascular disease. None of the participants was diagnosed with diabetes.
The participants were given a maximum tolerated dose of either Zepbound or Wegovy. The trial period lasted for 72 weeks.
Eli Lilly officials say they plan to publish these results in a peer-reviewed journal as well as present their findings at a major medical conference next year.
“Given the increased interest around obesity medications, we conducted this study to help healthcare providers and patients make informed decisions about treatment choice,” said Leonard Glass, MD, senior vice president of global medical affairs at Lilly Cardiometabolic Health, in a statement.
Should you take Zepbound or Wegovy?
Experts noted that this latest clinical trial backs up previous research showing the effectiveness of Zepbound.
“This is not new information. I have seen other studies demonstrating more effectiveness with Zepbound over Wegovy. Zepbound affects two hormone receptors (Wegovy affects one) to induce satiety and slow the GI tract,” said Mir Ali, MD, a bariatric surgeon and medical director of MemorialCare Surgical Weight Loss Center at Orange Coast Medical Center in California. Ali wasn’t involved in the clinical trial.
Ali noted that these findings may help people make a choice about which weight loss medication to take.
“The type of weight loss drug (or diabetes drug) can make a difference for some patients,” he told Healthline. “Some may be more sensitive to one medication or the other, and therefore, experience more side effects. Others may have more efficacy with one or the other. Additionally, some insurance providers may cover one medication and not the other.”
Dan Azagury, MD, the section chief of Minimally Invasive and Bariatric Surgery at Stanford University in California, said access to weight loss medications is the bigger issue. Azagury wasn’t involved in the clinical trial.
“The challenge we face right now is being able to give patients access to any medication. Insurance coverage is extremely challenging (not to mention shortages). At this point, if we can get a patient on either [Zepbound or Wegovy], it’s a win,” he told Healthline.
Weight loss drugs require commitment
Experts agree that a weight loss drug cannot be entirely effective unless a person eats a healthy diet and exercises regularly. Adequate sleep and stress reduction are also beneficial.
Ali said it’s important for people to know that weight loss drugs, even with a regimen of diet and exercise, are not quick fixes.
“Weight loss medications entail a long-term commitment. These medications are started at a low dose and slowly increased to allow the body to acclimate. Some patients do not see the expected weight loss results until they get to the higher doses,” he noted.
“It is also important for the patient to be aware that many patients will regain significant weight after stopping these medications.”
Azagury agreed that people taking weight loss drugs should be aware of the long-term commitment.
“They should be OK with the idea that it might be forever,” he said. “The vast majority of patients need to take it for life in order to avoid regaining weight. The only established way to get off the drug without significant weight regain is bariatric surgery.”
How weight loss drugs work
Zepbound, Wegovy, Ozempic, and Mounjaro are all drugs that are injected on a weekly basis.
Zepbound and Mounjaro are manufactured by Eli Lilly and contain the active ingredient tirzepatide. Zepbound is prescribed for weight management, while Mounjaro is prescribed to treat type 2 diabetes.
Ozempic and Wegovy are manufactured by Novo Nordisk and contain the active ingredient semaglutide.
Wegovy is prescribed for weight management and Ozempic is prescribed to treat type 2 diabetes.
All of them mimic the effects of the gut hormone GLP-1 to suppress the appetite of the person taking the medication.
Tirzepatide, the key ingredient in Zepbound and Mounjaro, stimulates the GIP and GLP-1 receptors.
Learn more about how to get GLP-1 medications like Zepbound and Mounjaro from vetted and trusted online sources here:
All weight loss drugs may come with side effects ranging from nausea to constipation to abdominal pain to fatigue. In severe cases, a person can have serious gastrointestinal issues.
Numerous studies have reported significant long-term weight loss benefits from the proper use of these medications.
There has also been research indicating these drugs can help prolong a person’s life by reducing their risk of cardiovascular disease and cancer.
In March 2024, the Food and Drug Administration gave Novo Nordisk permission to list heart-related benefits on Wegovy’s label.
In June 2024, results from a clinical trial indicated that Zepbound and Mounjaro may help reduce sleep apnea events.
In addition, some people with rheumatoid arthritis report that using GLP-1 drugs has helped reduce symptoms from their condition.
Takeaway
Eli Lilly officials reports their drug Zepbound is more effective than Wegovy for long-term weight loss.
In a clinical trial, 20% of Zepbound participants achieved significant weight loss, compared to nearly 14% of Wegovy participants.
The 72-week trial included 751 people who were either overweight or had obesity and at least one other comorbidity. None of the participants had been diagnosed with diabetes.
