>>11083088All medicines work fundamentally the same, they are "venoms" in the sense that they block something. Think cell processes like this, like a giant conveyor belt with many machines giving form to a cubed block, if at some point of the production line you introduce a sphere the chain stops because the machine cannot work on spheres nor can it take out the malformed piece.
Painkillers block out either the synthesis of pain signals or the receptors of those signals or antibiotics are simply venoms for things that the bacteria has and you don't and so it can't hurt you(although you have mitochondria which does share things with bacteria, that's why people feel bad when they take antibiotics).
Herbal medicines are studied way too well, in fact everything that is european and has been used for centuries has been studied to death and every single component has been determined and categorized simply because they were accesible for scientists, and it's still an open field with people investigating plant in exotic places to see if they catch any weird compound that can get them a nobel or at least a mention in a paper.
What happens is that herbal medicines are not really used in conventional medicine simply because we know them so well that we know exactly what we want from them and how we want to deliver them to the body in the concentrations that we want.