Certifications Herbs
Here’s some certifications or registrations to look for on supplements & herbs:
USP may be best because they buy products in stores & test 6x a year
http://www.usp.org/usp-verification-services/usp-verified-dietary-supplements/verified-supplements/participating-companies
GMP includes testing for professional sports banned lists
NSF
UL
Consumerlab has testing available to review by prescription
Pharmaceutical grade is a higher level of purity & review in manufacturing as well.
US manufacturing & processing may have better supervision even of pharmaceutical grade
https://www.consumerreports.org/supplements/how-to-choose-supplements-wisely