Choosing a Training Path:
MD/PhD
These are traditional programs that integrate research and medical training without sacrificing the quality of either. In most cases, the programs demand defined times when only one of the programs is intensely studied. 
The program usually takes 7 to 8 years to complete which means that your PhD training needs to be focused. There is a shorter time between completion of the PhD and initiation of independent research as a faculty member when compared to obtaining a PhD before medical school. This program however needs some postdoctoral training at the end of the MD/resident training before embarking on an independent faculty position. These MD/PhD programs each have a limited enrollment and often provide generous financial support during the full program, for both the PhD and the MD components.