I've never heard of such a thing. When folks use the term "essential oils" they're generally meaning plant extract based preparations that are applied to the skin or dispersed in a diffuser or such for the aroma to permeate the air - versus something that's ingested. For clarification, is this what we mean, or referring to something to be taken internally? Essential oils as I've defined here are used (by others, not me) not as a preventative measure (as indicated above) might be done for hangover, but rather to produce an effect for an existing condition - for example, some make claims that a certain oil will produce a relaxation effect or reduce a headache. What I'm going to say may be controversial and others for sure would probably argue differently, but my take as a person with a scientific bent is that surely some aromas as well as some ritual practices which may include use of essential oils produce a sensation of relaxation or calm or a feeling of being mentally stimulated and beyond that much of the claims folks make boil down to placebo effect - expectation of a positive result which then is subject to confirmation bias.