Hey @Alecie good questions!

I have a couple of articles about the long term ramifications - to be concise, it depends on the Nootropic. Some are very safe, like Piracetam which underwent 20 year population studies. With others there's some risks. However, I've been doing them for 7 years now and have experienced almost no negatives from them.

In this section of my site I meta analyze over 50 of them and frankly discuss risks and downsides http://www.limitlessmindset.com/resources/nootropic-ingredients

I've gone off them for as much as 6 months.

I've never tried microdosing LSD. I'm kind of a stickler for legality. Hopefully they make it legal at some point.