You always need biology, chemistry, organic chemistry, physics, and math to go to a US medical school. So as an anthro major, you'd need to take these classes as electives... which would actually probably make it very difficult.
Another option is to finish your not-so-useful major, whatever it is, and then enroll in a postbaccalaureate program designed to give you the pre-med courses you need.
Best of luck!
Yasemin recommends the following next steps:
Typical medical school prerequisites include:
Biology: Lecture – 4 semesters; Lab – 1 semester
General Chemistry: Lecture – 2 semesters; Lab – 1 semester
Organic Chemistry: Lecture – 2 semesters; Lab – 1 semester
Biochemistry: Lecture – 1 semester
General Physics: Lecture – 2 semesters; Lab – 1 semester
Math: Statistics – 1 semester
English: Rhetoric (Composition) and Literature – 2 semesters