Abscisic acid (ABA) is a plant hormone also found in animals. It stimulates insulin release from pancreatic cells and increases in normal human subjects, but not in diabetic patients, after a glucose load for an oral glucose tolerance test (OGTT) ^[1]. In this study, human volunteers underwent an OGTT or had standard meals, with or without a fruit extract, yielding an ABA dose of 0.85 or 0.5ug/kg, respectively. Lab measurements were conducted at different time points. Oral ABA significantly lowered glycemia and insulinemia in humans. Thus, the effect does not depend on an increased insulin release. Low dose ABA may be proposed as an adjunct to improving glucose tolerance in diabetic patients who are deficient in or resistant to insulin.