Review of delta‐8‐tetrahydrocannabinol (Δ8‐THC): Comparative pharmacology with Δ9‐THC
Michael Tagen, Linda E. Klumpers
British Journal of Pharmacology August 1, 2022 DOI: 10.1111/bph.15865 (opens in new tab)
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Study at a glance
AI-extracted from the abstract| Characteristics | Review Peer reviewed |
|---|---|
| Topics | Cannabis |
| Key findings | The pharmacokinetics and pharmacodynamics of delta-8-THC and delta-9-THC are very similar, with delta-8-THC's reduced potency explained by weaker CB1 receptor affinity. |
Abstract
The use of the intoxicating cannabinoid delta‐8‐tetrahydrocannabinol (Δ8‐THC) has grown rapidly over the last several years. There have been dozens of Δ8‐THC studies dating back over many decades, yet no review articles have comprehensively covered these findings. In this review, we summarize the pharmacological studies of Δ8‐THC, including receptor binding, cell signalling, in vivo cannabimimetic activity, clinical activity and pharmacokinetics. We give special focus to studies that directly compared Δ8‐THC to its more commonly studied isomer, Δ9‐THC. Overall, the pharmacokinetics and pharmacodynamics of Δ8‐THC and Δ9‐THC are very similar. Δ8‐THC is a partial agonist of the cannabinoid CB1 receptor and has cannabimimetic activity in both animals and humans. The reduced potency of Δ8‐THC in clinical studies compared with Δ9‐THC can be explained by weaker cannabinoid CB1 receptor affinity, although there are other plausible mechanisms that may contribute. We highlight the gaps in our knowledge of Δ8‐THC pharmacology where further studies are needed, particularly in humans.
Comparable studies
Other narrative reviews on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Causal association between cannabis and psychosis: examination of the evidence | 2004 | Review | |
| Cannabis sativa: A comprehensive ethnopharmacological review of a medicinal plant with a long history. General (historical and pharmacological review) | 2018 | Review | |
| Psychiatric effects of cannabis | 2001 | Review | |
| Beyond THC: The New Generation of Cannabinoid Designer Drugs | 2011 | Review | |
| Cannabidiol, a Cannabis sativa constituent, as an antipsychotic drug | 2006 | Review |
Citations in the library
Cited by 14
- Delta-8-THC association with psychosis: A case report with literature review Frontiers in Psychiatry February 20, 2023
- Perceptions of Delta-8 THC and the Impact of a Brief Educational Video Intervention for College Students. The journal of behavioral health services & research April 1, 2026
- Side-Chain Homologs of Δ9-THC, Δ8-THC, and HHC Reveal Pathway Bias at CB1R and CB2R Cannabinoid Receptors. Molecular Neurobiology August 20, 2026
- Pharmacokinetic study of delta-8-tetrahydrocannabinol in male rats using a validated bioanalytical method. Journal of Analytical Toxicology April 30, 2026
- Portrayal of Delta-8 Tetrahydrocannabinol (THC) on YouTube. Substance Use & Misuse 2025
and 9 more in the library
Cites 4
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