Earlier quoted context omitted.
> All psychedelics are at least as safe as alcohol This is false. LSD and mushrooms are arguably as safe as or safer than alcohol. However... There are hundreds other psychedelic compounds in existence, and some can acutely cause death, some even at doses close to recreational levels. Phenethylamines can all be deadly, and nboms cause extremely dangerous vasoconstriction. Some significantly lower seizure threshold. I…
Just practically, 'psychedelics' can be broadly or narrowly defined. Hunger and thirst can induce hallucinations, for example. A wide variety of toxic and pharmacologically active compounds have similar side-effects. Hence, a narrow definition makes more sense, as compounds binding to the 5-HT2A serotonin receptor, which is a much smaller list: https://pubmed.ncbi.nlm.nih.gov/33740877/
Chemicals like https://en.wikipedia.org/wiki/25I-NBOMe#Toxicity are among the most potent agonists of the 5-HT2A receptor, and are also extremely dangerous due to potency and their vasoconstrictive and cardiovascular effects.
(There are horrifying stories of people being sold "acid" and then their lips turn blue from vasoconstriction and subsequently need hospital intervention - see: https://www.erowid.org/experiences/subs/exp_25INBOMe_Health_...)
A significant number of the deaths the nbom family has caused can probably be attributed to the difficulties of clandestine dosing in microgram amounts, but I think they may still be more dangerous than alcohol even when dosed accurately. It's certainly more dangerous for naive users without the proper equipment to measure and handle it.