What GCSE and A level grades would I need to get into cambridge or Oxford university to do Medical Science?

this isn't exact but my friends parents went to oxford and she said probably about 7 A*s of any gcse's and then 3 A*'s at a level of all sciences and that wouldn't even mean you'd get in, as so many people apply, i've heard even your social background is a part of whether you get in or not.