The vast majority of CBD oils come in bottles measuring either 15 milliliters (mL), or 0.5 ounces; or 30 mL, or 1 ounce. However, CBD concentration is more important than bottle size. Concentration refers to the ratio of hemp oil solution (measured in mL) compared to the amount of CBD cannabinoid (measured in milligrams, or mg). A 15-mL bottle may contain 100 mg of CBD, 300 mg, 500 mg, or more. The higher the mg amount, the stronger the CBD oil will be. For this reason, the ‘mg’ measurement is also referred to as the oil’s strength; i.e., 400-mg oil might be called 400-strength oil.
In addition to acting on the brain, CBD influences many body processes. That’s due to the endocannabinoid system (ECS), which was discovered in the 1990s, after scientists started investigating why pot produces a high. Although much less well-known than the cardiovascular, reproductive, and respiratory systems, the ECS is critical. “The ECS helps us eat, sleep, relax, forget what we don’t need to remember, and protect our bodies from harm,” Marcu says. There are more ECS receptors in the brain than there are for opioids or serotonin, plus others in the intestines, liver, pancreas, ovaries, bone cells, and elsewhere.