What is 1P LSD

1P-LSD stands for 1-propionyl-lysergic acid diethylamide. It’s a derivative of LSD which essentially means it’s a modified version of the classic LSD-25 that Albert Hofmann discovered in 1943. This molecule is differentiated from LSD by a propionyl group attached to the nitrogen molecule in the indole portion of LSD. The central indole molecule of LSD is the characterizing element of the molecule that’s shared with all other tryptamine-based psychedelics (such as DMT or psilocybin).

1P-LSD itself is only mildly psychedelic. It has a 67-fold less binding affinity for the 5-HT1A receptors, 13-fold less activity at the 5-HT2A receptors, and a 3.5-fold increase at h5-HT2C receptors than LSD-25.