It's true. Marijuana is actually one of the very few substances with no known LD50. Technically there is hypothesized to be one, but it is so high that it would be literally impossible to ingest that much (you'd suffocate from lack of oxygen first, and that's assuming you somehow weren't incapacitated from being so high that you were able to keep smoking. So medically, that's considered equivalent to "no lethal dose exists".
It starts to get really complicated once you involve edibles, though - you can't just straight up eat plant matter and have it take effect as if you'd eaten a brownie, even though the dosage would technically be much, much higher if you straight up ate a bud.
I'm no scientist nor a baker so I don't know the details behind it, but as far as I know the THC needs something to bind to before it's digestible, usually a fat - probably why cannabutter is the most common way of getting it into edibles.
And that doesn't even account for the CBD which I have zero idea about with regards to edibles.
THC is far from the only compound in cannabis. There are hundreds of them, with virtually all of them having had far less study done on them than THC has.
If a human were to die of cannabis inhalation or ingestion, it's not clear which of the hundreds of compounds in cannabis would be the one most responsible for the fatality. It's quite possible that it wouldn't be THC.
It's also that THC isn't very psychoactive until it's been decarboxylated. The process of heating it within a particular temperature does this (e.g smoking, vaping, baking)
> If you eat it you can ingest the dosage confirmed to kill dogs
You would almost certainly vomit long before you hit that threshold.
If you also took an anticonvulsant and just straight-up downed raw plant material, I suppose it's possible... but at that point, we're stretching the meaning of "lethal dose".
Don't know much about the extracts, but I know in legal states concentrates of various types have been developed and people are getting progressively better at concentrating them further.
Is it possible we could see an overdose at some point once physical volume becomes much less of a factor?
http://www.mindthesciencegap.org/2013/03/25/how-safe-is-mari...