Taking a test, going on a first date, or your first day at work can be filled with a bundle of nerves. Breathing in and out and counting to 10 can help alleviate feelings of fear or worry, but for 40 million adults in the U.S. with an anxiety disorder, telling yourself to stop being nervous or not to panic can make it worse. Essential oils can help decompress and de-stress through the healing power of scent.

It's not completely understood how essential oils work, but their power may be due to a relationship between smell and the brain. Scent receptors in the nose send chemical messages via the olfactory nerve to the limbic system - a primitive area of the brain that deals with basic emotions, including anger and fear, and memories. A 2013 study in the journal Current Drug Targets found olfactory signals from essential oils are thought to impact brain chemical production, thereby affecting both mental and physical health.

Essential oils are natural, extracted from flowers, leaves, bark, or roots of plants, and can provide much-needed relief and healing for a variety of ailments, including anxiety. Below are the six best essential oils for alleviating anxiety, from lavender to frankincense.

Lavender

Lavender is considered to be the most common essential oil for its calming, relaxing effect. It helps with sleep, restlessness, panic attacks, and general nervous tension. Patti Lyons, owner of Peace Valley Lavender Farm in Doylestown, Pa., believes "the power of lavender to stimulate and supplement in the body's healing forces is unmatched by modern pharmaceuticals."

It can kill pathogens in the air and in nasal sinuses and respiratory airways. Lyons states lavender is also a nerve tonic and an antidepressant, boosting our spirits as well as helping to beat "the blues" that accompany immune stress and illness.

A 2009 study in the journal Human Psychopharmacology found orally administered lavender essential oil led to an increase in heart rate variation compared to the placebo, while watching an anxiety-provoking film. This suggests lavender has anxiolytic effects (also anti-panic or anti-anxiety agent).

Rose Oil

Rose oil is the second most popular essential oil after lavendar for alleviating anxiety and depression. This is shown to help with panic attacks, grieving, and shock. A 2014 study in Iranian Red Crescent Medical Journal found a 10-minute inhalation and foot bath with rose oil reduced anxiety in women who've never given birth.

Chamomile

This peaceful, calming scent provides a range of benefits from inner harmony to decreasing irritability, overthinking, anxiety, and worry. A 2012 study in the journal Alternative Therapies in Health and Medicine found chamomile oil could provide meaningful antidepressant activity in addition to its observed anxiolytic activity. In other words, it could potentially ease anxiety symptoms in patients.

Bergamot

Bergamot is normally used to treat depression via energy, but it's also known to reduce stress. Typically, bergamot is extracted from the rind or peel of the fruit, which leaves an aroma that is citrusy but sweet. A 2011 study in the journal Phytotherapy Research: PTR suggests using blended essential oil with lavender and bergamot can help treat depression or anxiety.

Ylang Ylang

Ylang Ylang has a romantic, flora aroma that consists of several components, including benzyl acetate, benzyl benzoate linalool, caryophyllene, among many others. It can be used to treat anxiety and depression because it has an uplifting effect. A 2006 study in the journal Taehan Kanho Hakhoe Chi found ylang ylang oil in combination with bergamot and lavender could reduce “psychological stress responses and serum cortisol levels, as well as the blood pressure of clients with essential hypertension" by taking it once a day in four weeks.

Frankincense

Frankincense, also known as "olibanum" is an aromatic resin that can be used to treat depression and anxiety due to its calming effect. A 2008 study in the journal Taehan Kanho Hakhoe Chi found this oil mixed with bergamot and lavender had a positive effect on pain and depression in hospice patients with terminal cancer. A simple aroma hand massage had a healing effect when essential oils were used.

It's best to use pure essential oils that are not diluted with chemicals or additives for better and more natural relief.