Its not a direct translation, but that dosage would be somewhere in the range of several hundred milligrams for an adult human. CBD has a very low bioavailability, something between 6 and 15 percent, which varies between people, says Blessing. Because ingested CBD is so inefficient at actually getting to the brain to stimulate CB1 and other receptors, the doses shown to be effective have to be very high. Theres no evidence that doses below 300 mg of CBD have any effect in any psychiatric measure, says Blessing. The limited studies out there indicate that CBD has, in its various interactions with the brain and immune system, some anti-inflammatory and anti-anxiety effects.