The present study evaluated the effects of seven days, twice-daily administration of hot water infusion of dried Moringa oleifera leaves on the steady state plasma concentrations of Metformin, one of the most widely used OHAs using T2DM patients who have been on Metformin for a period of not less than three months. The included patients had also been on Moringa supplementation but had terminated the use of Moringa at least a month to the start of the study.