Yes, this only say no proper check has been done and enforced. There's a documentary called Leaf of Faith that shows that a little. People ~manufacture too many things without any testing and sell it. Don't buy that you could get anything from salmonella to weird chemicals.. noone knows. Some do testing but it's rare. About the safety of the compounds in the leaf, some researchers say it taps in the same receptors but with less activation factor in cells (maybe the reason behind the lack of addiction).
[0] https://www.fda.gov/newsevents/publichealthfocus/ucm584952.h...