Recent evaluations commissioned by the World Health Organization have confirmed that glucagon-like peptide-1 (GLP-1) receptor agonists, including tirzepatide (marketed as Mounjaro and Zepbound), semaglutide (available as Ozempic and Wegovy), and liraglutide (known as Victoza and Saxenda), can lead to significant weight loss among individuals with obesity. The findings, published in three comprehensive reviews by Cochrane, highlight both the potential benefits and notable concerns regarding these medications.
The reviews focused on the effectiveness of GLP-1 drugs in promoting weight loss compared to placebos. Each of the medications demonstrated greater reductions in body weight over one to two years. Despite these promising results, researchers noted a lack of long-term safety data and common side effects, including nausea and digestive issues, which led some participants to discontinue treatment.
Weight Loss Results and Safety Concerns
As the research indicates, GLP-1 drugs are designed to mimic a naturally occurring hormone that slows digestion and promotes feelings of fullness. Initially developed for the treatment of type 2 diabetes, these medications have gained traction for their role in weight management. They are currently approved in the United Kingdom for individuals with obesity or those who are overweight and have related health conditions, provided they also follow a reduced-calorie diet and engage in physical exercise.
According to the analysis, participants using tirzepatide, semaglutide, and liraglutide experienced substantial weight loss when compared to those on placebo. However, researchers found no significant differences regarding major cardiovascular events, quality of life, or mortality rates between the medication users and placebo groups.
Dr. Juan Franco, co-lead researcher from Heinrich Heine University Düsseldorf, expressed optimism about these findings, stating, “These drugs have the potential to bring about substantial weight loss, particularly in the first year. It’s an exciting moment after decades of unsuccessful attempts to find effective treatments for people living with obesity.”
Industry Influence and Access Issues
One critical point raised in the reviews is the heavy involvement of drug manufacturers in the studies examined. Many trials were funded by the companies that produce the medications, which raises concerns about potential conflicts of interest. The authors of the reviews called for more independent research to address these issues and to better understand the implications of using GLP-1 drugs on a broader scale.
Additionally, the authors highlighted social determinants of health, such as cost and insurance coverage, which can restrict access to these medications. Currently, the high prices of semaglutide and tirzepatide limit their availability, while liraglutide has become more accessible following the expiration of its patent, allowing for the introduction of generic versions. The patent for semaglutide is set to expire in 2026, which could further impact accessibility.
The reviews also noted that most trials were conducted in middle- and high-income countries, with underrepresentation of regions such as Africa, Central America, and Southeast Asia. Researchers underscored the importance of examining how these drugs perform across diverse populations, considering variations in body composition, diet, and health behaviors.
Co-lead researcher Eva Madrid from the Universidad de Valparaíso in Chile emphasized the need for further studies. “We need more data on the long-term effects and other outcomes related to cardiovascular health, particularly in lower-risk individuals,” she stated. “Weight regain after stopping treatment may affect the long-term sustainability of the observed benefits.”
The reviews ultimately recommend that future guidelines on GLP-1 receptor agonists for obesity treatment must be informed by longer-term studies that are independently funded. A clearer understanding of the benefits and risks will be essential for integrating these medications into long-term weight management strategies.
The findings from the Cochrane reviews will play a significant role in shaping the upcoming WHO guidelines on the use of GLP-1 receptor agonists, potentially influencing future public health policies concerning obesity treatment.