Background and Purpose: The cannabinoid type 2 receptors (CB2R) represent a target of increasing importance in neuroimaging due to its upregulation under various neuropathological conditions. Previous evaluation of [¹⁸F]JHU94620 for the non-invasive assessment of the CB2R availability by positron emission tomography (PET) revealed favourable binding properties and brain uptake, however rapid metabolism, and generation of brain-penetrating radiometabolites have been its main limitations. To reduce the bias of CB2R quantification by blood-brain barrier (BBB)-penetrating radiometabolites, we aimed to improve the metabolic stability by developing d₄ and -d₈ deuterated isotopologues of [¹⁸F]JHU94620. Experimental Approach: [¹⁸F]JHU94620-d₈ was further evaluated to characterize its binding properties, metabolic stability, formation of BBB-penetrant radiometabolites and biodistribution in mice and rats. Key Results: The deuterated [¹⁸F]JHU94620 isotopologues showed improved metabolic stability avoiding the accumulation of BBB-penetrating radiometabolites in the brain over time. CB2R-specific binding with K_D values in the low nanomolar range was determined across species. Dynamic PET studies revealed a CB2R-specific and reversible uptake of [¹⁸F]JHU94620-d₈ in the spleen and to a local hCB2R(D80N) protein overexpression in the striatal region in rats. Conclusion and Implications: These results support further investigations of [¹⁸F]JHU94620-d₈ in pathological models and tissues with a CB2R overexpression as a prerequisite for clinical translation.