I just returned from a work trip to the Maldives. Before I flew, I bought a 3-pack of Origins Peace of Mind On-the-spot Relief. I used to use the Peace of Mind Sensory Therapy Diffuser, which was a plastic box that you open and breathe the scent in. The diffuser lasts a really long time but I think it's been discontinued, so I had to settle for On-the-spot Relief instead. I got the 3-pack for less than S$60 at Changi Airport, works out to about S$20 a bottle which is ok!
I know a lot of Asian/Chinese bring medicated oil on their travels for tummy aches and headaches - it is minty and really helps! But the main drawback of medicated oil is that it smells very pungent and I try not to use it in public because people usually recognise the scent of medicated oil and start asking "Are you ill?" Plus, some people dislike the strong scent of medicated oil (ingredients include eucalyptus, menthol, camphor, methyl salicylate and peppermint oil, sometimes clove oil depending on the brand). Origins Peace of Mind is a good alternative if you find the scent of medicated oil too strong. (Of course, medicated oil is much cheaper.)
Origins Peace of Mind contains peppermint, eucalyptus and basil, which smells really soothing and calming. I like rubbing it on my temples and on the back of my neck - it's just a little tingly. The scent lasts for about an hour - it fades pretty quickly. I would say it's a 'nice-to-have' but it is on the pricey side for a tiny 15ml bottle that may be used up very quickly if you have a tendency to get stressed or get migraines easily. Would I repurchase? Yes, it's nice to have on travels and very soothing on the plane!