They worked great for me. I ended up listening to all the cd's about 3 times each cd (theres 12). I listened to them every nite. I worked in the summer from 8-3. Then I studied from 4:30 to 10 . Went home and ate dinner. Then walked the dog and went to bed. While in bed I listened to the cd;s for about a half an hour until I Passed out from complete exhaustion. But I credit the cd's with giving be the drive to keep doing it everyday. They helped me remember some hard concepts and gave me great pnuemonics for certain bio and orgo areas .Id say buy them and also buy the exam krackers books they kicked ass helped me go from a 20 to a 27