Buying online is less reliable still because there’s no regulation or standardization. What you see on the label may not be what you are getting. A 2017 study in JAMA found that of the 84 CBD products researchers bought online, 43 percent had more CBD than indicated, while 26 percent had less, and some had unexpected THC.“There’s a 75 percent chance of getting a product where the CBD is mislabeled,” says Marcu, one of the study’s coauthors.
Then there is the matter of which part of the plant is used. THC tends to be more concentrated in the leaves of the plant, while CBD in its stem and seeds. It should be noted that these aspects are relative. Some degree of agreement exists that for the purest CBD, the stalk of a hemp plant (varieties of cannabis generally grown for fiber manufacturing, low in THC), or much less often the seeds. Taking into account the fact that CBD supplements are usually in an oil form, one may fathom the origins of the nearly ubiquitous hemp oil dietary supplements.