The chemical formula of CBD was proposed from a method for isolating it from wild hemp. Its structure and stereochemistry were determined in 1963. Plant breeding
Selective breeding of cannabis plants has expanded and diversified as commercial and therapeutic markets develop. Some growers in the US succeeded in lowering the proportion of CBD-to-THC to accommodate customers who preferred varietals that were more mind-altering due to the higher THC and lower CBD content. In the US, hemp is classified by the federal government as cannabis containing no more than 0.3% THC by dry weight. This classification was established in the 2018 Farm Bill and was refined to include hemp-sourced extracts, cannabinoids, and derivatives in the definition of hemp. Society and culture
Foods and beverages
Food and beverage products containing cannabidiol were widely marketed in the United States as early as 2017. Hemp seed ingredients which do not naturally contain THC or CBD (but which may be contaminated with trace amounts on the outside during harvesting) were declared by the US Food and Drug Administration (FDA) as Generally recognized as safe (GRAS) in December 2018. CBD itself has not been declared GRAS, and under US federal law is illegal to sell as a food, dietary supplement, or animal feed. State laws vary considerably as non-medical cannabis and derived products have been legalized in some jurisdictions in the 2010s.
A recent study using X-ray crystallography showed that CBD binds inside the sodium channel pore at a novel site at the interface of the fenestrations and the central hydrophobic cavity of the channel. Binding at this site blocks the transmembrane-spanning sodium ion translocation pathway, providing a molecular mechanism for channel inhibition, which could contribute to a reduced excitability. A small clinical trial reported that CBD partially inhibited the CYP2C-catalyzed hydroxylation of THC to 11-OH-THC. Little is known about potential drug interactions, but CBD mediates a decrease in clobazam metabolism. Veterinary medicine
Research
The number of research projects and scientific publications on cannabidiol and other cannabinoids in pets has surged in the late 2010s. As of December 2020, there are no hemp-derived, cannabinoid-rich registered veterinary medicinal products in any of the major regions (see Legal status across countries). In the US and other territories there are, however, numerous veterinary nutraceutical products available OTC. The lack of clarity in the regulations governing veterinary hemp food supplements allows for products of questionable quality to flood the market, which may pose a risk to the wellbeing of pets and owners. To understand better the benefits of CBD and associated compounds for the quality of life of animals, companies specialized in CBD products for animals have been funding research projects. Canine osteoarthritis
CBDs ability to help regulate the endocannabinoid system and reduce the release of excitatory neurotransmitters could result in a retrograde inhibitory signal that lessens chronic pain responses.