to add a little context; ~100ug is a solid single dose ~75ug is a light dose ~25ug is just a bit above threshold - this is generally the upper range for a microdose. ~10-15ug are the absolute minimum for any effect at all.

That said, the short-term tolerance curve is incredibly steep. What ends up happening with a lot of folks who microdose for extended periods is that they'll increase the 'micro' until they make a rounding error and then all of a sudden your desk is melting and your mouse has a half-minute delay. Best practices are to stagger days and take occasional three-to-four day long breaks.

50-150 micrograms according to Erowid. https://erowid.org/chemicals/lsd/lsd_dose.shtml

~100μg.

roughly 100-300 mcg