From Nurse to Aromatherapist: The Science of Essential Oils

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I'm a environmental toxins lawyer turned clean living coach who is obsessed with morning sunshine, Ningxia Red and all things holistic living (but for real life).  Catch me over on Insta and come say hi.


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My guest today is Holly Brandenberger, and if you have ever searched for anything related to essential oils on Instagram, you likely have come across her aromatherapy account @scienceofessentials. Holly is the face behind that account. She is a registered nurse and aromatherapist and is at the cutting edge of essential oils research in a hospital setting.

In this interview, you’ll hear from her about the actual science of how essential oils work, what the latest research says about essential oil uses, and brain health and pain management. We also dive into simple ways to use essential oils in your homes, the best oils for hair growth, and stress, natural remedies for congestion and kids, sleep, DIY skincare, and even the short list of oils that Holly could never live without.

In this episode, we discuss: 

  • How aromatherapy can be used in hospitals to calm patients

  • The neuroscience behind why essential oils work

  • How to use essential oils safely

  • Best practices for using essential oils with children

  • Best oils for hair growth, sleep, memory, and focus

  • Debunking misconceptions about oils like lavender

Why Essential Oils?

In my toxin-free living world, I promote using essential oils as a safe fragrance because I want people to get rid of anything that has phthalates, hormone disruptors, or any synthetic fragrance. My big thing is to get them all out of your house for your health. If you want your home to smell like you know flowers or candles, or if you miss those scents in your home, bring in quality, pure essential oils. People know it’s a safe alternative, but when I start talking about the health benefits of essential oils, I lose people.

They started using essential oils because they wanted their house to smell good and not spread synthetic fragrances in the air. But then they experience some amazing transitions:

  • Skin clears up

  • Sleeping better

  • Less stressed

  • Better digestion

  • Less morning sickness

That’s all happening through the science of essential oils. They’re made up of dozens to hundreds of chemical constituents that have been shown to have varying effects within the bodies. Depending on the amount of those chemical families within the essential oil impacts how it responds within the body.

Physiological vs. Psychological Approach to Oils

Most people use essential oils in one of two ways: They apply them to the skin topically (physiological) or inhale them (psychological). If you’re applying them to the skin, depending on the oil, some have something called a somatosensory effect. Take peppermint as an example. It has a menthol constituent, and when we apply that to the skin, it has a cooling sensation. This is why when we chew peppermint gum, our mouth feels cool. The same thing happens to the skin with essential oils.

Essential oils with a somatosensory effect can help release tension and have anti-inflammatory benefits. Oils that do this are lavender, juniper, and black spruce.

Many people use essential oils for stress relief, which is the pillar of aromatherapy practice. Smelling something is so helpful for our emotional health because of the anatomy of our olfactory system with our limbic system within the brain. The limbic system within our brain is our emotional command center. It contains our amygdala, which is very important for just our stress response, emotions, behaviors, and motivations. It also contains our hippocampus, which is important for just forming long-term memories. Scent plays a huge role in memory formation. It’s why you might smell something and think of your grandma.

Due to the anatomy of essential oils, it’s not possible with other senses to do this. Other senses are first processed through the thalamus of the brain and then sent to the cerebral cortex for interpretation. Our sense of smell goes straight to the limbic system, which is why our sense of smell immediately triggers an emotional response.

This has that physiological effect, too, which is why they go hand in hand. When we smell something, it influences us physiologically. It may decrease our heart rate, respiratory rate, or blood pressure. It influences our cortisol serum levels. Studies have shown that it changes brain waves, and increases deep, slow-wave sleep. They also influence just neurotransmitters such as dopamine, serotonin, and GABA, which play a huge role in anxiety.

That’s the psychological and physiological effect of essential oils. Hear more about the science of essential oils from Holly in the episode!

Disclaimer: The essential oils industry is not regulated, and everything we discuss in this interview, the benefits associated with oils, and the published medical research only apply to pure essential oils. Fragrance oils, solvent-distilled oils, and fractionally distilled oils found in grocery stores and on Amazon, and budget brands are not the oils we are talking about.

Holly’s Favorite Essential Oils:

  • Tree Oil (Black or White Spruce and Douglas Fir)

  • Lavender

  • Peppermint

  • Eucalyptus

Connect with Holly


Holly’s blog

Holly’s Courses, Books & Guides

Studies Mentioned:

Essential Oils and Memory / Cognition

Lavender is NOT a hormone disruptor

Want to try my favorite essential oils?

Order a Starter Bundle of Essentials Oils  (use code SHAREYL for 10% off your first order)

Head to www.detoxyourpits.com and use discount code WENDYKATHRYN at checkout for 10% off!

Shop all clean fragrance in my Toxin Free Shopping Guide.

Related Episodes:

Episode 2: The Fragrance Dilemma: How an Entire Industry Hijacked Your Hormones

Episode 59: Eliminating Phthalates and Paraben Can Reduce Breast Cancer Risk Markers by 73%

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