Cannabinoid receptor agonists primarily target the CB1 receptor, which has several functions but just to be short, we will call CB1 the psychoactive cannabinoid receptor and CB2 the body receptor, so most these synthetics are aimed at high CB1 receptor agonism.

These synthetic cannabinoid agonists will often have NO chemical relation to any natural cannabinoid*, so it's not like this is simply THC or a natural cannabinoid core with an added "this" or subtracted "that", these are novel compounds which simply have high activity as the same receptor sites as THC with particular focus on CB1 receptors...

So, if your taking an aminoalkylindole class of cannabinoid receptor agonists that was recently devoloped and only has a minimal amount of human use, there's really no.way of knowing what it could do to you. Does the compound have toxic metabolites? Does it lead to physical damage long or short term? Can it cause death? We simply don't know yet.

I'm not saying these are "bad" compounds, I'm saying there are people with "bad" habits of marketing compounds before anything is known about them, you can't blame the compounds, and who knows, some of these compounds may turn out to be medically valuable, we just don't know.

* picture attached shows structural variations of cannabinoid receptor agonists.

Some of these cannabinoid receptor agonists are active in microgram dose...

-eg