I always tried to review lectures the same night. This allowed me to essentially see material twice in one day. Then, on the weekends, I would review every single lecture in the order in which we got them on both Saturday and Sunday, typically starting at about 9am and stopping at around 5pm, leaving me plenty of time to do what I wanted to on weekends. So that is already around four times right there. Then, depending on how many weeks of material were on an exam, I would do the same with the next week's material, using Saturday and Sunday as review days. I would always review week 1 material as well, so that it stayed fresh. If we had Monday exams I would review every single lecture on both Saturday and Sunday. If we had a Friday exam, I usually tried to get through weeks 1 and 2 on Wednesday and Thursday. So, in summary, if 2 weeks of material was on the exam, I would see a single lecture roughly 6 times, maybe more, depending on how well I felt I knew it. It worked well for me, as I ended up top 10 in my class. I personally think that repetition is the best way to go, since med school is more volume than conceptual difficulty. Seeing it as many times as possible will make it easy to do well. It will also really cement it in your head for the long run. Good luck!