I plan to do a DIY post bacc starting this summer but was not sure if I should retake the classes I got a C or C+ in. Unfortunately, most of the science classes I took I got a C/C+ in. I've been told by premed advisors that I should retake all the courses I have gotten any sort of C in. I have also been told by medical students to only retake the courses I got a C- in, then from there take new upper division biology classes. My overall goal is to increase my sGPA to a 3.0.