Study: Metformin Doesn’t Help Insulin Resistance in Horses

Metformin, a drug often prescribed to human patients with insulin resistance, apparently doesn’t help horses with the same problem. In humans, metformin enhances the body’s response to insulin, decreases blood glucose, and promotes weight loss. Trials conducted in Australia with horses failed to show similar results. When horses were given metformin, no significant changes in body weight, blood glucose level, or insulin utilization were found, and these results were consistent with earlier studies.

Glenys Noble, Ph.D., director of the research, said many factors could account for the difference in medication results in horses and humans, with varied digestive physiology probably playing an important role. She said that management of insulin-resistant horses should be built around regular exercise and year-round moderation of forage intake rather than free-choice grazing.