250ug of good acid is still a very high dose! 500ug is more like triple of a typical sane dose. milage may vary i guess but 300ug sent me out of this world

According to Erowid, a "light" dose is 25ug-75ug, a "standard" dose is 50ug-150ug, and a "heavy" dose is 400ug+.

I know a guy who took 1000ug. He told me he had side effects / visual glitches for about an entire week