Aromatherapy is a complementary treatment that uses essential oils to enhance relaxation and boost mental sharpness. If you love scents—concocted by distilling volatile oils from the flowers, leaves and bark of plants—you’ll enjoy the varied aromas that deliver aromatherapy’s message. By making sure you get only essential oils—many fragrant oils contain hormone-disrupting phthalates—you’ll get the aromas’ benefits without any downsides.

But aromatherapy’s not a cure-all. Research tells us that good scents make sense when you need a little ‘nudge.’ Brown University researchers note in a review of 18 aromatherapy studies, “odors can affect mood, physiology and behavior”—most likely because the nerves that carry odor signals to your brain communicate directly with areas involved with emotion and learning. This may explain aromatherapy’s substantial effects, and the list is impressive:

Grapefruit squashes food cravings. In a study from Japan’s Osaka University, the scent of a grapefruit’s essential oil reduced appetite.

Lavender, sandalwood and sweet orange for relaxation, reduced anxiety. In one study, 12 breast cancer survivors reported drops in anxiety when they received a series of half-hour massages using only essential oils scented with lavender, sandalwood or sweet orange. The researchers noted that an aromatherapy massage could be a drug-free way to help handle the worries that can linger once cancer treatment ends.

And more research found lavender eased the pain of needle injections and helped reduce post-op pain for kids who’d had their tonsils out. Furthermore, sniffing a mix of lavender, roman chamomile and neroli (citrus orange/floral) helped ease anxiety, improved sleep and stabilized blood pressure in heart patients receiving stents to open blocked arteries in the heart.

Neroli for calm. The floral scent of neroli eased anxiety in a lab study at Japan’s Taichung Veterans General Hospital. Sniffing neroli temporarily lowered blood pressure and heart rate slightly in other research, too.

Roses for deeper sleep. Sniffing rose essential oil led to deeper, longer sleep in a research study from Japan’s Mie University Graduate School of Medicine.

Rosemary for better memory. Sniffing the scent of rosemary helped people in a study from the UK’s University of Northumbria recall specific events from the past with greater ease and become more likely to remember things on future to-do lists.

Peppermint oil for post-op recovery. One study found inhaling the scent of peppermint oil eased post-surgery nausea.

Ready to breathe in the benefits? Follow these strategies for great results:

Choose good-quality essential oils that you like. Use real essential oils, not perfume oils. Sniff before you buy. Even if a scent has proven benefits, it won’t help much if you can’t stand the way it smells! Fortunately there are lots of options.

Use just a little. Add 8-10 drops to your next bath, five drops to a basin of warm water for a heavenly foot soak, or five to six drops to a carrier oil like jojoba, almond, olive or grapeseed for an out-of-this-world massage. You can also add a few drops to a cup of hot water to let the scent waft through a room.

Mix, match and have fun. Try a few drops of this…a few drops of that. One study found 80 percent of nurses working in a hospital emergency department were very stressed out. But after they received aromatherapy massages—some with a scent that combined essential oils of lavender, ylang ylang, bergamot and patchouli—while listening to calming music, only 8 percent reported feeling very stressed.

Stay safe.

• Only use products with essential oils, never any with phthalates.
• All oils, even essential oils, can trigger negative reactions. Watch for allergic reactions.
• Never take an essential oil internally.
• Don’t put undiluted oils on your skin.
• Never use near your eyes.
• If you are pregnant, have asthma or a history of allergies, or if you have cancer or were treated for cancer, don’t use essential oils without consulting your doctor.