Question regarding psilocin

[Memantine]

Some sources claim(Wikipedia) psilocin is highly selective for the 5-HT2B receptor, however:

A naturally occurring tryptamine that is rapidly metabolized to psilocin, which acts as an agonist of the 5-hydroxy tryptamine (5-HT) receptors 5-HT1A (Ki = 49 nM) and 5-HT2A, HT2B, and 5-HT2C (EC50s = 24, 58, and 30 nM, respectively);
https://www.caymanchem.com/pdfs/15696.pdf

So what is the order of the receptor action of psilocin?

5-HT2A>5-HT2C>5HT2B
or
5-HT2B>5HT2A>5HT2C

 

[.:Holy::Toast:.]

EC50 refers to the substrate concentration which will yield half of a maximal response for a given receptor, so that means the lower the EC50 value the more potent of an agonist the substrate is at a given receptor.
In order of increasing activity it would be 5-HT2B<5-HT2C<5-HT2A.
This coincides with the general consensus that psychedelics exert their primary effect through 5-HT2A agonism.
However there is literature which states that psilocin does exhibit strong 5-HT2B agonism, however I'm not sure where the discrepancy in research originated or which data I trust more.
It seems to me that psilocin would not be near as strong as a 5-HT2B agonist as phenethylamine psychedelics since 5-HT2B agonists tend to cause vasoconstriction and have been associated with cardiac toxicity, and psilocin is generally not associated with either.

 

[serotonin2A]

Psilocin is nonselective for 5-HT2 subtypes. The EC50 values you listed are effectively identical.

To be "selective" there really needs to be at least a 10-fold difference in affinity. And that is the bare minimum to say that a ligand shows some evidence of selectivity. For a ligand to be selective, you usually want to see at least 100 fold difference.