Farnesyl alcohol is an isoprenoid that has been found in aromatic plants and has diverse biological activities.^1,2,3,4 It is an agonist of peroxisome proliferator-activator receptor α (PPARα) and PPARγ (EC50s = 5.5 and 28 µM, respectively, in a reporter assay using CV-1 cells) and increases the expression of mRNA encoding the PPARα targets carnitine palmitoyltransferase 1 (CPT1) and acetyl-CoA synthetase (ACS) in HepG2 cells when used at a concentration of 100 µM.¹ Farnesyl alcohol (250 µM) is a fungal quorum-sensing molecule and inhibits the yeast-to-mycelium conversion in C. albicans.² It decreases the severity of oral candidiasis induced by C. albicans, but does not reduce C. albicans viability or the number of colony forming units (CFUs), in mice immunosuppressed by prednisolone when administered at doses of 1.125, 2.25, and 9 µmol/animal.³ Farnesyl alcohol (0.02-0.1 mg/cm2) repels S. medanensis mites and is toxic to those same mites in a contact assay (LC50 = 0.048 mg/cm2 per vial).⁴ Formulations containing farnesyl alcohol have been used as pesticides in agriculture.