Ozempic may have the market on name recognition when it comes to GLP-1 drugs for weight loss, but there is another medication that is actually more effective when it comes to shedding excess pounds — and its popularity is rising.
GLP-1 drugs account for seven percent of all prescriptions written nationwide and about 31 million Americans, or one in eight, are estimated to have used them at least once.
But now, new research from health data firm Truveta found that in a dataset of 120 million Americans, 1.2 percent were on semaglutide, sold as Ozempic and Wegovy, as of December 2025, the latest date available.
But nearly two percent were on tirzepatide, sold as Zepbound and Mounjaro.
Additionally, while prescriptions for semaglutide dropped 0.8 percent from August to December last year, those for tirzepatide surged 10 percent.
It’s a signal that Ozempic, although it started the weight loss drug boom, may now be being replaced by tirzepatide, which is less expensive and more effective.
Out of pocket, a monthly supply for semaglutide costs around $1,300 compared to $1,130 for tirzepatide.
In a 2024 study, researchers found that patients on Zepbound lost 21 percent of their body weight in 72 weeks, while those on Wegovy only lost 15 percent in about the same time period.
Tirzepatide was championed as the ‘King Kong’ of weight loss drugs, with doctors saying it was more effective because it mimics two hunger hormones, not just one as with semaglutide, which further slashes cravings.
Data suggests that tirzepatide has now overtaken semaglutide as the most popular weight loss drug in the US
Danish company Novo Nordisk manufactures semaglutide, which was first approved in the US in 2017 to be used in Ozempic. In June 2021, a different dose, called Wegovy, was approved for use.
Tirzepatide, manufactured by Eli Lilly, did not hit the market until May 2022, when Mounjaro was approved for type 2 diabetics. Its sister medication, Zepbound, was not approved until December 2024.
Tirzepatide has taken by celebrities including Rosie O’Donnell, 63, who lost 50lbs within two years while on Mounjaro. She said the drug was a ‘lifesaver’ and added in a May 2025 Instagram post: ‘I can’t believe this is me now’.
Whoopi Goldberg, 70, claimed to Daily Mail in October last year that she lost about 180lbs on Mounjaro over more than a year, after deciding to take the drug when her weight went over 300lbs.
She said: ‘I had to do those shots because I got sciatica. I had smashed the vertebrae in between the bones, doing something I told people specifically not to do, which was to run on wet grass.’
Whoopi Goldberg, 69, said she has lost the weight of ‘two people’. She is shown above in 2019 and after her weight loss. She took Mounjaro
Meghan Trainor, 32, revealed in April last year that she’d also used Mounjaro on her Workin’ On It podcast, saying there was ‘no shame’ in it because of the benefits it had for her health. In November 2022, Trainor said she had lost 60lbs after also making changes to her lifestyle and diet.
The data come just after the FDA approved a world-first pill version of Wegovy, the version of semaglutide approved for weight loss, in late December, in a move that may once again make the drug more popular than its rival.
In the research, Truveta scientists analyzed data on GLP-1 prescriptions from their nationally-representative dataset of 120 million people across the US.
Overall, they found that 2.2 million people in the dataset had been prescribed a GLP-1 since January 2019 for either diabetes, the drugs’ original purpose, or weight loss, while 11.2 million prescriptions for the drugs had been filled.
From September to December 2025, there was a five percent rise in prescribing rates overall.
Rosie O’Donnell, 63, has lost more than 50lbs within two years while taking Mounjaro, which contains tirzepatide. She is shown above in September 2022 (left) and July last year
Meghan Trainor, 31, looked nearly unrecognizable after she revealed she had lost 60lbs in a year. She has also revealed that she has taken Mounjaro. She is pictured above in 2020 and in November 2025
However, the number of first-time prescriptions for GLP-1s overall dropped 6.6 percent from August to December 2025.
In another sign that tirzepatide had now overtaken semaglutide, the data shows that prescriptions for the former were rising more rapidly.
They found that tirzepatide prescriptions were up 10 percent from August to December 2025. For Zepbound, prescriptions climbed 13.8 percent in the same period.
For comparison, semaglutide prescriptions fell 0.8 percent over the same period, while those for Wegovy only grew 2.3 percent.
There was a slowdown in the number of new users overall, but while they declined 1.6 percent for tirzepatide from August to December 2025, for semaglutide, they dropped by 11.8 percent.
Data from Truveta first showed that tirzepatide had overtaken semaglutide in March 2025, when about 1.4 percent of prescriptions were for tirzepatide compared to 1.2 percent for semaglutide. The gap has only grown since.
