The properties of true lavender essential oil on hair.

The essential oil of true lavender (Lavandula angustifolia), also known as fine lavender, is extracted from the flowering tops. It grows between 600 and 1,400 metres above sea level, in the sunny valleys or mountains of Provence, and certain regions of Spain and Italy.

The flowering tops of true lavender are used in the production of essential oil through the process of steam distillation (hydrodistillation). It is distinguished from lavandin, a hybrid between true lavender and spike lavender, by its low yield.

When mixed with other ingredients, true lavender essential oil provides softness to the hair and soothes the scalp. It is therefore included in the formulation of several hair care products such as lotions, shampoos, or masks.

The essential oil of true lavender offers various benefits for the scalp and is suitable for all hair types. Its main actions are summarised here.

• The essential oil of true lavender soothes the scalp.

  Irritations and feelings of discomfort in the scalp can be reduced thanks to the soothing properties of true lavender essential oil. Its sedative and calming actions complement these properties, ensuring the well-being of the scalp. The linalool and linalyl acetate that make up this oil are indeed capable of inhibiting certain nociceptors, receptors responsible for the transmission of pain in the body. This reduces itching, which also limits the flaking of the scalp and the formation of dandruff. Furthermore, the antimicrobial properties of true lavender essential oil allow it to combat bacteria and fungi, thereby sanitising the scalp.

• It acts against certain parasites.

  The presence of linalool and terpinen-4-ol in true lavender essential oil makes it an effective repellent against parasites of the scalp and hair, such as lice. Indeed, these molecules inhibit acetylcholinesterase, an enzyme found in these parasites that leads to the degradation of their acetylcholine neurotransmitter. This mechanism is the cause of the neurotoxicity of true lavender essential oil for lice. To combat these, apply a drop of pure essential oil or diluted in a vegetable oil behind each ear and massage. This treatment can be done as a preventive or corrective action.

• This essential oil mitigates the effects of hair loss.

  Indeed, a study has shown that its use in synergy with essential oils of thyme linalool, rosemary, and Atlas cedar would help to alleviate thealopecia. A comparison of hair growth was carried out over 12 weeks between two groups of individuals suffering from alopecia: one applied the mixture of essential oils to the scalp and the other used a placebo. The results highlighted a significantly greater hair growth in those using the mixture of essential oils. However, the mechanism behind this hair regrowth has not yet been elucidated.

• It exhibits purifying properties.

  The essential oil of true lavender is perfectly suited to scalps prone to oiliness. The active ingredients in its composition (mainly linalool and linalyl acetate) give it an absorbent action, thus limiting the negative effects of hyperseborrhea. The scalp and hair appear less oily. A decrease in sebum levels has been particularly observed when using a combination of true lavender essential oils, tea tree and eucalyptus.

It is also suggested that true lavender essential oil may promote hair growth by stimulating microcirculation of the blood, but these properties remain controversial.

The essential oil of true lavender is suitable for all scalp types and is very gentle. It is one of the most recognised in aromatherapy: it can be used undiluted and does not cause skin irritation. However, its use is not recommended for pregnant and breastfeeding women, and young children. To avoid any risk of overdose, it is advised for people with sensitive skin to dilute it in a vegetable oil.

It is also important to note that true lavender essential oil contains potentially allergenic biochemical compounds, such as geraniol, linalool, coumarin, and limonene. Therefore, it is recommended to conduct a tolerance test before incorporating it into a hair care product.

To test the true lavender essential oil, apply two drops in the crook of your elbow and wait for at least 24 hours. If no adverse reaction is observed, it can be used on the scalp or skin.

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• ALTMAN P. M. & co. An ex vivo, assessor blind, randomised, parallel group, comparative efficacy trial of the ovicidal activity of three pediculicides after a single application - melaleuca oil and lavender oil, eucalyptus oil and lemon tea tree oil, and a "suffocation" pediculicide. BMC Dermatology (2011).

• WALL R. & al. Management of the chewing louse Bovicola (Werneckiella) ocellatus in donkeys, utilising essential oils. Medical and veterinary entomology (2013).

• HOLLINGER J. C. & co. The application of natural components in the treatment of hair loss conditions, focusing on central centrifugal cicatricial alopecia: a comprehensive review. Journal of Clinical and Aesthetic Dermatology (2020).

• LADERMANN J. & al. Safety and efficacy of combined essential oils for the skin barrier properties: In vitro, ex vivo and clinical studies. International Journal of Cosmetic Science (2022).