Pregnenolone-d 4 is the deuterium labeled Pregnenolone. Pregnenolone (3β-Hydroxy-5-pregnen-20-one) is a powerful neurosteroid, the main precursor of various steroid hormones including steroid ketones. Pregnenolone acts as a signaling-specific inhibitor of cannabinoid CB1 receptor, inhibits the effects of tetrahydrocannabinol (THC) that are mediated by the CB1 receptors. Pregnenolone can protect the brain from cannabis intoxication. Pregnenolone is also a TRPM3 channel activator, and also can weakly activate TRPM1 channels.