Hi there! Great question.
I highly recommend taking at least one full-length practice test before finishing your content review, and often recommend that students take two. A lot of students try doing 100% of their content review first, usually either because 1) they don't want to "waste" any exams or 2) they know they won't score as highly on an exam if they haven't seen all the content, and the idea of that makes them nervous. From what I've seen, though, it's generally a fairly significant mistake to try to complete all of your content review before starting to take any practice exams. Here are a few reasons for this:
- If you complete all of your content review first, you'll be going a significant amount of time without ever seeing/feeling what the MCAT looks like. This tends to make students study "in the wrong way" - often hyperfocusing on learning/memorizing/retaining every detail they read, and making content review take forever. Don't get me wrong - it's good to know the details! But taking at least one FL can show you the ways in which the MCAT really is all about overarching concepts and foundational content rather than tiny details.
- It generally takes several FLs for a student to get into a groove. (This is why students often take a diagnostic, study tons of content for a month, and then take another test and find that their score didn't improve.) Your amount of content knowledge does not directly correlate with how you perform - instead, I'd say that your experience with the exam, question style, etc. is what correlates with success. So students who do all their content review first and then start taking FLs often find that they score well below they expect. If you can handle this, that's fine! Your score will go up as you take more exams. But it can tend to be a bit demoralizing.
- Taking FLs early helps build endurance, which of course is an essential skill.
- Some students actually find it helpful to take at least one FL where they don't know all the content, precisely because they don't yet know all the content. I know this sounds really weird, but taking an FL where you confidently know you won't be familiar with everything tends to really promote a reasoning-heavy mindset. Let's say you haven't covered acids and bases yet, and you see a passage about the acid-base chemistry of the digestive tract. You're much more likely to look to the passage and really think the questions through, because that's the only way you're going to get the answer. Students who do all their content review, on the other hand, tend to really freak out when they inevitably see unfamiliar passages, because they "feel like they should know everything already."
- Finally, planning to do all your content review first reflects the incorrect idea that students can ever be done with content review. Even if you cover 100% of the material in the TPR books, you're likely to forget some as you go, or miss questions due to the material being presented in a different way. The best technique for almost all students I've seen is to combine content review with at least some passage practice whenever possible, and regularly sprinkle in FLs. This way, you see how content can be tested - not just presented in a prep book - from the very beginning.
(Of course, if you do end up taking any FLs before content review is done, don't stress out about the score. But also don't think of it as "wasting" an exam - it absolutely isn't! It's a way to get accustomed to the MCAT early, which has a considerable amount of value.)
Good luck 🙂
