Insulin dysregulation is one of the leading risk factors for laminitis. | iStockInsulin dysregulation (ID) is one of the leading risk factors for laminitis, and some horses still struggle to manage insulin levels even with proper feeding and exercise management. Caroline Loos, PhD, equine nutritionist and head of research at Cavalor, and fellow researchers completed a study while she was a postdoctoral student at the University of Kentucky, in Lexington, to evaluate the impact of essential-oil-derived bioactive molecules on insulin dynamics and identify potential biomarkers or metabolic signatures associated with essential oil (EO) supplementation. Loos presented the teams results at the 2025 American Association of Equine Practitioners Convention, held Dec. 6-10, in Denver, Colorado.Inside the Study: Examining 20 ID HorsesThe researchers studied 20 mature horses diagnosed with ID, none of which had active laminitis. For six weeks, they gave 10 horses a commercial oral supplement containing a proprietary blend of 12 different essential oils including Eucalyptus globulus (Tasmanian blue gum tree), Allium sativum (garlic), and Betula alba (silver birch plant) daily, and 10 received a placebo oil. To allow accurate assessment of the supplements effects, they did not make any other dietary changes during the study. Horses remained on the same diet and management used for more than a year prior. They were housed on dry lots with free-choice grass hay, salt, and mineral blocks, and fed concentrate twice daily.Before and after the sixweek period, researchers ran the standard combined glucoseinsulin tolerance test (CGIT) for insulin resistance and oral sugar test (OST) for hyperinsulimia. They also analyzed hundreds of metabolites in the horses blood to look for deeper metabolic shifts.What Researchers FoundEffects of EO on insulin dynamics were strongest in the subset of horses with more severe initial ID, Loos said. In these horses the essentialoil supplement:lowered insulin levels during the CGITimproved insulin sensitivity, meaning their bodies used insulin more effectivelyreduced the insulin spike following an OSTThe supplement did not change how horses absorbed glucose. Rather, it changed how their bodies responded to it.Loos also looked at the results on a biochemical level. The essential oils led to widespread changes in metabolism, altering more than 700 different blood metabolites, she said. These shifts occurred across key metabolic pathways related to mitochondrial function, methylation, amino-acid metabolism, bile-acid signaling, and antioxidant defense, suggesting a broad impact on metabolic health.Take-Home MessageIn this study Loos and her team showed EO might help improve insulin sensitivity and moderate insulin spikes in severely ID horses. While more research is necessary, Loos said essentialoil supplementation could potentially be another multitargeted approach for s ID horses.Editors note: The author(s) declared this project was supported in part by Versele-Laga (Deinze, Belgium) and that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.