I was worried about this as well. Here is a link to the requirements to get a license in the States. I called California's Medical Board and they told me you did not need any undergrad college credits or the MCAT taken (That was another rumor I heard). She said you just need to have completed the International Medical School also known as IMG (2 Years for CA). Other states are 3 years ... Check this link out for more info.

FSMB