Latest news with #LouisAronne
Medscape
24-06-2025
- Health
- Medscape
Combination Treatment Reduces Weight While Keeping Muscle
CHICAGO — Combined use of semaglutide with an investigational monoclonal antibody called bimagrumab produced significant fat mass loss while preserving lean mass, results from the phase 2b BELIEVE study found. Loss of muscle mass is an emerging concern with increasing use of GLP-1 agonists for weight loss as lean body mass is estimated to account for up to 15%-40% of total weight loss from GLP-1 drugs. One potential solution is bimagrumab, which blocks the activin pathways that inhibit growth in skeletal muscle and increases lipid storage in adipose tissue, leading to both increased muscle mass and decreased fat mass. 'We're presenting an entirely new mechanism for managing obesity. We've heard a lot about GLP-1s and their combinations. This is going to be a unique one with bimagrumab, a drug that has completely different mechanism of action,' study investigator Steven B. Heymsfield, MD, professor and director of the Body Composition-Metabolism Laboratory at the Pennington Biomedical Research Center of the Louisiana State University System, Baton Rouge, told Medscape Medical News . Results from the study comparing bimagrumab and semaglutide alone and in combination for treating obesity were presented on June 23, 2025, here at the American Diabetes Association 85th Scientific Sessions. Bimagrumab's effects are complementary to those of GLP-1 drugs and other appetite suppressants, explained co-investigator Louis J. Aronne, MD, professor of metabolic research and director of the Comprehensive Weight Control Center at Weill-Cornell Medical College, New York, at a press briefing. As such, he added, the drug's potential uses include being an adjunct to GLP-1 agonists for obesity induction therapy as an alternative to incretins for people who can't tolerate them or who don't respond adequately, and as a potential preferred maintenance therap. Fat Mass vs Muscle Mass The BELIEVE study was a randomized, double-blind, placebo-controlled, multicenter study in 507 adults with obesity or overweight. Participants were randomized into a total of nine groups: placebo; bimagrumab alone at doses of 10 mg/kg and 30 mg/kg; semaglutide 1.0 mg or 2.4 mg plus placebo; and one of four groups of combined bimagrumab and semaglutide — bimagrumab 10 mg/kg plus semaglutide 1 mg; bimagrumab 30 mg/kg plus semaglutide 1 mg; bimagrumab 10 mg/kg plus semaglutide 2.4 mg; or bimagrumab 30 mg/kg plus semaglutide 2.4 mg. Bimagrumab was given intravenously at weeks 4, 16, 28, and 40; subcutaneous semaglutide was given weekly. The primary treatment period was 48 weeks, followed by an open-label extension to 72 weeks with both the placebo and bimagrumab 10 mg/kg groups switching to bimagrumab 30 mg/kg. Body composition was assessed with DEXA. At week 72, body weight was reduced by 22.1% from baseline in the combined bimagrumab 30 mg/kg plus semaglutide 2.4 mg group (highest of both doses), compared with reductions of 15.7% with semaglutide 2.4 mg alone and 10.8% with bimagrumab 30 mg/kg alone. Loss of fat mass was 45.7% with the high-dose combination vs 27.8% with semaglutide 2.4 mg and 28.5% with bimagrumab 30 mg/kg alone. Lean mass loss was 2.9% with the high-dose combination, compared with a loss of 7.4% with semaglutide 2.4 mg and a gain of 2.5% with bimagrumab 30 mg/kg alone. The percentage of weight loss that was due to fat mass at week 48 was 92.9% for the high-dose combination, 71.5% for semaglutide alone, and 100% for bimagrumab alone. The proportions of participants achieving weight loss of 20% or more were 69.8% with the combination versus 25.0% with semaglutide, and 10.9% with bimagrumab. And, the proportions achieving 30% or greater fat mass reduction were 94.0%, 36.4%, and 50.0%, respectively, Heymsfield reported. Visceral adipose tissue decreased more with bimagrumab alone or in combination compared with semaglutide alone, with parallel changes from baseline in waist circumference. High-sensitivity C-reactive protein, a key inflammatory biomarker, decreased by 83% in the high-dose combination group by week 48, Aronne said. Adiponectin also increased more with bimagrumab alone or in combination compared with semaglutide alone. Both total and LDL cholesterol rose in the bimagrumab groups and then returned to baseline in the combination groups containing semaglutide 2.4 mg by week 72. Baseline LDL was 114.3 mg/dL, rising by about 15%-30% in the bimagrumab groups by 12-24 weeks. The combination groups returned to baseline by 72 weeks, whereas the bimagrumab-only group dropped, but not back to baseline. When asked about that, Aronne said 'We believe that the route of administration might be a reason for that observation. I think we need more research to figure this out.' Increased LDL Cholesterol: Is It a Concern? Asked to comment, Simeon Taylor, MD, PhD, professor of medicine and director of the Institutional Research Training Program in Diabetes & Obesity at the University of Maryland School of Medicine, Baltimore, told Medscape Medical News that the efficacy data were 'amazing,' and that the combination 'delivered unprecedented efficacy as judged by biomarkers, specifically the combination of loss of fat mass plus the increase in lean mass. These changes were accompanied by clinically meaningful improvements in blood pressure and glycemic indices. It will be critical to understand the impact on 'hard' clinical endpoints such as cardiovascular outcomes.' However, Taylor added that the trial raised some safety concerns, particularly an increase in LDL cholesterol that the investigators said was transient, but they didn't present data about what measures might have been used by the individual clinicians in the study to mitigate that rise. 'It will be important for the investigators to clarify how statin doses were managed. If the adverse effects of bimagrumab were transient, that could be a favorable scenario. If the LDL cholesterol returned toward baseline because statin doses were increased, that would have different implications,' he said. Obesity expert Amy E. Rothberg, MD, clinical professor of internal medicine and of nutritional sciences at the University of Michigan, Ann Arbor, agreed, and also cited other missing information, such as muscle quality. 'There were no biopsies done. They were doing DEXA. That tells us about distribution and volume, but it doesn't tell us anything about quality.' Rothberg also noted that the only objective functional measure was hand grip, while the rest were self-administered survey instruments. 'There are a lot of unknowns, but impressive data just the same.' Hard to Predict Safety Concerns Common adverse events with bimagrumab-containing groups included muscle spasms (ranging from 46.4% with 10 mg to 63.6% with the high-dose combination), diarrhea, and acne, while semaglutide was associated with the typical nausea, diarrhea, constipation, and fatigue. Similar events occurred in the four combination groups, in which 9% of those treated discontinued due to adverse events over 72 weeks. There were no deaths. The bimagrumab-containing groups showed early and transient increases in alanine aminotransferase and lipase, while semaglutide-containing groups had sustained increases in lipase. 'The biology of activin receptors is extremely complex. It is hard to predict all of the possible safety concerns. Phase 3 studies and pharmacovigilance will provide better understanding,' Taylor told Medscape Medical News . 'Some potential safety issues only become apparent when large numbers of people have taken the drug for long periods of time, he said, adding that 'obesity drugs are understandably required to have a very 'clean' safety profile.' The BELIEVE phase 2 study was essentially proof-of-concept, said Heymsfield. Semaglutide is a product of Lilly competitor Novo Nordisk. This unusual situation came about because the study was initiated in 2023 by Versanis Bio, which Lilly later acquired. Lilly is now conducting phase 2 trials of bimagrumab with its own GLP-1-based drug tirzepatide, this time co-formulated with bimagrumab in a subcutaneous injection. Heymsfield has a contract with Lilly for clinical trials (institutional support). He has received honoraria for serving on medical advisory boards of Tanita Corporation, Novo Nordisk, Lilly, Regeneron, Abbott, and Medifast. He is on the Data Safety Monitoring Committee for Novo Nordisk. Aronne receives consulting fees from/and serving on advisory boards for Altimmune, Atria, Eli Lilly, Jamieson Wellness, Janssen Pharmaceuticals, Jazz Pharmaceuticals, Juvena Therapeutics, Kallyope, Novartis, Novo Nordisk, Pfizer, Prosciento, Senda Biosciences, Versanis, Veru Pharmaceuticals, and Zealand Pharmaceuticals; receives research funding from AstraZeneca, United Kingdom, Eli Lilly, Janssen Pharmaceuticals, Belgium, and Novo Nordisk, Denmark; having equity interests in ERX Pharmaceuticals, Intellihealth, Jamieson Wellness, Kallyope, Myos Corp, and Veru Pharmaceuticals; and serves on a board of directors for ERX Pharmaceuticals, Intellihealth, and Jamieson Wellness. Taylor has reported receiving payments from the National Institute of Diabetes and Digestive and Kidney Diseases for an inventor's share of a patent covering metreleptin as a treatment for generalized lipodystrophy. He was employed by Eli Lilly in 2000-2002 and Bristol Myers Squibb in 2002-2013.
Toronto Sun
23-06-2025
- Health
- Toronto Sun
Lilly drug saves muscle when added to Wegovy weight-loss shot
The findings offer a potential solution to one of the key problems that's emerged with popular obesity shots Published Jun 23, 2025 • 1 minute read A Wegovy injection pen arranged in Waterbury, Vermont, US, on Monday, April 28, 2025. Photo by Shelby Knowles / Bloomberg Reviews and recommendations are unbiased and products are independently selected. Postmedia may earn an affiliate commission from purchases made through links on this page. Patients who took an experimental drug from Eli Lilly & Co. together with Novo Nordisk A/S's Wegovy maintained muscle while losing weight, offering a potential solution to one of the key problems that's emerged with popular obesity shots. This advertisement has not loaded yet, but your article continues below. THIS CONTENT IS RESERVED FOR SUBSCRIBERS ONLY Subscribe now to read the latest news in your city and across Canada. Unlimited online access to articles from across Canada with one account. Get exclusive access to the Toronto Sun ePaper, an electronic replica of the print edition that you can share, download and comment on. Enjoy insights and behind-the-scenes analysis from our award-winning journalists. Support local journalists and the next generation of journalists. Daily puzzles including the New York Times Crossword. SUBSCRIBE TO UNLOCK MORE ARTICLES Subscribe now to read the latest news in your city and across Canada. Unlimited online access to articles from across Canada with one account. Get exclusive access to the Toronto Sun ePaper, an electronic replica of the print edition that you can share, download and comment on. Enjoy insights and behind-the-scenes analysis from our award-winning journalists. Support local journalists and the next generation of journalists. Daily puzzles including the New York Times Crossword. REGISTER / SIGN IN TO UNLOCK MORE ARTICLES Create an account or sign in to continue with your reading experience. Access articles from across Canada with one account. Share your thoughts and join the conversation in the comments. Enjoy additional articles per month. Get email updates from your favourite authors. THIS ARTICLE IS FREE TO READ REGISTER TO UNLOCK. Create an account or sign in to continue with your reading experience. Access articles from across Canada with one account Share your thoughts and join the conversation in the comments Enjoy additional articles per month Get email updates from your favourite authors Don't have an account? Create Account The closely-watched study showed that patients on Wegovy combined with bimagrumab lost 22.1% of their body weight in 48 weeks, with 92.8% of that coming from the body's fat stores, according to results shared Monday at the American Diabetes Association conference in Chicago. Those on Wegovy alone lost 15.7% of their weight, with 71.8% coming from body fat — indicating more muscle was lost when the experimental drug wasn't included in the regimen. 'This is the result we were hoping for,' said study lead Louis Aronne, a physician who directs the Comprehensive Weight Control Center at Weill Cornell Medicine. The trial was funded by Lilly, which bought bimagrumab for about $2 billion in 2023 from startup Versanis Bio. Lilly is now running additional studies of bimagrumab in combination with its own obesity shot, Zepbound. This advertisement has not loaded yet, but your article continues below. When people drop weight quickly, whether via obesity drugs or bariatric surgery, they tend to lose muscle alongside fat. That's raised concerns, particularly for people over 65, who take weight-loss drugs. It's also made muscle preservation an alluring target for drugmakers like Regeneron Inc. and biotech Veru Inc., which are seeking a foothold in the fast-growing and lucrative obesity market. Additional drug combinations may carry a risk of more side effects though, raising concerns from some doctors. Regeneron recently said that a combination of Wegovy and two other experimental drugs spurred more weight loss, while preserving muscle for patients enrolled in its trial. However, about 28% of patients dropped out of the trial and two patients receiving the drugs died. Regeneron said it 'has not identified a causal association' between the drugs and deaths. Still, Bloomberg Intelligence analysts called the result 'unnerving.' Toronto & GTA Toronto Maple Leafs Sunshine Girls Sunshine Girls MLB
Yahoo
26-05-2025
- Health
- Yahoo
Study directly compares Zepbound and Wegovy for weight-loss results
Weight-loss medications continue to grow in popularity as an anti-obesity tool — but are some more effective than others? The question was explored in a new study published this month in The New England Journal of Medicine. Researchers compared the safety and efficacy of tirzepatide (brand name Zepbound) and semaglutide (brand name Wegovy) in a 72-week clinical trial. Weight-loss Medications May Also Benefit Common Medical Problem, Study Finds The randomized, controlled trial — called SURMOUNT-5 — included 751 people throughout the U.S. and Puerto Rico who had obesity but not type 2 diabetes. "Doctors, insurance companies and patients are always asking, 'Which drug is more effective?'" said Dr. Louis Aronne, director of the Comprehensive Weight Control Center and the Sanford I. Weill Professor of Metabolic Research at Weill Cornell Medicine, in the release. "This study allowed us to do a direct comparison." Read On The Fox News App "The results are consistent with — in fact, almost identical to — what we've seen in trials in which these drugs were evaluated independently," added Aronne, who was a principal investigator in the trial. The study found that tirzepatide achieved greater weight loss, with participants shedding about 50 pounds (20.2% of their body weight). The group taking semaglutide lost an average of 33 pounds or 13.7% of their baseline weight, according to a press release summarizing the study outcome. Overall, 32% of the people taking tirzepatide lost at least 25% of their body weight; semaglutide users lost around 16%. Weight Loss, Diabetes Drugs Can Cause Mood Changes: What To Know About Behavioral Side Effects Tirzepatide users also reported a "greater reduction in waist circumference" than those on semaglutide. The likely reason for tirzepatide's greater effectiveness is that it uses a "dual mechanism of action," according to Aronne. "Whereas semaglutide works by activating receptors for a hormone called glucagon-like peptide 1, or GLP-1, tirzepatide mimics not only GLP-1, but also an additional hormone, glucose-dependent insulinotropic peptide (GIP)," the release stated. "Together, these actions reduce hunger, lower blood-glucose levels and affect fat cell metabolism." Weight-loss Drugs' Impact On Cancer Risk Revealed In New Study Additional trials are actively exploring whether tirzepatide also reduces the risk of heart attack and stroke, a benefit that has been linked to semaglutide. The study was led by an investigator at Weill Cornell Medicine and NewYork-Presbyterian. It was also conducted with the University of Texas McGovern Medical School, the David Geffen School of Medicine at the University of California, Los Angeles, the University College Dublin and Eli Lilly (maker of Zepbound). The participants all received guidance regarding nutrition and exercise. The reported side effects were very similar for the two drugs, with 44% of people experiencing nausea and 25% having abdominal pain. Weight-loss Drugs To Get Surprising Endorsement From Global Health Giant Dr. Ada Londono, M.D., a board-certified obesity and internal medicine primary care physician with PlushCare — a virtual health platform offering primary care, therapy and weight management services — said she was not surprised by the study's findings. "The results are consistent with prior trials, confirming tirzepatide's advantage over semaglutide's single GLP-1 action," Londono, who is based in New York City, told Fox News Digital. Beyond weight loss, semaglutide has also shown potential benefits for cardiovascular health, sleep apnea and kidney disease, she noted. "These findings highlight the need for continued research to understand tirzepatide's broader health impacts," she said. "It's encouraging to see ongoing studies exploring the full potential of GLP-1 medications beyond weight management." Londono said these treatments can come with side effects. Semaglutide Found To Have Shocking Benefit For Liver Disease Patients In New Study "Most people on these medications only report mild symptoms, but some have experienced more serious reactions, such as pancreatitis," she told Fox News Digital. "This underscores the importance of reviewing your medical history and discussing any concerns with your healthcare provider." The study did have some limitations — chiefly that it was not a blinded analysis and participants knew which medication they were receiving. This could introduce some level of bias, the researchers acknowledged. Londono pointed out that while the study's findings are "promising," it was funded by Eli Lilly, the manufacturer of Zepbound. "This may raise questions about potential conflicts of interest," she said. "Additionally, the open-label design and 72-week duration may limit objectivity and long-term insight." While the study primarily looked at the impact of the medications, experts agreed there are other factors that play a role in successful weight management. "Weight loss is biological, but it's also emotional, and whole-person support can make the difference between short-term results and sustainable health," Dr. Rekha Kumar, chief medical officer at the weight care program Found and a practicing endocrinologist in New York City, told Fox News Digital. Kumar emphasized the importance of working with a physician to choose a weight-loss medication that matches the patient's personal goals and health status. "For example, if a patient has fatty liver, we will choose the GLP-1 that is proven to work best for liver disease," she said. Looking ahead, the researchers plan to investigate new versions of weight-loss drugs, including retatrutide, which mimics the hormones GLP-1, GIP and glucagon, according to the release. Click Here To Sign Up For Our Health Newsletter "Even though drugs like tirzepatide and semaglutide work really well, better than anything we have ever seen, we still have people who don't respond to them," said Aronne. "So, moving forward, we want to keep trying to do better." A spokesperson from Novo Nordisk, the company that makes Wegovy (semaglutide), sent a statement to Fox News Digital. "Across the respective clinical trial programs and in SURMOUNT-5, both Wegovy and Zepbound have demonstrated clinically significant weight reduction," the company said. "It is important to recognize that the comprehensive management of obesity goes beyond weight reduction alone." For more Health articles, visit The spokesperson also pointed out that in a previous trial, adults who were obese or overweight and who took Wegovy along with diet and exercise lost an average of 15.2% of their weight (~35 pounds) at the two-year mark, compared with 2.6% (~6 pounds) for patients taking a article source: Study directly compares Zepbound and Wegovy for weight-loss results
Fox News
26-05-2025
- Health
- Fox News
Study compares Zepbound and Wegovy for weight loss in direct comparison
Weight-loss medications continue to grow in popularity as an anti-obesity tool — but are some more effective than others? The question was explored in a new study published this month in The New England Journal of Medicine. Researchers compared the safety and efficacy of tirzepatide (brand name Zepbound) and semaglutide (brand name Wegovy) in a 72-week clinical trial. The randomized, controlled trial — called SURMOUNT-5 — included 751 people throughout the U.S. and Puerto Rico who had obesity but not type 2 diabetes. "Doctors, insurance companies and patients are always asking, 'Which drug is more effective?'" said Dr. Louis Aronne, director of the Comprehensive Weight Control Center and the Sanford I. Weill Professor of Metabolic Research at Weill Cornell Medicine, in the release. "This study allowed us to do a direct comparison." "The results are consistent with — in fact, almost identical to — what we've seen in trials in which these drugs were evaluated independently," added Aronne, who was a principal investigator in the trial. The study found that tirzepatide achieved greater weight loss, with participants shedding about 50 pounds (20.2% of their body weight). "Doctors, insurance companies and patients are always asking, 'Which drug is more effective?'" The group taking semaglutide lost an average of 33 pounds or 13.7% of their baseline weight, according to a press release summarizing the study outcome. Overall, 32% of the people taking tirzepatide lost at least 25% of their body weight; semaglutide users lost around 16%. Tirzepatide users also reported a "greater reduction in waist circumference" than those on semaglutide. The likely reason for tirzepatide's greater effectiveness is that it uses a "dual mechanism of action," according to Aronne. "Whereas semaglutide works by activating receptors for a hormone called glucagon-like peptide 1, or GLP-1, tirzepatide mimics not only GLP-1, but also an additional hormone, glucose-dependent insulinotropic peptide (GIP)," the release stated. "Together, these actions reduce hunger, lower blood-glucose levels and affect fat cell metabolism." Additional trials are actively exploring whether tirzepatide also reduces the risk of heart attack and stroke, a benefit that has been linked to semaglutide. The study, which was led by an investigator at Weill Cornell Medicine and NewYork-Presbyterian, was also conducted with the University of Texas McGovern Medical School, the David Geffen School of Medicine at the University of California, Los Angeles, the University College Dublin and Eli Lilly (maker of Zepbound). The participants all received guidance regarding nutrition and exercise. The reported side effects were very similar for the two drugs, with 44% experiencing nausea and 25% having abdominal pain. Dr. Ada Londono, MD, a board-certified obesity and internal medicine primary care physician with PlushCare — a virtual health platform offering primary care, therapy and weight management services — said she was not surprised by the study's findings. "The results are consistent with prior trials, confirming tirzepatide's advantage over semaglutide's single GLP-1 action," Londono, who is based in New York City, told Fox News Digital. Beyond weight loss, semaglutide has also shown potential benefits for cardiovascular health, sleep apnea and kidney disease, she noted. "These findings highlight the need for continued research to understand tirzepatide's broader health impacts," she said. "It's encouraging to see ongoing studies exploring the full potential of GLP-1 medications beyond weight management." Londono pointed out that these treatments can come with side effects. "Most people on these medications only report mild symptoms, but some have experienced more serious reactions, such as pancreatitis," she told Fox News Digital. "This underscores the importance of reviewing your medical history and discussing any concerns with your healthcare provider." The study did have some limitations — chiefly that it was not a blinded analysis and participants knew which medication they were receiving. This could introduce some level of bias, the researchers acknowledged. Londono pointed out that while the study's findings are "promising," it was funded by Eli Lilly, the manufacturer of Zepbound. "This may raise questions about potential conflicts of interest," she said. "Additionally, the open-label design and 72-week duration may limit objectivity and long-term insight." While the study primarily looked at the impact of the medications, experts agreed that there are other factors that play a role in successful weight management. "Weight loss is biological, but it's also emotional, and whole-person support can make the difference between short-term results and sustainable health," Dr. Rekha Kumar, chief medical officer at the weight care program Found and a practicing endocrinologist in New York City, told Fox News Digital. Kumar emphasized the importance of working with a physician to choose a weight-loss medication that matches the patient's personal goals and health status. "Both Wegovy and Zepbound have demonstrated clinically significant weight reduction." "For example, if a patient has fatty liver, we will choose the GLP-1 that is proven to work best for liver disease," she said. Looking ahead, the researchers plan to investigate new versions of weight-loss drugs, including retatrutide, which mimics the hormones GLP-1, GIP and glucagon, according to the release. "Even though drugs like tirzepatide and semaglutide work really well, better than anything we have ever seen, we still have people who don't respond to them," said Aronne. "So, moving forward, we want to keep trying to do better." A spokesperson from Novo Nordisk, the company that makes Wegovy (semaglutide), sent the below statement to Fox News Digital. "Across the respective clinical trial programs and in SURMOUNT-5, both Wegovy and Zepbound have demonstrated clinically significant weight reduction. It is important to recognize that the comprehensive management of obesity goes beyond weight reduction alone." For more Health articles, visit The spokesperson also pointed out that in a previous trial, adults with obesity or overweight who took Wegovy along with diet and exercise had lost an average of 15.2% of their weight (~35 pounds) at the two-year mark, compared with 2.6% (~6 pounds) for patients taking a placebo.
Irish Examiner
20-05-2025
- Health
- Irish Examiner
Weight-loss jab Mounjaro helps people shed much more weight than rival
Weight-loss jab Mounjaro – dubbed the 'King Kong' of similar medicines – helps people shed significantly more weight than rival Wegovy, new research suggests. Key research pitching the drugs against each other found Mounjaro was superior when it came to shedding pounds and losing inches, though both drugs worked. Experts presented their findings at the European Congress on Obesity in Malaga and published them in the New England Journal of Medicine. Both Mounjaro (tirzepatide) and Wegovy (semaglutide) are weight-loss medicines that make people feel fuller for longer and therefore less hungry. The new randomised controlled trial involved 751 adult with obesity, but without type 2 diabetes. They received either Mounjaro at the maximum tolerated dose (10mg or 15mg) or Wegovy (1.7mg or 2.4mg) once a week for 72 weeks. The typical age of the people was 45 and most (65%) were female, with a typical body mass index (BMI) of 39. All had at least one known obesity-related complication, such as high blood pressure, sleep apnoea or heart disease. The typical drop in body weight at the end of the trial was a 20.2% reduction with Mounjaro and 13.7% with Wegovy, showing Mounjaro was superior. The drop in waist circumference was also 18.4cm on average with Mounjaro and 13cm with Wegovy. People on Mounjaro were more likely to reach their weight loss goals. One limitation to the study was that people knew which drug they were taking, though the researchers said the findings were in line with previous studies. The research was sponsored by Eli Lilly and Company, the manufacturer of Mounjaro. Our study shows that treatment with tirzepatide was superior to semaglutide with respect to reduction in body weight and waist circumference Dr Louis Aronne, from Weill Cornell Medicine in New York, who led the work, said the dual action of Mounjaro may explain the findings. Both Mounjaro and Wegovy mimic a hormone produced in the body called GLP-1 – a substance that is released in the gut when people consume food. This hormone slows the rate at which food is emptied from the stomach, reduces appetite via the brain and works on insulin levels. But Mounjaro also mimics another hormone known as GIP (glucose-dependent insulinotropic polypeptide). Dr Aronne said: 'Our study shows that treatment with tirzepatide was superior to semaglutide with respect to reduction in body weight and waist circumference. 'Tirzepatide, while a single molecule, pharmacologically activates two metabolic receptors, GIP and GLP-1, which have both overlapping and non-overlapping expression and function. 'This dual agonism of tirzepatide may contribute to the higher weight reduction observed in the current study compared to semaglutide, a mono-agonist.' As people lost weight in the study, health factors such as blood pressure and unhealthy blood fats all improved. Speaking at the European Congress on Obesity in Malaga, Spain on Sunday, Dr Aronne said: 'This is actually the first head-to-head trial of two obesity medications, so I think we're going to start seeing more of these as new medications become available. 'I saw a list the other day of 150 medications… that are now in development, so many people now realise how important it is to manage body weight in addition to other metabolic factors. 'I've called it the golden age of obesity treatment. It took a long time!' Dr Aronne said semaglutide still remained an 'extremely effective' weight loss medication and that the trial did not intended to minimise its effects. He added: 'For example, if you have a patient with a BMI of 32, which is class one obesity, they could get to a BMI in the mid 20s, right around 25 (with semaglutide), which is normal. 'So the majority of people with obesity will do just fine on semaglutide. People at the higher end – class two, class three obesity – may ultimately do better with tirzepatide.'
