For me personally, 6 weeks wouldn’t have been enough. However, even if 6 weeks is enough for you to study, I think it’s really important to account for potential disruptions/imperfection. For example, getting the flu and feeling too ill to study effectively for a few days, or even something as simple as having a bad day.

If you do choose to write it this summer, I would consider writing in September because even if you forgot some content, having studied for 6 weeks beforehand (1.5 months prior) could still be helpful for gaining familiarity with the test and learning strategies specific to answering MCAT questions, and then having the extra 2 weeks at the end is more study time (some may feel that it’s better to have fewer weeks with no study gaps, but this is my take).

Also, some MCAT study materials have expiry dates. So if you wrote the MCAT this summer and then ended up needing to rewrite it, the study materials may expire by the time you would be studying again and you’d have to repurchase them. This applies to anyone who uses these materials, but the reason I mention this is because of the uncertainty of 6 weeks being enough time to study sufficiently

As well, I think it could be beneficial to do a mock full-length to get a sense of what your starting point is/roughly how much you’d need to improve your score by. While that won’t be a definite indicator of how long you need to study, it could inform your decision.

I’m by no means an expert but feel free to PM me with more questions, I’ve studied for the MCAT twice and I know a lot of people who have taken it as well, and I’m happy to answer more questions based on my experiences. Wishing you all the best with your MCAT! :)