This post was inspired by a reply from a regular commenter (beograd) to an earlier post of mine about poison dart frogs.
I originally thought that this was going to be a light-hearted and humorous science piece but the more I read the less funny the whole topic became. In all seriousness, licking toads is a dangerous and inadvisable thing to do. It will very likely get you either sick or dead and in that order.
One of the toads in question that people think you can lick and get high is the cane toad (Latin name Rhinella marina). It is a large toad and can be found in Central and South America. The other is the Sonoran Desert Toad (Bufo alvarius) that can be found in southwest United States.
Toads in these species produce an alkaloid toxin called bufotoxin from their parotoid glands near the back of their heads. When the toad is stressed out it will release this toxin.
Basically, people 'milk' these toads by poking them or squeezing them and lick the excretion.
Bufotoxin can cause several serious and dangerous symptoms. If you ingest this toxin expect to experience vasoconstriction (narrowing of the blood vessels), respiratory distress, anxiety, panic, seizures, paralysis and possible death.
In short, licking a toad is the last way that you want to get high.
Of course, there is also the psychiatric effect of hallucinations which can be experienced when the skin of the toads is smoked. This is the putative effect that is chased after by users of the substance.
The substance excreted by the toad, bufotoxin contains a soup of chemicals, one of which is bufotenin (5-HO-DMT). The amounts vary from toad to toad and from species to species. Bufotenin is only a few atoms different in molecular structure to other naturally occurring psychedelic substances like psilocybin found in mushrooms and DMT which can be experienced in an Ayahusca ceremony.
The small change in chemical makeup though makes a large difference in the psychological experience. While DMT is reported to produce highly visual psychedelic experiences with both open eye and closed eye hallucinations, bufotenin experiences are said to be more cognitive and emotional. They are also very short experiences.
Sadly though licking a toad for a 'hit' won't work because the bufotenin compound is inactivated by the digestive system.
Closing Words
Licking toads is never ever a good idea and as I said earlier it is the last way you want to get a psychedelic experience. It must also be mentioned that in the United States bufotenin is classed as a Schedule I substance and will get you into some serious legal difficulties if caught.
Basically the risk of this activity is sickness and death and all for the low probability chance of having a weird psychological experience. Not a good bargain in my estimation.
Post Sources
https://en.wikipedia.org/wiki/Cane_toad
https://en.wikipedia.org/wiki/Bufotoxin
https://www.sciencedirect.com/topics/pharmacology-toxicology-and-pharmaceutical-science/bufotoxin
https://phys.org/news/2017-01-toad.html
http://www.universityobserver.ie/science/old-wives-tales-the-truth-behind-toad-licking/
https://io9.gizmodo.com/how-toad-licking-gets-you-high-and-then-kills-you-1642946043
https://erowid.org/archive/sonoran_desert_toad/LaLaw.htm
https://erowid.org/archive/sonoran_desert_toad/news.htm
https://oceanbreezerecovery.org/blog/licking-toads/