There are a few ways to get CBD into your body. The most common, used in both clinical trials and consumer products, is via an oil in which CBD, which is naturally soluble in fat, has been dissolved. CBD oil can be taken orally, inhaled as a vape, or applied topically. Topical application is supposed to work sort of the way Icy Hot does, affecting a local muscle area specifically to reduce aches and pains, but the other methods produce full-brain and -body effects.
Yes, it does matter. The flower-tops and leaves of some industrial hemp strains may be a viable source of CBD (legal issues notwithstanding), but hemp is by no means an optimal source of cannabidiol. Industrial hemp typically contains far less cannabidiol than CBD-rich cannabis. Huge amounts of industrial hemp are required to extract a small amount of CBD, thereby raising the risk of toxic contaminants because hemp is a “bio-accumulator” that draws heavy metals from the soil.
Cannabidiol, or CBD for short, is a natural phyto-cannabinoid (or plant-based chemical compound) found in cannabis plants, including hemp and marijuana. Unlike other cannabinoids — namely tetrahydrocannabinol, or THC — CBD does not produce any psychoactive effects, and will actually counteract these effects to a degree. CBD will induce feelings of sleepiness; for this reason, it can be an effective soporific for people who struggle to fall and/or remain asleep due to insomnia and other sleep disorders.