Weight-loss medicines known as GLP-1 drugs have become some of the most talked-about medications in recent years.
Originally developed to treat type 2 diabetes, these medicines are now being used by millions of people who are trying to lose weight. Their popularity has grown so quickly that many people describe them as game-changing treatments for obesity.
A new study from the University of Georgia suggests that not all of these medicines work equally well for weight loss.
The research found that tirzepatide, sold under the brand names Zepbound for weight management and Mounjaro for type 2 diabetes, led to the greatest weight loss among the three approved GLP-1 medications examined. The findings were published in the journal Obesity.
The researchers conducted a large review and analysis of previous clinical trials. The study is the first meta-analysis to directly compare the effectiveness of three FDA-approved GLP-1 medicines in people without diabetes who were taking the medications specifically for weight loss.
The research team analyzed data from 15 phase 3 randomized controlled trials involving more than 14,000 participants. These studies are considered among the strongest types of medical evidence because participants are randomly assigned to different treatments and are carefully monitored.
The results showed that people taking tirzepatide lost more than 20 percent of their starting body weight on average. Participants using semaglutide, which is marketed as Wegovy for weight loss, lost around 15 percent of their body weight. People taking liraglutide, sold as Saxenda, lost about 8 percent of their starting weight.
The researchers were also interested in whether the medicines caused different levels of side effects. GLP-1 drugs are known to cause problems such as nausea, stomach upset, and digestive symptoms in some people.
The study found that tirzepatide produced the greatest weight loss without showing higher rates of these side effects compared with the other medicines.
Scientists believe tirzepatide’s impressive performance may be explained by how it works inside the body. Most weight-loss medicines in this group mainly copy the action of a natural hormone called glucagon-like peptide-1, or GLP-1.
This hormone helps lower blood sugar, slows the movement of food through the stomach, and makes people feel full for longer after eating.
Tirzepatide is different because it acts on both GLP-1 and another gut hormone called GIP. Researchers think this dual action may help increase feelings of fullness and improve the body’s ability to regulate appetite, leading to greater weight loss.
The findings are important because obesity has become one of the biggest health challenges worldwide. Carrying excess weight increases the risk of many serious health conditions, including type 2 diabetes, heart disease, high blood pressure, sleep apnea, and some forms of cancer.
Many people struggle to lose weight through diet and exercise alone because the body has powerful biological systems that defend against weight loss and often encourage weight regain.
This is one reason why medicines that reduce appetite have attracted so much attention. According to a recent survey by KFF, about one in eight Americans is currently taking a GLP-1 medication, and one in five has used one in the past.
However, the researchers caution that these medicines are not miracle cures. Previous studies have shown that many people regain weight after stopping treatment. The current study did not examine what happens after patients discontinue the medications, so important questions remain about long-term weight maintenance.
The study also highlighted some practical differences between the medications. Liraglutide was the least effective and requires daily injections. In contrast, tirzepatide and semaglutide are usually taken once a week, which many patients find more convenient.
The researchers also examined an oral form of semaglutide and found that it was nearly as effective as injectable semaglutide but still did not achieve the same degree of weight loss as tirzepatide.
Overall, the findings suggest that tirzepatide currently appears to be the most effective FDA-approved GLP-1 medication for weight loss in adults without diabetes. The strength of this study lies in its use of multiple high-quality clinical trials involving a large number of participants.
However, the analysis cannot answer every question. More research is needed to understand the long-term safety of these medications, whether patients can maintain weight loss after stopping treatment, and which groups of people benefit the most.
The findings provide encouraging evidence that newer obesity medicines can produce substantial weight loss, but they also remind us that obesity remains a complex condition that usually requires long-term management.
If you care about weight loss, please read studies that hop extract could reduce belly fat in overweight people, and early time-restricted eating could help lose weight .
For more health information, please see recent studies that Mediterranean diet can reduce belly fat much better, and Keto diet could help control body weight and blood sugar in diabetes.
Source: University of Georgia.
