Essential Oil Diffusion: All The Smell-Good Tips You Need To Know (2024)

The most common diffuser on the market is known as an ultrasonic diffuser, which relies on water to create a fine aromatic mist that releases into the air. A nice perk of ultrasonic diffusers is that they act as a small humidifier. Another advantage of ultrasonic diffusers is that not much essential oil is needed to produce a noticeable yet subtle aroma. I love my ultrasonic diffuser from Saje Wellness. It is super easy to use; I simply fill the container with regular water, add in my essential oils, then press the mist button.

While ultrasonic diffusers are worth the investment if you’re interested in adding scent to your home or workspace, they also come with some drawbacks. For instance, they need water to operate, which can prove inconvenient at times, and they require occasional cleaning. The largest qualm about ultrasonic diffusers is that the aromatic scent molecules are diluted with water, which means that top notes, like citrus oils, are extremely volatile and faint in smell. To get a stronger smell, you will need to add more drops of lighter notes, like lemon, orange, and grapefruit. Or you can replenish those top notes more frequently than you would have to with some other aromatic devices, like a nebulizer.

As much as I love my ultrasonic diffuser (I use it just about every day), the nebulizer is regarded as the most powerful diffuser. Nebulizing uses an electric pump to atomize the scent molecules and spray them into the air. As with the ultrasonic diffuser, no water or heat is needed to release the essential oil into the air with a nebulizer. Nebulizers release about 3 milliliters of oil per hour, which is more than other diffusing devices. No wonder they are so therapeutic! However, since they are made of glass, nebulizers don’t often come in the same fun design styles as ultrasonic diffusers.

While nebulizing is my go-to for dealing with acute sickness, ultrasonic diffusing is often the most economical choice for daily use. Nebulizers can be a bit more costly than other diffusing devices and are easily breakable. And because you are not diluting the oils with water like you do when ultrasonic diffusing, nebulizing can use up your oils in a flash. Another downside is that viscous oils, like vetiver, patchouli, and sandalwood won’t really atomize, which will leave you with a vial in need of a deep cleaning. To clean, just rinse the glass with rubbing alcohol.

There is no exact science to diffusing. There’s also no standard recommendation for how long to diffuse your oils. A standard rule of thumb is to diffuse for 15 to 20 minutes, which is more than enough time to saturate a standard-size room with scent molecules. A general best practice is to diffuse roughly 3 to 5 drops of essential oil per 100 mL of water in an ultrasonic diffuser and 5 to 15 drops of essential oil in a nebulizer depending on the note of the oil; however, it’s always best to follow your device’s instructions and experiment with your own amounts. Remember, a little goes a long way.

Nowadays, most diffusers come with a timer setting to help you customize your preferences. But keep in mind there are a number of factors that affect how well diffusion works. First, each essential oil will stay in the air for a different amount of time. Top notes, like peppermint, lavender, and eucalyptus typically evaporate within an hour or two. Middle notes, like rosemary, geranium, and chamomile, often aromatically evaporate within two to four hours. And heavier base notes, like myrrh, cedarwood, and ginger can be detected by olfaction for five or more hours and may even linger for days. Creating balanced synergies can help make a scent last longer or enhance overall therapeutic benefit. For example, combining top notes with complementary base notes helps stabilize the more volatile top note chemicals, making them detectable longer than diffusing just that single note.

The environment also affects diffusion. Room temperature and air circulation can cause molecules to evaporate more or less quickly. For example, warm spaces create greater excitement within bonds of aromatic molecules, which causes them to vanish rapidly. So you may need to add a few extra drops if you’re diffusing in a particularly hot room. Also be wary that any overpowering HVAC system may accelerate spreading the molecules throughout a space. The opposite can also be true; rapid air movement may cause the scent to last for less time.

It’s always imperative that you know the source of your oils but especially when you're diffusing. Make sure that they are unadulterated and not blended with a carrier oil. (Pro tip: Most expensive and precious oils, like rose, neroli, and jasmine are often diluted.) Genuine, bioauthentic essential oils distilled from wild harvested and organic plant material are always the most potent. So be sure to add only 100 percent pure essential oils to the diffuser to avoid the hassle of clogging it and needing to clean it after every use.

While inhalation and diffusing are wonderful and easy ways to integrate essential oils into your routine, keep in mind that you should always diffuse in a well-ventilated area and make sure that what you’re diffusing is safe for pets, children, or anyone else who may be around.