Delta-8 THC Had Very Low Oral Bioavailability and Extensive Tissue Distribution in Rats

Delta-8 THC had oral bioavailability of 3.0%, peak plasma concentration of 13.4 ng/mL at 30 minutes (oral), IV clearance of 5.6 L/h/kg (exceeding hepatic blood flow, indicating extrahepatic clearance), volume of distribution of 108.4 L/kg (indicating extensive tissue distribution), and elimination half-life of 13.9 hours.

Single-dose oral (7.5 mg/kg) and intravenous (1.25 mg/kg) pharmacokinetic study in male Sprague-Dawley rats. Validated bioanalytical method (FDA M10 guidelines) measured delta-8 THC and its metabolites (11-OH-delta-8 THC and 11-COOH-delta-8 THC) in plasma. Non-compartmental analysis determined PK parameters.

Delta-8 THC has surged in popularity but its pharmacokinetics have been poorly characterized. Understanding how it is absorbed, distributed, and eliminated is essential for assessing its safety profile, interpreting drug test results, and potentially developing dosing guidelines.

The 3% oral bioavailability is similar to delta-9 THC, and the extensive tissue distribution explains why cannabinoids can be detected long after use. The finding of extrahepatic clearance (clearance exceeding liver blood flow) suggests the lungs, intestines, or other organs participate in delta-8 THC metabolism.

Rat pharmacokinetics do not directly translate to humans due to metabolic differences. Only male rats were studied. Single-dose study does not capture accumulation with repeated use. Oral dose (7.5 mg/kg) was administered by gavage, not reflecting typical human consumption methods.