Hypoglycemia effect Opuntia streptacantha which occur in diabetic has not been found in healthy subjects. To find out if this effect appears also in healthy individuals if they are hyperglycemic, two tests were performed to 7 healthy volunteers. In both tests 500 ml of 20% dextrose were infused in two hours, 500 g of O. streptacantha were given orally before one test, and 400 ml of water as control were given before the other one. Serum glucose was measured every 30 minutes during three hours. Glucose rising was significantly (P less than 0.025) lower with Opuntia than in control test at 90 and 120 minutes (143 +/- 58 vs 193 +/- 9 and 135 +/- 25 vs 163 +/- 13 mg/dl respectively). Area under curve of glucose was also smaller in Opuntia than in control test (P less than 0.05). Hypoglycemic effect of O. streptacantha also occur in healthy subjects in hyperglycemia is present.