yes weed grows in the nature but its all grass like any other plant but for the THC and THC doesnt KILL you it doesnt slowly eat your brain away and KILL the vessuls in your nose and shit, shrooms and pot was made to do the things to you with out hurtting you, but we made coke and all the other drugs, yes the stuff to make it came from the earth but when some chmicals are mixed it will kill you.
Neurotoxicity does not mean a drug literally 'eats away your brain'. Unlike methamphetamine, cocaine does not damage serotonin or dopamine neurons.
Cocaine is a naturally occurring substance. It is not synthetic, it too comes from the earth. Man does not make cocaine, man extracts cocaine and puts it in his lungs, nose or veins. Man could also simply chew the leaves of the coca plant which would numb the mouth and produce a mild stimulation. This method of use appears to be safe and is not addictive, but the law makes cocaine in its natural form illegal too.

Nicotine is a naturally occurring substance, it is one of the deadliest poisons known to man.