Bioavailability of CBD: Comparing Methods of CBD Administration

Not all CBD consumed orally actually reaches the endocannabinoid system.

When consumed orally, cannabidiol (CBD) is processed by the liver and other digestive organs. Only a percentage of the CBD consumed passes through these organs and makes it into the bloodstream, so it can be used by the endocannabinoid system. Any excess CBD is stored in fat cells. If enough CBD is consumed, CBD can remain in the fat cells for days, releasing gradually for use by the endocannabinoid system. So, although oral consumption doesn’t provide the highest availability, if you consume enough consistently, oral consumption is a very effective way to treat certain chronic conditions.

The “first-pass effect” is the term used to describe the metabolism of chemical compounds in the liver and other digestive processes, which causes a significant portion of medicine consumed orally, to be broken down into unusable components and limiting the amount of compound which is bioavailable to cells in the body.

If consumed orally and at significant enough levels, CBD tends to be absorbed by the fatty cells, and can provide benefit for chronic conditions throughout the day. A study by Zhornitsky and Potvin [Cannabidiol in humans-the quest for therapeutic targets] defined “high-dose” oral CBD as 150-600 mg/day.

Many consumers experience a satisfactory effect by consuming a 15mg capsule twice per day (morning and night).

Other popular methods of consumption are smoking, vaporization, oromucusal, intranasal, and others. Bioavailability of CBD varies greatly depending on the method of administration. The averages for CBD bioavailability by method of administration are:

• 6% – 15% for oral (swallowed and digested by the GI system)
• 35% for oromucosal (absorbed directly through the mouth)
• 34%-46% for intranasal (applied through the nose)
• 40% for vaporized (absorbed through the lungs)

Sources:

• American Medical Association (AMA)    
• National Institute of Health (NIH) National Center for Biotechnology Information (NCBI)