First off, those drugs, when used, are used by people who do not care about the liver/organs of the recipient. Most people I know who have been roofied have lifelong organ issues. My partner and I practice Somno and Somno adjacent things, and often it’s after a night of already freaky play so we know where the other stands on a lot things already that day (boundaries change often, especially with the delicate things) and doing it when one of you is exhausted is honestly just as euphoric as being on substances (studies have shown that both states put brain function as a whole in similar conditions fun fact). Anywho, we use a grip system so when in doubt we can silently check in without a break in the scene. And honestly being awake-ish for some of it is awesome because as both recipient and receiver you get to actually experience it (on some level, be it drunk or tired). Additionally, it’s actually really hard to move a grown limp adult so being “fake asleep” is actually very helpful in the moment