Tagetes is a marigold, but not the garden one, and the oil is pungent enough to need real caution. Tagetone and dihydrotagetone give it a fruity, bitter, herbaceous smell that is hard to place. In activated immune cells it damped nitric oxide and reactive oxygen production about as well as standard reference compounds.^[1] In mice it reduced depression-like behaviour after an inflammatory challenge, restoring stress hormone and growth factor levels.^[2] IFRA restricts it in fragrance, partly over phototoxicity, so it belongs in low dilution only.