Hey,
For anyone interested in pharmacology of our beloved entheogens, take a good look at the article
Psychedelics and the Human Receptorome! It really challenges our way to view how these substances work.
There are many surprises, such as that ibogaine is the only substance to show highest affinity for a sigma-receptor, DMT has strong interaction with a dopamine-receptor, and that MDMA has the strongest affinity for a imidazoline receptor. You should really take a long, good look if you are into this stuff - the article is amazing!