FP-LAD
FP-LAD, also known as fluoro-PRO-LAD or as TRALA-16, is a serotonin receptor modulator of the lysergamide family related to lysergic acid diethylamide. It is specifically a fluorinated derivative of PRO-LAD and an analogue of FLUORETH-LAD.
The drug has been reported to act as a potent ligand of the serotonin 5-HT2 receptors. It had affinities of 0.93nM at the serotonin 5-HT2A receptor, 1.8nM at the serotonin 5-HT2B receptor, and 3.7nM at the serotonin 5-HT2C receptor. FP-LAD was assessed and found to be a full agonist of the serotonin 5-HT2A and 5-HT2C receptors, with and values of 0.48nM and 1.7nM, respectively. It had several-fold greater activational potency than LSD at the serotonin 5-HT2A and 5-HT2C receptors.
The chemical synthesis of FP-LAD has been described.
FP-LAD was patented by Daniel Trachsel and Matthias Liechti and colleagues in association with MindMed in 2023. It had also previously been described in an earlier patent by Andrew Kruegel in association with Gilgamesh Pharmaceuticals in 2022. Hamilton Morris has described synthesizing FP-LAD and/or 1P-FP-LAD with Lizard Labs in 2025. According to Morris, FP-LAD was active but had only about one-fifth of the potency of LSD.