During a time when our stress levels are running at an all-time high, even wellness skeptics may be willing to anoint their pulse points with a head-clearing essential oil. After all, the herbal healing treatment, which dates back thousands of years and has recently been lauded by everyone from Gwyneth Paltrow and Miranda Kerr to NBA All-Stars, can, in fact, have serious mind-body benefits: “The olfactory senses connect very early in brain wiring to emotional centers, so the distance from when a scent hits the nose to when it hits an emotion is very short,” explained Leslie B. Vosshall, Ph.D., a molecular neurobiologist at the Rockefeller University, in Vogue’s June 2019 issue.

“Breathing in the essential-oil vapor instantly changes our brain patterns and can help us feel calmer and more grounded,” agrees Hope Gillerman, an aromatherapist and author of Essential Oils Every Day: Rituals and Remedies for Healing, Happiness, and Beauty. “They are not a cure” and cannot replace medication, she notes; however, they are one valuable “pathway into taking good care of ourselves.” And don’t we all need to do more of that?

Below, everything you need to know about the best essential oils—and how, when, and where to use them.

What Are Essential Oils Good For?

“Essential oils are a natural, holistic way to address so many of the wellness issues that stem from the stress in our lives,” Gillerman says, adding that their benefits range from improving sleep and easing tension to providing a boost of energy during a midday slump. “Distinct from medications, they are not a cure but a pathway into taking good care of ourselves.”

How to Use Essential Oils

“Smelling essential oils by mindfully inhaling is the quickest way to change your state of mind and stress level,” says Gillerman, who recommends setting an intention before placing a drop of essential oil into the center of both palms. Next, rub your hands together and lift them up to your face, slowly inhaling through your nose. Other options, she notes, include applying an essential oil topically “to cocoon yourself in the aroma” (for example, peppermint dotted on the temple can help alleviate a headache); placing a few drops of a relaxing blend in a bath; or scenting an entire space with the help of an essential oil diffuser.

What to Know Before Buying Essential Oils

In such a crowded market, it can be difficult to know which essential oils to invest in—which is why Gillerman stresses the importance of purchasing essential oils that come directly from an aromatherapist or are certified organic. “Don’t look for a bargain, look for quality,” she says, noting that many essential oils are “adulterated, diluted or overly processed,” which can “degrade the efficacy and irritate the skin and breathing passages.” She also advises against amassing an overflowing collection. Instead, start with the essentials: a cleansing citrus; a mood-enhancing flower, such as lavender; a relaxing resin or root (think frankincense, cedarwood, or vetiver); and a stimulating scent, like basil, or rosemary.

Blends May Be Best

“Blends of two to five essential oils are more powerful than a single oil,” she says, explaining that the oils work in tandem to better target specific health and wellness issues. And what can be an overpowering scent on its own can be balanced when mixed with other oils. To wit, “ylang ylang by itself has a heavy, almost medicinal sweetness that many say they don’t like. But when combined with other essential oils, the sweetness softens into a warm, slightly fruity aroma that makes this oil a joyous component of any ‘happiness blend.’”

The Best Essential Oils for Every Issue

For anxiety: vetiver, neroli, clary sage, and geranium

For sleep and relaxation: lavender, chamomile, and rose

For mental focus: peppermint and rosemary

For energy: eucalyptus, peppermint, rosemary, cypress, and cardamom

For a mood boost: bergamot, ylang ylang, jasmine, lime, and lemon

For sore muscles: vetiver, peppermint, helichrysum, and pine