How it works: “Eucalyptus oil acts as an expectorant, helping to clear mucus from the respiratory passages,” says Jennie Harding, an aromatherapist and the author of The Essential Oils Handbook ($13, amazon.com). Boil 1 quart of water, let it cool slightly, then pour it into a bowl. Add 4 drops of oil, drape a towel over your head, and lean over the steam, inhaling for 10 to 15 minutes.
Good to know: If you’re pregnant or under a doctor’s care, see your physician before trying any essential oil.
2 of 6Grant Cornett
Try it when: You have a tension headache.
How it works: Peppermint contains menthol, a natural anesthetic that dulls pain receptors. In fact, one study found that applying a peppermint-oil blend to the forehead was just as effective for pain relief as taking acetaminophen. However, peppermint oil can cause irritation if applied directly to the skin, so dilute it first. Add 2 drops to 1 teaspoon of a carrier oil (an unscented base oil, such as sweet almond), then massage into skin.
Good to know: Studies show that consuming peppermint oil may help alleviate stomach discomfort. Take ½ teaspoon, or try a coated tablet (available at drugstores).
3 of 6Manfred Koh
Try it when: You need a mood boost.
How it works: Research suggests that jasmine oil may act as a natural antidepressant when massaged into the skin. Add 5 drops to a few ounces of a carrier oil, suggests Harding, then rub into shoulders.
Good to know: Jasmine oil may help you focus, too. When study subjects were asked to note their attentiveness before and after applying the oil to their skin, they rated themselves more alert after smelling the scent. Dab onto temples when you’re feeling energy-sapped.
4 of 6Grant Cornett
Try it when: You have a mouth sore or a toothache.
How it works: “Eugenol, a chemical in clove-bud oil, is analgesic and antibacterial, which makes it effective for treating pain in the mouth,” says dentist Jonathan B. Levine, the director of the New York University CE Advanced Aesthetics Program in Dentistry, in New York City. (In fact, dentists mix it with zinc oxide to use in temporary fillings.) Mix 1 drop in 1 cup of water; apply directly with a cotton swab.
Good to know: Gargling with a mixture of water and 1 drop of clove-bud oil can help neutralize bad breath.(But don’t swallow. The oil can cause an upset stomach.)
5 of 6Grant Cornett
Try it when: You’re battling breakouts.
How it works: Tea-tree oil has antimicrobial properties and works to help minimize the bacteria responsible for pimples, says Howard Sobel, a New York City cosmetic dermatologist. Mix 5 drops in 4 tablespoons of aloe vera gel and apply as a toner after cleansing, says Harding.
Good to know: Tea-tree oil can also help with dandruff. A study showed that people who used a shampoo with 5 percent tea-tree oil reported a 41 percent reduction in flakes. Add 1 drop to a dollop of your own shampoo before sudsing up.
6 of 6Grant Cornett
Try it when: You’re feeling stressed.
How it works: The scent of lavender is thought to calm the nervous system. In one study, people exposed to the smell of lavender oil while waiting for a dental appointment reported feeling less anxiety than did those in an unscented room. Try adding 4 to 6 drops to a warm bath or mixing the oil with water in a spray bottle to mist into the air. (Bonus: Some research suggests it might also help fight hair loss when massaged into the scalp.)
Good to know: To relieve sore muscles, combine 5 drops with 5 drops of peppermint oil and 4 teaspoons of a carrier oil, then massage into skin.