I decided to try some methylfolate just to see what would happen. Used the LifeExtension brand.
I took one pill (1 mg). The effects consisted of a straining sensation in my eye muscles, a feeling of effortless hyperfocus, automatic effortless multitasking, and very bad ability to stay on track.
Last fall I took a B-vitamin complex with l-methylfolate and after the first dose I got insomnia and felt irritated at the world. It gave me energy and fired my brain up but over the course of weeks of trying it on/off my insomnia became extreme and the whole world irritated me, I just wanted to be alone in a dark room and not talk to anyone. To this day I still suffer insomnia if I take folate rich foods around dinner time or late night. I never took B vitamin supplements again.