Why it matters
CBD has poor oral bioavailability because it is highly lipophilic and subject to extensive first-pass metabolism. Estimated bioavailability ranges: oral capsule/gummy ~6%, sublingual tincture ~15–25%, vape ~30–50%, intranasal experimental formulations higher still. Co-administration with high-fat food can multiply oral bioavailability several-fold.
In practice
Practical implication: a 25mg oral CBD dose taken on an empty stomach delivers far less CBD to the bloodstream than the same 25mg taken sublingually or with a fatty meal. Dosing guidance from clinical trials (often 50–600mg daily) cannot be directly translated to consumer products without adjusting for route.
Common confusion
“Nano-CBD” and “water-soluble CBD” products advertise dramatically higher bioavailability. Some increases are real; many marketing claims overstate them.
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