Pipermethystine (1), 3alpha,4alpha-epoxy-5beta-pipermethystine (2) and awaine (3) were isolated from the aerial parts of kava (Piper methysticum G. Forster, Piperaccae) and identified by HRMS and NMR spectroscopic analysis. I was concentrated in the stem peelings and leaves. 2 and 3 are new alkaloids with 2 found only in cv. Isa among the 11 cultivars examined, and 3 occurred primarily in young leaves of all cultivars. The stem peelings have been used in recent years as a source of kavalactones in kava dietary supplement industry. Quantitative aspects of these piperidine alkaloids in P. methysticum and their potential activities on human physiology are discussed. (C) 2003 Elsevier Science Ltd. All rights reserved.