Ok, I (22M) was on Ritalin IR for 6-7 months. Went from 10mgs a day to 60mgs a day. It worked great, i had lots of focus and i felt great. On month 7 I stopped because I would get severe tachycardia and it would make me have anxiety.

Went to Folacin IR 10mg 2x a day for a month and it worked ok in terms of focus but really just gave me energy. I trialed vyvanse for 20 days, it didnt work out so i went back to focalin IR

Now when i take focalin (same generic MFM as before) it gives me brain fog, and it only lasts for 2 hours.

Why does it feel different this time??? Is it due to the bio accumulation of it in my system?

Does anyone have this type of experience?