1P-LAD4, 1P-LSD4, 1-Propionyl-lysergic acid diethylamide4

The Chemistry of 1P-LSD

The scientific literature contains little information about 1P-LSD. Its first date of synthesis is unknown, and mentions of it only start to appear in the psychonaut community around January 2015.1

1P-LSD is a derivative of LSD and a homolog of ALD-52. It belongs to the ergoline family of compounds, which includes LSD. The chemical structure of 1P-LSD differs from LSD by having a propanoyl group on the nitrogen atom in the indole ring.

The Pharmacology of 1P-LSD

A recent study found Ki values for 1P-LSD of 637 nM, 196 nM, and 13.0 nM, at serotonin 5-HT1A, 5-HT2A, and 5-HT2C, respectively.2 Receptor activity studies indicated that 1P-LSD is a very weak partial agonist at the human 5-HT2A receptor compared to LSD, but it did induce the head-twitch response in mice. However, 1P-LSD showed no agonist activity at 5-HT2A and 5-HT2C despite showing comparatively high affinity those receptors compared to LSD. Additional work indicated that 1B-LSD produced a dose-dependent increase in head twitches.3

The data from a November 2019 study indicates that 1P-LSD is a prodrug of LSD.2 High levels of LSD were found in the blood plasma of rats after they were administered 1P-LSD subcutaneously.

The Applications and Potential of 1P-LSD

As a prodrug of LSD, 1P-LSD may provide drug formulation options due to its different solubility and other physical properties.

  1. Halberstadt AL, Chatha M, Klein AK, et al. Pharmacological and biotransformation studies of 1-acyl-substituted derivatives of d-lysergic acid diethylamide (LSD). Neuropharmacology. November 2019:107856. doi:10.1016/j.neuropharm.2019.107856
  2. Beharry S, Gibbons S. An overview of emerging and new psychoactive substances in the United Kingdom. Forensic Science International. 2016;267:25-34. doi:10.1016/j.forsciint.2016.08.013
  3. Brandt SD, Kavanagh PV, Westphal F, et al. Return of the lysergamides. Part I: Analytical and behavioral characterization of 1-propionyl-d-lysergic acid diethylamide (1P-LSD). Drug testing and analysis. 2016;8(9):891. doi:10.1002/dta.1884
  4. PubChem. 1-Propionyl-lysergic acid diethylamide. https://pubchem.ncbi.nlm.nih.gov/compound/119025985.