Prevalence of poor metabolizers of bupropion is 20.56% in North Indian population residing in the National Capital Territory. (Healthy volunteers (n=170) from the metropolitan area encompassing the entire national capital territory (Delhi) and urban areas of neighboring states of Haryana, Uttar Pradesh and Rajasthan). Significant difference was observed between the mean ratio of metabolite/drug of rapid metabolizers (Mean = 0.59) and poor metabolizers (Mean = 0.26) with P<0.0001 using student t-test (Varshney, 2012).