Lapachol is a natural organic compound isolated from the lapacho tree. This tree is known botanically as Handroanthus impetiginosus, but was formerly known by various other botanical names such as Tabebuia avellanedae.Lapachol is also found in other species of Handroanthus.
Lapachol is usually encountered as a yellow, skin-irritating powder from wood. Chemically, it is a derivative of naphthoquinone, related to vitamin K. Once studied as a possible treatment for some types of cancer, lapachol's potential is now considered low due to its toxic side effects.
 Lapochol at R&D Chemicals.
 Lapochol at CromaDex.
 Record, Samuel J.. "Lapachol" pages 17-19. In: Tropical Woods (1925).
 Susan O. Grose and Richard G. Olmstead. 2007. "Evolution of a Charismatic Neotropical Clade: Molecular Phylogeny of Tabebuia s.l., Crescentieae, and Allied Genera (Bignoniaceae)". Systematic Botany 32(3):650-659.
 Louis F.Fieser. The Scientific Method pages 163-191. Reinhold Publishing Corporation, New York, 1964
 Felício AC, Chang CV, Brandão MA, Peters VM, Guerra Mde O (2002). "Fetal growth in rats treated with lapachol". Contraception 66 (4): 289–93. doi:10.1016/S0010-7824(02)00356-6. PMID 12413627.
 Oral toxicology studies with lapachol. Morrison, Robert K.; Brown, Donald Emerson; Oleson, Jerome J.; Cooney, David A. Toxicology and Applied Pharmacology (1970), 17(1), 1-11.
 Guerra Mde O, Mazoni AS, Brandão MA, Peters VM (2001). "Toxicology of Lapachol in rats: embryolethality". Brazilian journal of biology = Revista brasleira de biologia 61 (1): 171–4. PMID 11340475.
 de Cássia da Silveira E Sá R, de Oliveira Guerra M (2007). "Reproductive toxicity of lapachol in adult male Wistar rats submitted to short-term treatment". Phytotherapy research : PTR 21 (7): 658–62. doi:10.1002/ptr.2141. PMID 17421057.