From money-making side hustles to personal care products, the art of Aromatherapy has become a household practice without many even realizing they’re using it — But how safe are essential oils? And what’s all the hype about? Do they even really work?

Often perceived as nothing more than smelly fragrance oils with hefty price tags, essential oils are one of the most underrated, yet overused holistic modalities available, and today I’m going to breakdown the essentials of essential oils, their safety and a few of my favourite oils for many common issues.

Aromatherapy and essential oils can be extremely effective complementary additions to holistic therapies and treatments.

HOWEVER, the definition of Aromatherapy today has changed significantly from its latin roots, which is, in essence, a therapy that utilizes aroma to help to restore the body to optimal health and well-being.

We have begun to diffuse essential oils all day long based solely on scent preference and many of us tend to be guided moreso by principles of consumerism, believing that “more is more” when it comes to the use of essential oils.

In addition to a “more is more” attitude, many people have found themselves in a paradoxical relationship to Aromatherapy where they enjoy it and use it excessively, with little to no understanding of the true, scientific components and chemical constituents of the oils, and/or the difference that quality makes in not only their effects but also their safety.

So, in today’s post, we are going to discuss how Aromatherapy works, the uses of essential oils, and how to use essential oils safely.

Aromatherapy

Commonly defined as: the use of aromatic plant extracts and essential oils in massage or baths, but I prefer the definition of essential oils as explained in this study as I feel it truly outlines the holistic nature of essential oils and their chemical constituents:

“Essential oils are concentrated natural products with strong smells that are produced by aromatic plants as secondary metabolites. These oils are present as variable mixtures of primarily terpenoids, especially monoterpenes (C10) and sesquiterpenes (C15), although diterpenes (C20) may also be present. A variety of other molecules also occur, such as acids, alcohols, aldehydes, aliphatic hydrocarbons, acyclic esters or lactones; rare nitrogen- and sulphur-containing compounds; coumarins; and homologues of phenylpropanoids. EOs are liquid, volatile, limpid and coloured and are soluble in lipids and organic solvents that have a lower density than water. They can be present in all plant organs, including buds, flowers, leave, seeds, twigs, stems, flowers, fruits, roots, wood or bark, but are generally stored by the plant in secretory cells, cavities, canals, glandular trichomes or epidermic cells” Source

Now that we have a concrete understanding of what Aromatherapy and essential oils are, we must take a closer look at how Aromatherapy and essential oils work.

Olfaction

What Is Olfaction?

the action or capacity of smelling; the sense of smell

How Does Olfaction Work?

Olfaction: Effects on The Brain

Each olfactory neuron has one odor receptor. Microscopic molecules released by substances around us—whether it’s coffee brewing or pine trees in a forest—stimulate these receptors. Once the neurons detect the molecules, they send messages to your brain, which identifies the smell (source)

Limbic system

The olfactory bulb that recognizes smells is part of the brain’s Limbic System — the area associated with emotion, memory and feeling, thus the physiological process of smell is strongly linked to our memories and emotions. 

All gray matter areas that receive output from the olfactory bulb are called olfactory cortex and the olfactory cortex projects into the hypothalamus which is believed to use olfaction as a key component in the physiological processes of feeding, reproduction and autonomic reflexes.

Nervous system

The olfactory cortex mentioned above, also projects into the cortical amygdala which has a direct effect on the Basolateral Amygdala (the part of the brain responsible for our fight, flight and freeze response), thus, it’s important to consider the potential impact (positive and negative) on the health and function of the nervous system, as our olfactory system plays an integral role in our sensory perception of our surroundings.

Pharmacological Effects

Each oil is absorbed into the blood stream through the olfactory bulb and/or dermis, as the odour molecules themselves bind to receptors in the olfactory bulb. In addition to odour molecules, essential oils and their volatile components enter the bloodstream quite efficiently when applied topically to the epidermis. Their mode of action is such that they have the ability to disintegrate the intercellular lipid structure between corneocytes and stratum corneum to enhance dermal penetration of not only themselves, but additional molecules that they are paired with.

Phytochemicals in Essential Oils and Their Effects (New World Library, 2016)

Aldehydes

Antibacterial, antiviral, antifungal, immunostimulating, anti-inflammatory, calming, relaxing, sedative, nerve tonic, uplifting

Examples:

• Lemongrass
• Cinnamon
• Melissa

Coumarins

Calming, sedative, hypotensive, antispasmodic, can cause photosensitivity

Examples:

• Cinnamon
• Peppermint
• Lavender

Esters

Antifungal, analgesic, antispasmodic, anti-inflammatory, sedative, calming, relaxing, hypotensive, balancing

Examples:

• Roman Chamomile
• Clary Sage
• Lavender
• Helichrysum
• Bergamot
• Jasmine

Ethers

Anti-infectious, antispasmodic, sedative, analgesic, balancing

Examples:

• Anise
• Basil
• Cinnamon
• Fennel

Ketones

Antibacterial, antiviral, antifungal, antiparasitic, wound healing, mucolytic, expectorant, decongestant, immunostimulant, analgesic

Examples:

• Frankincense
• Peppermint
• Rosemary
• Sage
• Spearmint

Lactones

Calming, relaxing, fever-reducing, mucolytic, expectorant, antiparasitic, immunostimulant

Examples:

• Bergamot
• Lemon
• Sweet Orange
• Lime
• Grapefruit

Monoterpenes

Antibacterial, antiviral, antiseptic, analgesic, respiratory decongestant, expectorant, immunostimulant

Examples:

• Rosemary
• Melaleuca
• Marjoram
• Fennel
• Wild Orange
• Lemon
• Lime
• Frankincense
• Cypress
• Bergamot

Monoterpenols

Antibacterial, antifungal, antiseptic, immunostimulant, stimulant, balancing

Examples:

• Peppermint
• Lavender
• Clary Sage
• Palmarosa
• Spike Lavender
• Tea Tree
• Petitgrain

Oxides

Antifungal, respiratory decongestant, expectorant, analgesic, antispasmodic

Examples:

• Eucalyptus Globulus
• Fragonia
• Spike Lavender

Phenols

Antibacterial, antiviral, antifungal, antiparasitic, analgesic, antispasmodic, immunostimulant, can be irritant to mucous membrane and skin

Examples:

• Clove Bud
• Oregano
• Cinnamon Leaf
• Holy Basil

Sesquiterpenes

Antibacterial, antiseptic, calming, anti-inflammatory, stimulant, hypotensive, blood and lymph decongestant, antiallergenic

Examples:

• Ginger
• Cedarwood
• Melissa
• Vetiver
• Patchouli
• Ylang Ylang

Sesquiterpenols

Anti-infectious, anti-inflammatory, vascular tonic, immune tonic, stimulant, balancing

Examples:

• Carrot Seed
• Cedarwood
• German Chamomile
• Ginger
• Patchouli
• Sandalwood
• Vetiver

Memory/Association

Similar to the function of our acquired immune system, each odour detected by the olfactory system is stored away as a memory, along with the physical/mental/emotional memory from that experience, and, if the memory leads to certain hormonal changes such as a change in blood pressure or body temperature, the same hormonal changes will occur when the odour is smelled again.

This is extremely important both for the positive potential associated with being able to recall past memories and events and work through traumas or recall memories (for example, active recall during tests and exams), but it is also imperative that we understand the potential effects on the psyche when using essential oils around others whose emotional history we do not know, both in the clinic and personal settings to avoid initiating any form of negative or trauma-based response.

Phytotherapy

Many people have first-hand experience with herbalism and certain plant-derived therapies to treat a range of ailments, but how, exactly, do these therapies work?

It is, in fact, the information contained within the plants that is responsible for the physiological benefits experienced with the use of herbal medicine and other types of phytotherapy. Whether you have used oil of oregano to cure a cold, drank an herbal tea, used cabbage leaves to soothe engorged breasts or sprained limbs, taken fenugreek to help with milk supply, milk thistle to aid in liver detox or even taken larger quantities of raw garlic to help overcome an infection, you have harnessed the intrinsic protective and proliferative qualities of the plants themselves to enhance your own well-being. 

While many still support the argument that the effects of traditional medicine are simply placebo effects, when we begin to understand the chemical constituents of plant material and the ways in which these plant species have adapted for survival, we begin to see that these effects are deeply rooted in science, as opposed to folklore.

In addition to that, it’s important to remember that every pharmaceutical product available has a phytotherapeutic muse — a plant or biological species that has inspired its synthetic production in an effort to replicate its ability to heal, treat or preserve life.

And so, with that in mind, we must not forget Aromatherapy and essential oils with respect to phytotherapy and not only its efficacy, but also its potency and, most importantly, its safety, as much like the olfactory system is often the overlooked sensory process, so too is the medicinal impacts and potential ramifications of Aromatherapy and essential oils. 

To clarify, I am pro-essential oils. I find them extremely useful in my practice and I feel that the olfactory system is an underrated aspect of physiological healing. However, I believe that education is key when using any form of therapeutic or pharmaceutical intervention — you wouldn’t use a pharmaceutical on or around your child or pet without first knowing the safety data, and the same discernment should be used when considering essential oils.

In fact, in order to demonstrate the gravity and clinical effectiveness of essential oils and their potential, here is  a link to this study that shows thyme oil and its efficacy against MRSA infections — an antibiotic resistant strain of bacteria that has proven too challenging for many of Western Medicine’s pharmaceutical interventions.

So, now that we have covered the most important part of essential oil safety – truly understanding what they are and how they work, let’s get into the myriad of ways essential oils can be used, and their health benefits.

Aromatherapy: Uses and Indications

Essential Oils for Stress Management

Essential Oils For Chemical Stress

By now, you know that my main concern with the health of the collective is our chronic exposure to chemical stress – in the air we breathe, food we eat, water we drink and shower in, etc. Some of my favourite essential oils for chemical stress are:

• Lavender
• Clary Sage
• Geranium
• Grapefruit
• Rosemary
• Lemon

Essential Oils For Physical Stress

• Bergamot
• Chamomile
• Lavender

Essential Oils For Mental Stress

• Lavender
• Grapefruit
• Sandalwood
• Basil
• Patchouli

Essential Oils For Emotional Stress

• Vetiver
• Sandalwood
• Rose Otto
• Bergamot
• Ylang Ylang

Essential Oils For Focus

• Basil
• Bergamot
• Grapefruit
• Lemon
• Rosemary
• Peppermint
• Eucalyptus Lemon

Essential Oils For Calm

• Bergamot
• Lavender
• Marjoram
• Mandarin
• Petitgrain

Essential Oils For Depression

• Mandarin
• Chamomile
• Lemon
• Bergamot
• Grapefruit
• Rose Otto
• Neroli
• Geranium
• Sandalwood
• Clary Sage
• Lavender
• Frankincense
• Cardamom

Essential Oils For Lymphatic Drainage

• Juniper
• Grapefruit
• Cypress
• Sweet Orange
• Cedarwood

Essential Oils For Pain Relief and Management

• Roman Chamomile
• Geranium
• Lavender
• Peppermint
• Rosemary
• Ginger
• Cypress

Essential Oils For Sleep

• Vetiver
• Lavender
• Bergamot
• Roman Chamomile
• Frankincense
• Geranium
• Mandarin
• Melissa
• Neroli
• Valerian

Anti-Microbial/Anti-Viral Essential Oils

• Eucalyptus Radiata & Globulus
• Frankincense
• Ginger
• Tea Tree
• Thyme Linalol
• Rosemary
• Lavender
• Manuka
• Melissa
• Lemongrass

Anti-Inflammatory Essential Oils

• Lavender
• Chamomile
• Frankincense

Essential Oil Safety: A General Overview

Essential Oils Not For Use on Hypersensitive Skin

• Garlic

Essential Oils To Be Used With Caution on Hypersensitive Skin

• Anise
• Citronella
• Clove Bud
• Clove Leaf
• Clove Stem
• Lemon Eucalyptus
• Melissa
• Oregano
• Thyme

DO NOT USE The Following Essential Oils on Mucous Membranes (ie. Do not use in baths)

• Basil
• Cinnamon Leaf
• Fennel
• Lemongrass
• Lemon
• Lemon Verbena
• Melissa
• Bitter Orange
• Peppermint
• Thyme (red and wild)

Essential Oils – Use With Caution on Mucous Membranes

• Caraway
• Clove Bud
• Peppermint
• Spearmint

Essential Oils Contraindicated For Epilepsy

• Camphor
• Peppermint
• Rosemary
• Sage
• Yarrow
• Fennel
• Wormwood

Essential Oils NOT TO BE USED With Fever

• Camphor
• Spike Lavender
• Rosemary
• Spanish Sage
• Yarrow

Essential Oils Contraindicated for High Blood Pressure

• Rosemary
• Sage

Essential Oils Contraindicated for Liver and Kidney Disease

• Parsley Leaf
• Parsley Seed
• Indian Dill

Essential Oils Contraindicated for Pregnancy

• Basil
• Atlas Cedarwood
• Clary Sage
• Cypress
• Jasmine
• Juniper Berry
• Sweet Marjoram
• Peppermint
• Rosemary
• Thyme
• Oregano
• Clove

Essential Oils That May Cause Photosensitivity

• Bergamot
• Grapefruit
• Lemon
• Lime
• Bitter Orange

So there you have it. The basics of Aromatherapy and essential oils, including general safety guidelines and chemical components, a brief overview of the science behind essential oils and their effects on the brain and body and a few of my favourite essential oils and their uses. While this is certainly not an exhaustive compilation, I hope that it helps provide some clarity when using and choosing essential oils in your daily life.

If you’d like more information on essential oils or if you’d like to incorporate essential oils safely into your healthy lifestyle regime and you’d like some guidance, I’d be happy to help.

In the meantime, I’m curious, what is your favourite essential oil?

Mine is lime. Hands down.
To me, there is no greater smell than that of fresh squeezed lime juice or lime essential oil in the air.