Homeopathy

not just the US.

everywhere has to do trials.

what you're describing is the patent process. whereby once a drug, or more specifically an active ingredient and its method of manufacture is described and patented, that method cannot then be used by other parties. this allows the inventor time to reap the benefits. however, getting from active ingredient to drug in human ~ 15ish years. giving the drug company ~10 to go from first stage clinical trial to final drug. but in reality that's only probably 5. which. is 5 years to reap back all their costs, and pay dividends to shareholders

Thanks for that you described it a hell of a lot better than I.