Citation? And there's a fair bit of safety research on GMOs in humans... (See comment in other chain) Well yeah, that's just called herbal medicine; it's less controlled dosage and more potential contaminants, but still viable for plenty of people. The trouble is when you start getting into with proof of patient improvement for more off-the-road treatments. There is some value to the placebo effect, but when you're comparing that to drugs not found in nature, you're usually worse off (Not that every illness deserves a drug, but for those that do). Besides, pretty much every drug, natural or synthetic has side-effects, the point is to characterize them and prescribe them in cases where appropriate (Not that that is always the case, either =/).What's wrong with naturally occurring plants? GMOs have already been linked to Colony Collapse Disorder in Bees. Since most European nations have banned them, they've noticed their bee populations come back.
And what's wrong with "alternative medicine?" If natural medicines were the original medicine, aren't pills made to cure symptoms instead of causes made in a laboratory with extreme side effects the alternative?