Plumbagin or 5-hydroxy-2-methyl-1,4-naphthoquinone is an organic compound with the chemical formula C11H8O3.

It is regarded as a toxin[1] and it is genotoxic[2] and mutagenic.

[3] Plumbagin is a yellow dye,[1] formally derived from naphthoquinone.

It is named after the plant genus Plumbago, from which it was originally isolated.

[4] It is also commonly found in the carnivorous plant genera Drosera and Nepenthes.