Pentadecanoyl-L-carnitine is a cannabinoid (CB) receptor agonist (EC50s = 3.7 and 3.2 µM for CB1 and CB2 receptors, respectively, in a cAMP modulation assay). It is also an agonist at the serotonin (5-HT) receptor subtypes 5-HT1A and 5-HT1B (EC50s = 9.6 and 9.3 µM, respectively) and an antagonist at histamine H1 and H2 receptors (EC50s = 10.9 and 6.1 µM, respectively). Pentadecanoyl-L-carnitine inhibits T cell proliferation in an SAg primary human cell system and reduces chemokine (C-C) motif ligand 2 (CCL2) levels in an Mphg primary human cell system.