I've been searching but couldn't find any information about the quantitative composition of the OTC dye henna. It is very interesting as it should bee 2-Hydroxy-1,4-naphthoquinone according to an old book, but I have no idea if the OTC product is a pure compound or some mixture. As you can see it is excellent precursor for the making of 2-methoxy analogue of 2C-G-N, it should bee active, don't you think so?