H4CBD (hydrogenated CBD, tetrahydrocannabidiol) is a synthetic cannabinoid that was first synthesized by Alexander R. Todd in 1940 derived from the catalytic hydrogenation of cannabidiol.
H2-CBD and 8,9-dihydrocannabidiol have also been referred to as "hydrogenated CBD", which may cause confusion.
In 2006, it was discovered that H4CBD has a binding affinity of 145 nM at the CB1 receptor and potential anti-inflammatory effects independent of its cannabinoid receptor action. In contrast, CBD has been found to bind to the CB1 receptor as an inverse agonist/antagonist with a K<sub>i</sub> ranging from 3.3 to 4.8 mM.
In 2023 H<sub>4</sub>CBD epimers were elucidated using NOESY and COSY NMR spectroscopic techniques, while the inclusion of LC-MS and SCFC were used to isolate individual diasteromers.