The European Pharmacopoeia defines essential oil as a fragrant product, often with a complex composition, obtained from a precisely identified plant material by steam distillation, dry distillation or a mechanical process without heating. Essential oils, available in pharmacies, allow for personalised advice and an interdisciplinary approach to care. In practice, topical application is often preferred because it is simple, effective and limits general side effects. By adjusting the dosage and frequency of administration, the therapist can offer preventive or curative treatments.
What is an essential oil?
Within the plant, the essence remains scarce, generally between 1 and 3% of the total mass. However, this aromatic fraction plays a major role. It contributes to the plant’s defence and supports its “immunity”, acting as the first line of defence against external aggressions.
How can the physical properties of essential oils be described?
Essential oils are liquid at room temperature, which makes them easy to use. They appear oily but do not leave a greasy film because they are volatile. Their density, often lower than that of water, causes them to float on the surface. They are insoluble in water but dissolve in alcohol, fatty substances and certain solvents, depending on their chemical composition.
What are the chemical and therapeutic properties of essential oils?
Each essential oil contains hundreds of molecules, the rarest of which also contribute to the overall effect. The aromatogram illustrates the link between biochemical structure and efficacy, highlighting the synergy between the compounds. In general, essential oils have anti-infectious (antibacterial, antiviral, antifungal) properties. They also have anti-inflammatory, antispasmodic, analgesic, digestive, healing, endocrine-regulating and immunoregulatory properties, making them versatile tools for health.
How do essential oils affect the nervous system and emotions?
Aromatic molecules stimulate the olfactory receptors and send signals to the nerve centres. They can thus modulate behaviour and emotional state. This dual action, both physico-chemical and neuro-emotional, explains the central role of essential oils in aromatherapy, natural medicine and perfumery.
Are there any essential oils that are only available in pharmacies?
Certain essential oils are only available in pharmacies due to their composition and potential risks. Their use is governed by specific regulations. Law No. 84-534 of 30 June 1984 and the decree of 23 June 1986 initially restricted the sale of eight essential oils. The decree of 3 August 2007 extended this list to 15 items. Most of them are rich in thujone or pinocamphone.
| Common name | Scientific name |
|---|---|
| Grand wormwood | Artemisia absinthium L. |
| Small wormwood | Artemisia pontica L. |
| Common mugwort | Artemisia vulgaris L. |
| White mugwort | Artemisia herba alba Asso |
| Tree-like mugwort | Artemisia arborescens L. |
| Western red cedar | Thuja occidentalis L. |
| Korean cedar | Thuja koreensis Nakai |
| Hyssop | Hyssopus officinalis L. |
| Salvia officinalis | Salvia officinalis L. |
| Tansy | Tanacetum vulgare L. |
| Giant thuja | Thuja plicata Donn ex D. Don. |
| Sassafras | Sassafras albidum (Nutt.) Nees |
| Sabine | Juniperus sabina L. |
| Rue | Ruta graveolens L. |
| Wormwood | Chenopodium ambrosioides L. |
| Anthelmintic goosefoot | Chenopodium anthelminticum L. |
| Mustard | Brassica juncea (L.) |
How should essential oils be administered and what dosage should be chosen?
Essential oils can be administered in several ways, each with its own rules. The most common method is through the skin, which benefits from the good affinity of aromatic molecules with the skin. However, it requires dilution in a vegetable oil to limit irritation.
Diffusion into the atmosphere and inhalation allow the oils to act through the respiratory tract, which is useful for creating a pleasant atmosphere and promoting well-being, provided that moderate diffusion times and contraindications are respected. Aromatic baths combine the benefits of water and essential oils, which must always be mixed with a dispersing agent to avoid direct contact with the skin.
Oral administration, which is more powerful and faster-acting, is reserved for low doses and specific indications. It requires great caution, especially in pregnant women and children. In some cases, rectal administration in the form of suppositories may be justified, but only under professional supervision. Regardless of the route of administration, efficacy and safety depend on strict rules regarding dosage, duration and monitoring.
Conclusion
Essential oils are plant extracts with a high chemical richness and strong biological activity. This concentration explains their interest in aromatherapy, but also the need for sensible, supervised and informed use. By understanding their properties, methods of administration and associated precautions, it is possible to enjoy their benefits while limiting the risks, in a safe and responsible approach to natural health.
Sources
- https://ansm.sante.fr/qui-sommes-nous/notre-perimetre/les-medicaments/p/medicaments-a-base-de-plantes-et-huiles-essentielles#:~:text=An essential oil is the,definition of the European Pharmacopoeia).
- https://dumas.ccsd.cnrs.fr/dumas-01719690/document
- https://www.anses.fr/fr/system/files/NUT2018SA0096.pdf
- https://pranarom.fr/pages/distillation-des-huiles-essentielles
- https://www.tisserandinstitute.org/essential-oils-in-hospitals/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5206475/
- http://www.nccih.nih.gov/
FAQ – For optimal use of essential oils
What is an essential oil according to the European Pharmacopoeia?
The European Pharmacopoeia defines essential oil as a fragrant product, generally of complex composition, obtained from a botanically defined raw material by steam distillation, dry distillation or an appropriate mechanical process without heating.
How are essential oils obtained in aromatherapy?
Essential oils are mainly obtained by steam distillation of aromatic plants, or by mechanical expression for citrus zest, in order to concentrate the volatile compounds responsible for their aromatic and therapeutic properties.
What are the main methods of administering essential oils?
Essential oils can be used on the skin, in atmospheric diffusion, in aromatic baths, and more rarely by oral or rectal administration, always in appropriate dosages, with an appropriate carrier and the advice of a healthcare professional.
Certain essential oils are contraindicated for pregnant or breastfeeding women, children, people with epilepsy, asthma or the elderly, particularly those rich in ketones, phenols or monoterpenes, which requires medical advice before any risky use.
Which essential oils are only available from pharmacies?
Several essential oils rich in thujone or pinocamphone, such as certain types of mugwort, sage, hyssop, thuja and tansy, are subject to specific regulations and can only be dispensed in pharmacies, sometimes on medical prescription.
