Moringa oleifera (MO) is used for a number of therapeutic purposes. This raises the question of safety and possible toxicity. The objective of the study was to ascertain the safety and possible metabolic toxicity in comparison with metformin, a known drug associated with acidosis. Animals confirmed with diabetes were grouped into 2 groups. The control group only received oral dose of PBS while the test group was treated with ethanolic extract of MO orally twice daily for 5-6 days. Data showed that the extract significantly lowered glucose level to normal values and did not cause any significant cytotoxicity compared to the control group (P=0.0698); there was no gain in weight between the MO treated and the control groups (P>0.8115). However, data showed that treatment with an ethanolic extract of MO caused a decrease in bicarbonate (P<0.0001), and more than twofold increase in anion gap (P<0.0001); metformin treatment also decreased bicarbonate (P<0.0001) and resulted in a threefold increase in anion gap (P<0.0001). Conclusively, these data show that while MO appears to have antidiabetic and noncytotoxic properties, it is associated with statistically significant anion gap acidosis in alloxan induced type 2 diabetic rats.