Ozempic has become a blockbuster medication thanks to its ability to help people lose weight, but another Type 2 diabetes treatment is poised to challenge the drug in the weight-loss arena.
Tirzepatide, which is sold under the brand name Mounjaro, has now shown striking results in two clinical trials.
The once-weekly injectable prescription medication helped obese or overweight people with Type 2 diabetes lose up to 15% of their body weight, or 34 pounds, drug maker Eli Lilly announced on Apr. 27.
That compares to a 3% weight loss, or 7 pounds on average, for patients taking a placebo, according to the trial results. The study followed more than 900 adults who were randomly assigned to get either a placebo or one of two dose strengths of tirzepatide for 17 months.
Weight loss can be hard for people with diabetes because of the way their body responds to insulin, so the medication could be “extremely helpful” for patients with Type 2 diabetes who need to slim down, Dr. Shauna Levy, medical director of the Tulane Bariatric Center in New Orleans, told NBC News. She was not involved in the trial.
Striking weight loss
The results come less than a year after another trial found tirzepatide helped overweight or obese patients without diabetes lose up to almost a quarter of their body weight, or 22%, after 17 months compared to a 2% weight loss with a placebo.
Those are the kinds of results doctors see with gastric bypass surgery, NBC news medical contributor Dr. Natalie Azar said when the findings were released.
“We need this tool in the toolbox,” she noted. “It’s so important and so relevant. The majority of Americans are either overweight or obese.”
In comparison, Wegovy, the version of Ozempic approved for weight loss by the U.S. Food and Drug Administration, helped patients lose an average of 12% of their initial body weight after 16 months compared to those who received placebo.
When asked if patients have to keep taking the drug to maintain weight loss, Eli Lilly said an upcoming trial will evaluate the efficacy and safety of tirzepatide for maintenance of weight loss in overweight or obese adults. Results are expected later this year, the company noted in a statement.
If tirzepatide is approved for weight loss by the FDA — a decision that Eli Lilly expects could come this year — it could become the best-selling drug of all time, NBC News reported.
Will it make people forget about Ozempic or Wegovy?
“I don’t think so,” Dr. Louis Aronne, director of the Comprehensive Weight Control Center at Weill Cornell Medicine and NewYork-Presbyterian, tells TODAY.com. He’s a scientific adviser for Eli Lilly and Novo Nordisk, which makes Ozempic and Wegovy.
“Having more medications that are slightly different is a good thing because some people may respond better to one and some may respond better to another.”
How does tirzepatide work?
Tirzepatide works in a similar way to semaglutide, the active ingredient in Ozempic and Wegovy. They’re all in a class of drugs called GLP-1 agonists and mimic the effects of a hormone the body releases when people eat food. Patients have reduced appetite, and when they do eat, they feel full sooner.
But tirzepatide also mimics a second hormone, called GIP, which may improve how the body breaks down sugar and fat in addition to reducing appetite, NBC News reported.
Studies have found there’s a “synergistic action” when the body’s receptors for both GIP and GLP-1 are activated, leading to greater weight loss.
Jennifer Huber of North Port, Florida, has been taking Mounjaro for almost a year to treat her Type 2 diabetes. She was surprised to lose about 60 pounds.
“It has changed my life,” Huber told NBC News. “Even though I’m a smaller person now, I feel that I’m more visible in society. It’s been a good thing.”
What are the side effects?
She said she’s had side effects including nausea and constipation. Other common side effects of Mounjaro include diarrhea, vomiting, indigestion and stomach pain, according to Eli Lilly.
Serious side effects of the drug include pancreatitis, low blood sugar, serious allergic reactions, kidney problems, vision changes and gallbladder problems, the company noted in the news release.
Huber is also worried she’ll gain the weight back if she stops taking Mounjaro.
Dr. Christopher McGowan, an obesity medicine specialist in Cary, North Carolina, who has prescribed Mounjaro off-label for weight loss in the past says weight recurrence is “near-universal” after patients stop using the drug.
“This is identical to what we see after cessation of Wegovy, Ozempic, or any GLP-1 medication, for that matter,” McGowan tells TODAY.com.
“These medications, while potent and highly effective for the treatment of weight, must be continued indefinitely, or weight recurrence is inevitable. They are a treatment, not a cure.”
Huber also doesn’t know if her health insurance will continue to cover the drug. The list price of Mounjaro is about $1,023 per fill, which is equal to a month’s supply or four injector pens, according to Eli Lilly.
Wegovy has a list price of $1,349 for a month’s supply. Patients have to keep taking it for the drug to work, otherwise they will regain two-thirds of their prior weight loss, studies have shown.
Dr. Zhaoping Li, professor of medicine and chief of the division of clinical nutrition at the University of California, Los Angeles, says she doesn’t think drugs like tirzepatide or semaglutide are the solution to the obesity epidemic. Almost 42% of adults in the U.S. are obese, according to the Centers for Disease Control and Prevention.
Bariatric surgery, which leads to much substantial weight loss, has been around for years and hasn’t moved the needle that much, Li points out, noting that many patients eventually gain the weight back.
People must learn healthy eating habits for long-term weight loss, she says.
“I really don’t think we can help our patients just with a prescription — giving it to them without doing the fundamentals,” Li tells TODAY.com.
“It’s not realistic to think that from this point on, you can give yourself shots for the rest of your life without any problems.”
Tirzepatide for weight loss was studied in the context of a reduced-calorie diet and increased physical activity, Eli Lilly said. Wegovy is also meant to be used in addition to eating less and moving more, the FDA notes.