[TheSpiceIsLife]

The liver can make some things more water soluble to be excreted via the kidneys, or more fat soluble to be excreted via the gallbladder > stomach > bowel.

I haven’t looked in to it, but I’d hazard a guess that, if this story is true, some of the toxins are excreted via the second route mentioned above, thereby rendering the urine less toxic.

Everyone I’ve known who has consumed amanita muscaria has said something to the effect of “I won’t do that again”. Two mates ended up in hospital for a bit.

Not an extreme sport I’d recommend.

[fleetingmoments]

Amanita Muscaria can be consumed safely (with no tripping) by parboiling for 10 minutes and discarding the water. Repeat this process at least twice. It's got a lovely nutty flavour.

[hinkley]

Alkaloids. I can't remember if the heat denatures them or they are solluble, I think it's a mix of both.

There's a theory out there that 'bitter tasters' are an evolutionary adaptation by our Eastern European forebears who lived in an area where alkaloid levels were high in soils. If you avoided alkaloid-embittered foods your liver lasted longer, and so your genes were better represented.

[Matticus_Rex]

Don't know why you're being downvoted -- this is accurate.

[meschi]

https://en.wikipedia.org/wiki/Amanita_muscaria#Toxicity

https://en.wikipedia.org/wiki/Ibotenic_acid

Amanita Muscaria contains muscimol and ibotenic acid. Ibotenic acid is neurotoxic and a prodrug to muscimol, which has the desired psychoactive effect.