Recent research from Adelaide University has cast doubt on the safety of a key ingredient found in popular weight-loss pills. The study highlights that salcaprozate sodium (SNAC), used to enhance the absorption of semaglutide in oral formulations, may have adverse effects on gut health and other biological functions.
This work represents the first systematic in vivo examination of the impact of repeated SNAC exposure on gut microbiota and metabolic outcomes. Conducted over a 21-day period using animal models, the research suggests that, while it does not definitively demonstrate harm, SNAC’s biological effects may extend beyond merely facilitating the absorption of semaglutide.
Semaglutide, the active ingredient in weight-loss medications such as Wegovy, works differently when injected versus taken as a tablet. In its injectable form, it enters the bloodstream directly, whereas in oral form, it relies on SNAC to prevent degradation in the stomach and enable absorption. Without SNAC, oral semaglutide would be ineffective.
The approval of the Wegovy tablet by the United States in late 2023 has raised expectations for increased accessibility and affordability compared to injections. This shift may lead to a significant rise in daily SNAC exposure, especially given the alarming global obesity statistics. Approximately 890 million people, including 160 million children, are currently living with obesity, which amounts to one in eight individuals worldwide. In the United States, about 43% of those aged 15 and older are affected, while Australia ranks sixth among OECD countries with a rate of 31%, surpassing the OECD average of 25%.
Lead author and PhD candidate Amin Ariaee emphasizes the urgency of understanding the full biological impact of SNAC as oral obesity treatments become more prevalent. “Obesity is a complex, chronic disease with serious health consequences. These medicines are highly effective and are helping many people,” Ariaee explains. “But as oral versions become more widely used, we need to understand what repeated, long-term exposure to all ingredients in the pill means for the body – not just the active drug.”
The study’s findings indicate that while SNAC aids in the absorption of semaglutide, it may also contribute to shifts in potentially harmful gut bacteria, increased inflammatory markers, and depletion of proteins associated with cognitive impairment. These results point to a need for further investigation into the long-term effects of SNAC.
Senior Research Fellow Dr. Paul Joyce cautions against jumping to conclusions based on these early results from animal models. “Importantly, our findings do not prove that SNAC causes harm in humans,” he states. “However, they do show that the ingredient enabling these tablets to work may have adverse biological effects beyond drug absorption.”
As the use of these medications expands globally, the research underscores the importance of evaluating all components of weight-loss therapies. With many individuals relying on these treatments daily, understanding potential long-term health implications is crucial for both healthcare providers and patients alike.
