The present investigation was conducted with an objective to validate the effect of the plant Azadirachta indica (neem) in human blood cells in a normoglycemic medium. This hypoglycemic effect had been attributed by the communities to this plant. In this study, aqueous extract of the plant was used in a concentration of 6.4% m/v and from this, following doses were prepared: 0.01 mg; 0.05 mg (low doses); 0.1 mg; 0.175 mg (medium doses); 0.7 mg and 1.4 mg (high doses); also it was used insulin Humulin R ® in different concentrations (0.1, 1, 10 nM) in order to compare both effects in a normoglycemic medium with human blood cells. The results demonstrated a hypoglycemic effect when the levels of glucose concentration went down in the normoglycemic medium in relation to the control. There was a significant effect (p<0.001) for the high doses group. These findings validate the hypoglycemic effect of this plant attributed by the communities.