“Knowing the source of the hemp used in making a CBD product is important because it gives you insight into [a variety of components],” says Vanessa Niles, M.D., a medical cannabis expert at Heally, a telehealth platform for alternative medicine based in New York. Source information can indicate whether the hemp is sustainably farmed; organic; contains pesticides, heavy metals, or other fertilizer chemicals; and has been tested by a third-party laboratory.

“Harmful additives can undermine the quality and safety of CBD oil,” says Dr. Niles. For instance, hemp plants treated with nonorganic chemicals can create a bitter taste. Even worse, you may end up ingesting those chemicals in the final product in harmful amounts, which can result in serious health conditions, such as kidney damage and cancer.

Variability in quality and lack of regulation in the CBD market ultimately affect how consumers feel about the cannabinoid. In fact, 21% of U.S. adults think CBD should still be deemed illegal and 19% remain on the fence about this issue, according to a recent Forbes Health survey of 2,000 U.S. adults conducted by OnePoll.