Roughly one drop per square [also called a Tab of Acid ].

But there you go.

1. How concentrated is the liquid acid?

2. How much was put onto the little square?

3. How long ago was this all made?

4. How accurate was the (illegal) chemist who made the LSD in the first place?

I will say that one TINY drop of acid is enough to make you trip for 24 hours. And on the square of cardboard the LSD is not necessarily evenly distributed, so a corner of the square can be where 90% of the active ingredient is. The effects vary wildly: Some LSD is quite visual, some has almost no visuals but plenty of mind-messing.

All of these factors combine to mean it is EXTREMELY difficult for anyone to estimate what a low dose is. Especially someone experimenting for the first few times.

Please research carefully, and if you still decide to experiment, ensure you are in a safe environment with understanding people.

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I've read that if you take an extremely low dose it's non-psychotic but still has a number of positive cognitive effects

Please read my comment item?id=654676 carefully.

Non-psychotic depends a lot on who-you-are: not the dose. I don't know you, and further I don't know anyone else reading this in the future.

Depending on the type of person you are, you could flip out badly on any dose.

LSD can unleash things inside you. People who you love... you may see them as snakes/undead. You may see your face melt off. More importantly you will feel horrified when this happens. It takes a lot of training to overcome the horror (if it happens).

I am not going to give the green light for experimentation with something that has such power when the downsides are so grim.

All my friends who flipped out were sold on the Lucy in the Sky with Diamonds version of events. But the variability of the ingredients, their situation and their personality sometimes made it awful.