The 5 Most Common Mistakes Made When Diffusing Essential Oils

If you’re reading this, chances are you use an essential oil room diffuser, or you know someone who does. There are many different types of diffusers, but each one has the aim to disperse essential oil molecules into the air so we can inhale them. We may use these devices to simply make a room smell good, but increasingly we use them because we want to gain health benefits by improving our mood (i.e. de-stress, reduce anxiety, help us focus) or directly support us with respiratory issues (i.e. cold, flu, allergies).

Diffusers can be extremely beneficial, but there are several important factors that need to be considered when using them. Here are 5 common mistakes I find people making when diffusing essential oils, and what you can do instead:



One of our body’s main objectives is to protect us from external dangers. Our nose and our sense of smell play a key role as protector. As scent molecules come through the nose and trigger odor receptors, they assess “the situation” and relay the information to our brain. Depending on what it “reads,” our brain initiates appropriate responses to our nervous system. This is how our body, for example, responds to the dangers of smoke or gas.

When we diffuse essential oils in a room over a long period of time, our nose gets a constant stream of the same odor molecules coming through. To keep our nervous system from exhausting itself with this continuous stimuli, the receptors experience something called olfactive fatigue, also known as temporary sensory fatigue, or olfactory adaptation. Odor receptors stop sending messages to the brain about a lingering odor after a few minutes and instead focus on novel smells - like gas and fire - always keeping a lookout for danger. Olfactory fatigue is a good thing; it helps us to get used to smells so that our nervous system doesn’t become overloaded, and we can be ready to respond to new smells.

Importantly, Robert Tisserand, co-author of the book Essential Oil Safety, assesses that, by continuously diffusing, you aren’t getting an increase in benefits from the essential oils. Instead, there is evidence that the body becomes stressed in various ways.

HERE’S WHAT YOU CAN DO: diffuse over short periods of time: ideally 10-15 minutes, but maximum 30-60 minutes on and 30-60 minutes off. By giving your nose a break, you give your body a break. And you’re going to enjoy smelling the essential oils more because you’ll be better able to smell them - less olfactive fatigue. You also use less essential oils, which is good for the wallet and good for the environment.

Learn how to diffuse essential oils effectively & safely here



We read all the time about how helpful certain essential oils, like lavender, are for helping us sleep. And many people choose to diffuse during the night while they sleep. But is it safe to leave the diffuser on all night? Here's why it's best not to:

At night your body is focused on resting and repairing muscles, organs and other cells. For one, you begin the night in non-REM sleep and spend most of your resting time there. During this time your brain becomes less responsive to the outside world, and it gets harder to wake up. Your thoughts and most body functions slow down. Inhaling odor molecules are not a priority for the body - those lavender molecules are not a priority for the body - they may, in fact, be a distraction.

HERE’S WHAT YOU CAN DO: if you want the support of essential oils for sleep, consider diffusing them 30 minutes before you go to sleep. Put the diffuser on in your bedroom, preferably not to close to your bed (I like to put it on a dresser or table across the room from the bed) and close the door behind you - ideally watch TV or read in another room - and allow the bedroom to fill with the scent of the essential oil(s). When you are ready to go to sleep, the diffuser is off and you peacefully drift off to sleep. Because the room is already filled with essential oil molecules (you’ve created this beautiful spa sanctuary), you will most likely start to feel calmer and more relaxed just entering the space. The essential oils have the role of supporting you in preparation for sleep. They leave the job of restoration and repair during sleep for the body.



Often people want to add a lot of essential oil drops to their diffuser because they believe the scent and the effect will be more impactful. Well, your sense of smell has something called an odor detection threshold which is defined as the most minimal concentration of a substance that can be detected by a human nose. Each person has a different threshold level because it’s dependent on many factors, including genetics, your age, the environment you are in (are other smells a distraction), as well as your health (how strong is your sense of smell).

You see, whether you can smell a scent or not, your nose is taking in the molecules, and an effect is being had. To keep your body, and especially your nervous system, from being overloaded with odor molecules, it is safest to keep the amount of essential oil to between 5-6 drops, depending on the size of the room. And, as stated above, if you stick to small bursts of diffusing, as opposed to continuous, you will be able to detect the scent much better.

HERE’S WHAT YOU CAN DO: firstly, practice improving your sense of smell - it’s a “muscle” that you need to train on a regular basis, or it will grow weak over time. I discuss this further in my other blog post “5 Reasons to Care About Your Sense of Smell”. Secondly, try eliminating other odor distractions in the room. Unlike many synthetic air care products that are meant to mask odors, essential oils do not really play this role. They may have antibacterial properties, which can help to sanitize a space when germs are in the air from a cold or flu, but they aren’t meant to be used with the intensity of your regular store brand air care product. Remember, less is more and a little goes a long way.



A pet’s sense of smell is much greater than a human’s. For example, a dog can smell 15x more than we humans can. Their odor sensations are heightened and when you diffuse in a room, they are sensing that smell exponentially more than you. Their bodies, like ours, respond to the external stimulus and can get burdened and stressed with overexposure.

HERE’S WHAT YOU CAN DO: firstly, always give your pet an “out”, by leaving a door and/or window open so they can leave the room or provide ventilation. Secondly, test the essential oil you want to diffuse with your pet and see how they respond - place one drop of essential oil in a tissue and gently wave it near their nose from a slight distance. See how they respond - do they move towards you or do they move away? This is their way of speaking to you and letting you know what they like and don’t like. As with humans, use the diffuser for short periods of time and keep the device as far away from pets as possible.



It's generally safe to use some essential oils while you're pregnant, as long as you're healthy and you're careful with them. However, avoid using them in the first trimester, if possible. Always remember that essential oils are highly concentrated substances. They are powerful, so it's important to use them sparingly. And if you are pregnant, or have a small baby, this especially holds true.

HERE’S WHAT YOU CAN DO: while pregnant, diffuse a maximum of 5-10 minutes at a time, using the smallest dose possible (2-3 drops) and make sure to have good ventilation. Use gentle oils only. As for babies, the same premise applies, making sure to avoid oils high in 1,8 cineole like eucalyptus, tea tree and rosemary.

Overall, room diffusing is a wonderful way to get the benefits of essential oils when you do it wisely.

Learn how to diffuse essential oils effectively & safely here

Note: I did not go into detail (at this time) about particular essential oils that may or may not be appropriate for diffusing. Please do your research, use reputable aromatherapy book sources before diffusing any essential oil, as there are several that can be irritating to the lungs.


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