By Lia Tabackman
Medically reviewed by Arno Kroner, DAOM
Arno Kroner, DAOM, LAc, operates a private practice in Santa Monica where he specializes in acupuncture, herbal medicine, and integrative medicine.
credit: Temmuzcan/Getty Images
Many people wonder how and why to use an essential oil diffuser. You’ll want to fill it with filtered or bottled water to a diffuser, then add a few drops of essential oil like lavender, peppermint, or eucalyptus. Place it in a large space and turn it on.
Aromatherapy, or the practice of inhaling essential oils, is an ancient form of holistic therapy that has become more popular in mainstream medicine. A limited but growing body of research suggests that it may relieve symptoms from a range of physical and physiological ailments.1 Essential oil diffusers can help your space smell great—and possibly relieve some symptoms—but they are not entirely risk-free.2
How To Use an Essential Oil Diffuser
Before setting up your diffuser, make sure it’s unplugged before filling it with water. “It depends on what type of diffuser you use, but they typically have a water basin with a fill line on the interior. You don’t want to go past the fill line,” Erik Nelson, ND, a naturopathic doctor and integrative medical advisor at Fullscript, told Health.
1. Avoid Hard Water
When filling your diffuser, it’s important to opt for filtered or bottled water. “Hard water” (water with a high mineral content) from the tap may damage the diffuser over time, said Nelson.
2. Add Oil
The next step is to add a few drops of your chosen essential oils to the water basin. Nelson advised anyone using a diffuser to check the instructions to determine the proper “dose” of essential oils to add.
“The first thing you need to remember about essential oils is that they’re super concentrated, so you only need a couple of drops. Any more than that is probably overkill,” said Nelson.
3. Select Where To Put It
Where you place your diffuser will depend on your reasons for using it. If you want to enjoy aromatherapy as part of a bedtime wind-down routine, you should place the diffuser in your bedroom and use it at the end of the day. If you are using a diffuser to feel more focused during the workday, place it in your office. Just be sure to keep it away from other electronic devices to reduce the risk of them getting misted.
4. Turn It On
After picking a location for your diffuser, you can close the lid and turn it on. Essential oil diffusers are pretty low maintenance. Once it’s on, all that’s left to do is go about your day (or night) and let the device do its thing.
5. Clean as Needed
As for if and how you should clean your diffuser between uses, Nelson said to check the manufacturer’s instruction manual that comes with your device. Certain solvents or cleaners may or may not be recommended, depending on your device.
Types of Diffusers
To diffuse, by definition, is to spread something across a large area. Essential oil diffusers do just that. They take a few drops of concentrated essential oil and disseminate them into the air over an extended period of time.
There are a few different types of essential oil diffusers—from electricity-free reed diffusers that soak up essential oils and disperse them around the room to heated diffusers (essential oil warmers) that warm up the oil until it evaporates into the air.
Perhaps the most popular type of diffuser is the ultrasonic diffuser. This electronic device is small enough to sit on your desktop or bedside table. It uses water to diffuse essential oils into the air.
Types of Terpenes
Terpenes are plant-based compounds responsible for how plants smell. All scents found in nature are composed of various combinations and concentrations of different terpenes.3 They are the primary basis of essential oils and are believed to play a part in the therapeutic effects of aromatherapy.1
Examples of terpenes and the essential oils they are found in include:1
- Linalool: Lavender and ylang ylang
- Limonene: Lemon and orange
- Menthol: Peppermint and spearmint
- Pinene: Rosemary
A limited body of research in humans and animals has found that terpenes interact with the brain in particular ways. Terpenes may affect the levels of neurotransmitters like serotonin and dopamine. These chemical messengers are associated with mood and stress.4 Some evidence suggests that limonene may relieve labor pains, ease nausea and vomiting, and elevate low mood. Linalool has also been shown to produce calming effects.1
Which Should You Use?
Picking high-quality essential oils is key to a safe and relaxing aromatherapy experience. The Food and Drug Administration (FDA) minimally regulates the essential oils market. Purity, quality, and efficacy are not guaranteed. When shopping for essential oils, your best bet is to do some research and look for oils that were produced using “clean” distillation methods. These methods avoid the use of harsh solvents like acetone, which can be harmful to breathe in.56
“Clean” distillation methods to look for include:
- Cold-pressed distillation
- Steam-distilled extraction
- Supercritical or subcritical CO2 distillation
- Subcritical CO2 distillation
When looking for an essential oil to use in your diffuser, it’s important to pick a formula labeled for aromatherapy use only. “The bottle will usually say ‘for external use’ or ‘for aromatherapy purposes,’ and you should never use outside of that recommendation,” said Nelson.
If you’re new to aromatherapy or using essential oils for the first time, it may take some trial and error to lock down your favorite scents or scent combinations. Understanding the basic science behind aromatherapy can guide you to finding the optimal fragrance based on the effects for which you’re looking.
Possible Benefits
You may have heard advocates of aromatherapy promise that essential oils can treat symptoms of anxiety and depression. Skeptics may write off the oils entirely as a marketing sham. The truth is likely more nuanced. There’s a growing body of research that suggests that inhaling essential oils may have real therapeutic benefits. Other studies show no improvement in symptoms.7
High-quality clinical studies on the topic are limited. Most of the evidence that exists is in animal studies, has only a small sample size, is based on mostly subjective outcomes, or uses inadequate study methods.7
What the Research Says
A small study found that people who inhaled bergamot essential oil diffused with water had lower salivary levels of cortisol, which is a stress hormone. They reported improvements in fatigue and negative emotions.8
Research and anecdotal evidence in humans and animals suggest that inhaling lavender essential oil may induce relaxation, decrease heart rate, relieve anxiety, and improve mood. A range of small, randomized aromatherapy trials have shown that inhaling lavender may calm people with anxiety related to chest tube removals, cosmetic procedures, intensive care unit (ICU) stays, and upcoming surgeries. None of these subjects had an actual anxiety diagnosis.9
Risks
If you have any pets at home, Nelson stressed that you need to check with a veterinarian before using an essential oil diffuser around them. Certain oils may be toxic to animals when inhaled. People with allergies or who are pregnant, breastfeeding, or have young children should also err on the side of safety. Check with a healthcare provider before using essential oil diffusers.
It’s important to not use essential oils topically without diluting them in a carrier oil, like coconut, rosehip, or jojoba oil. Some essential oils, like tea tree oil, can cause skin irritation if you apply them directly from the bottle to the skin.
“If you notice any changes or negative health effects from using an essential oil diffuser, you should stop using it,” said Nelson. “Make sure you open your windows to get good ventilation in and contact a [healthcare provider].”