are not the same as the scientist etc. that bring a drug to market. In fact, their goals are very different. It is like the scientists who work at the EPA - they care, they are careful but it is the people at the top who maintain the power. Research can be destroyed, or hidden when it does not conform to financial goals. People who speak out about the dangers of a certain drug have found their careers and life in general destroyed, and that has happened - in many walks of like.
The L-tryptophan debacle was a mistake in manufacturing in Japan and that was discovered early on. Other manufacturers were making a safe product but the ban on all L-tryptophan lasted years. It is a competitor for serotonin re-uptake drugs. It was suspected that was the reason for the ban to last so long.
I am well aware of digitalis as I take digoxin, a drug that was first formulated in the late 1800s. When I started taking it, the cost was low. One company is now supposedly the only manufacturer which is the excuse for the drastic increase in cost. There will come a day when I will no longer be able to afford it, then it won't be saving my life anymore.
The use of plants for medicinal purposes is more sophisticated than folk medicine now. There are several publications that people can read to learn about what has been tested and the results.
I am not suggesting that people are not committed to their work in the pharmaceutical field, but there are problems. I will maintain my cynicism especially when those products are not available to everyone, even the most needy and sick.