If you’ve ever lit a scented candle to relax or soaked in a lavender bubble bath, you’re already familiar with the power that smell can hold over mood. Of all five senses, it’s the one most closely linked to emotion and memory — likely, scientists think, because the brain’s olfactory processing center is so close to the regions in charge of those other two functions. And there’s an extensive body of research suggesting smell can affect us physically, too: Lab studies have found lavender, for instance, to be effective in calming the nervous system, and neroli, a stimulant, has been shown to increase heart rate.
It makes sense, then, that aromatherapy — the use of scents, most often from essential oils, to enhance well-being — is having a moment right now. With the growing cultural conversation around self-care, people are increasingly incorporating smell into their routines to relax, to fall asleep, to focus, or to get themselves energized. Some estimates put the global market size for aromatherapy at $1.2 billion, and in the U.S., the essential-oil market has grown steadily over the last five years. The market is projected to keep growing at a steady pace through 2025, transforming these products from quaint home remedies to one of the most accessible, and affordable, tools for wellness. Unlike so many other practices in the space, filling your home with a specific scent doesn’t take much effort.
And there’s evidence to suggest it really can work, to an extent — especially, and perhaps only, if you want it to. The science of aromatherapy might best be understood as a study in the power of suggestion. It can also be a strong emotional trigger. Because smell is so tightly tied to memory, the effect of a given scent depends in large part on how you’ve experienced that scent in the past.
The research on aromatherapy is somewhat limited, and a 2012 review concluded that it hasn’t been proven to be a viable treatment for any diagnosable medical conditions. When it comes to improving people’s mental or emotional state, studies have yielded mixed results, but many of them point to belief as a key ingredient: If you believe a scent will make you more joyful, calm, or courageous, it likely will. In 2004, for…