Hey OP it obviously isn't recommended but I do believe it is possible... depends on each individual though. Do you believe you're dedicated enough and have the ability to memorize/grasp material that you've never been exposed to before? I took the DAT after not having coursework for 5-6 years. I had completely forgotten everything and had to reteach myself every subject. I really had no choice but to learn it all on my own since my work schedule doesn't allow me to take coursework, including night classes. If I was you, I would just take the classes and make your life A LOT easier. You have plenty of time so do good in the classes, make friends with the professors for LOR's, and then nail the DAT. If you're stubborn.... Chad's videos supported with YouTube and lots of googling will allow you to get a good general chem foundation. For o-chem, I started out by going through organic chem as a second language I & II. I then did Chad's o-chem videos and after that I felt like I had a good foundation. You can get biology down by memorizing everything in Cliff's AP Biology 3rd Edition. Chad's videos for math are also good. Once you've done all of this, start DAT Destroyer, Math Destroyer, Feralis bio notes, and DAT Bootcamp for the PAT. Save the full length tests for your final month. Like I said though, take the classes and save yourself a ton of stress and the high chance that you'll have to retake