Clinical Trial Finds Delta-8 THC Holds Similar but Milder Effects than Delta-9 THC

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According to new research published in Drug and Alcohol Dependence (1,2), consuming delta-8 tetrahydrocannabinol (THC) orally causes dose-dependent psychoactive effects similar to delta-9 THC but were milder. The clinical trial sought to investigate the effects delta-9 THC and delta-8 THC have. Researchers affiliated with Johns Hopkins University (2) utilized 19 healthy adults to gather their data. Participants were given brownies that had been infused with synthetic delta-8 THC (10, 20, 40 mg), synthetic delta-9- HC (20 mg), or a placebo (1,2). The trial made history as the first study in over five decades to look into the effects detla-8 THC has on human subjects (2).

Researchers mentioned (2), “Overall, ingestion of delta-8 THC produced dose-dependent increases in subjective, cognitive performance, and physiological outcomes that were qualitatively similar to delta-9 THC. Consistent with prior findings, delta-8 THC exhibited lower potency compared to delta-9 THC at equivalent doses, though this reduced potency was overcome by increasing the delta-8 THC dose. Together, these findings demonstrate that delta-8 THC products have the potential to produce psychoactive and physiological effects that are comparable to delta-9 THC.”

Study authors additionally commented (2), “With the widespread availability of retail delta-8 THC to consumers as a byproduct of the 2018 Farm Bill, the findings from the present study underscore the importance of establishing regulatory frameworks that address safety, labeling, and consumer education related to delta-8 THC products.”

Delta-8 THC does exist organically in the cannabis plant but in small amounts (2). NORML mentioned that “elevated quantities of delta-8 THC in commercially available products are typically the result of a chemical synthesis during which manufacturers convert hemp-derived CBD to delta-8 THC,” (2).

At the end of the study, researchers found that delta-8 THC possessed dose-dependent psychoactive effects that were similar to delta-9 THC and that delta-8 THC may pose similar risks (1). Study authors concluded that (2), “Delta-8 THC demonstrated dose-dependent psychoactive effects qualitatively similar to delta-9 THC but with reduced potency, possibly due to lower biotransformation to its 11-OH metabolite. Importantly, higher doses of delta-8 THC offset reduced potency, as 40 mg delta-8 THC and 20 mg delta-9 THC produced similar effects; this is noteworthy considering consumers generally perceive delta-8 THC as less harmful or intoxicating than delta-9 THC. These findings inform regulatory decisions and public education, though further research on emergent cannabinoids is needed.”

References

1. C. Austin Zamarripa, Tory R. Spindle, Destiny Schriefer, Edward J. Cone, Ruth E Winecker, Ronald Flegel, Eugene Hayes, Lisa S. Davis, David Kuntz, Ryan Vandrey, A Within-Subject Cross-Over Trial Comparing the Acute Effects of Oral Delta-8-Tetrahydrocannabinol and Delta-9-Tetrahydrocannabinol in Healthy Adults, Drug and Alcohol Dependence, 2025, https://doi.org/10.1016/j.drugalcdep.2025.112676.
2. Norml. Clinical trial: Oral delta-8 THC effects similar but milder than delta-9 THC https://norml.org/news/2025/04/17/clinical-trial-orally-administered-delta-8-thc-possesses-similar-but-milder-effects-than-delta-9-thc/ (accessed Apr 24, 2025).