Melissa is one of the most expensive oils in the trade, and one of the most faked. The plant yields so little that a kilo takes several tonnes of lemon balm. Cheap melissa is almost always cut with lemongrass or citronella, which are far cheaper sources of the same citral. Citral gives it the lemon character, softened by citronellal into something rounder. Against herpes viruses in the dish it cut infection by around 98%, at doses that left cells unharmed.^[1]