B2 was working great for me all last week, but was leaving me extremely tired. I've never been so clear minded, and un-agitated in all my life! Not to mention, my vision was much clearer. Switched to FMN in hopes of alleviating the fatigue. It went away for a couple of days, but now, I'm noticing the agitation is coming back. I've been riding it out to see if it's an external factor, but it's getting worse, and pretty much back to where I started. Vision has gotten a little fuzzy again too. Has anyone else done worse on FMN (or R5P) than on normal B2?