Sorry, I just got in from a long day. Yes, unethical and illegal practices are committed in States and other countries. It is extremely rare because of the oversight I described above and the massive fines and prison sentences a primary investigator and their licensed staff will suffer when caught. But there is always some idiot somewhere that will stray from the protocol. The motive is usually lack of motive, sloppiness and laziness in conducting the study properly, then, as a form of CYA, they will falsify results. These people are soon caught, lose their licenses, pay fines and often go to jail.
Experimenting on human biengs is serious business and skewing the result of say, a drug study, could harm a large population down the road. But most medical studies are spread to many labs throughout the country and even the world, so one lab falsifying results will show up as an anomaly in the grand scheme. This usually gets those results thrown out of the final configuration and the lab is investigated because all anomalies must be investigated—and that is how the culprits usually end up in the hands of the feds.
But it would be absolutely impossible to get a medical study design approved that is designed to harm people in any way. And if you can’t get it approved by the FDA and all the other official watchdogs out there, no licensed researcher will touch it with a ten foot pole, and if the study isn’t done by properly trained, licensed people who know how to correctly conduct a study, the results will never be taken seriously by anybody and will never make it into the all-important journals.
It’s a good, tough system, and except on very few occasions notable within the industry, it works very well.