Writing in Cosmetic Dermatology, researchers from Brazil analysed the use of essential oils in hair care products, notably those targeting the scalp. The research, they said, was particularly relevant given rising consumer interest and scientific research on natural, bioactive compounds.
“The main characteristics desired by consumers in the hair care category are natural ingredients, botanical ingredients, and the ‘free from’ claims such as free from salts, sulphates, silicones, parabens, and other perceived like harmful components,” the researchers wrote.
Essential oils, they said, could be classified as natural, organic and vegan and therefore aligned with these needs.
‘Great interest’ for essential oils in trichology
Review findings showed that use of essential oils in the cosmetic category had “stood out widely”, particularly for their use as active ingredients or enhancers and fragrances or aromatherapy ingredients. There was also “great interest” for use of essential oils in trichology – the medical study of the hair and scalp, the researchers said.
For hair care specifically, there was wide use of essential oils for aroma, but also increasing interest on the “skin cellular function after topical application” for scalp care, they said.
“The studies demonstrated that the oils have interesting effects, mainly, in the scalp, such as anti-hair loss, anti-inflammatory, anti-bacterial, antioxidant, anxiety-relieving and stimulant.”
“Furthermore, their lipohilic characteristic aid[s] maintaining the physiological microbiota balance of both scalp and skin,” they wrote.
Essential oils derived from plants such as lavender, thyme, peppermint, cajuput, cinnamon, clove, eucalyptus, sage and tea tree were known for their antimicrobial activities, for example, but more research was needed on the relationship between the microbiome and these ingredients. Many essential oils could also be used synergistically in formulations, the researchers said. For example: lavender, geranium and bergamot in a shampoo with a pH of 5.5-6.5 could purify the scalp, reduce irritation and control dandruff and excessive oiliness.
“The field of cosmetic dermatology is growing with the association between medical treatment of hair diseases and traditional cosmetology. Thus, essential oils have become increasingly popular in cosmetic and medicated hair products due to the growing number of reports regarding their beneficial effects on the scalp and hair.”
Beyond the scalp, essential oils like geranium, mint pepper and tangerine had also been shown to promote shine, emollience and a pleasant scent, the review found.
Essential oils are ‘complex compounds’ that warrant further study
However, the researchers said despite extensive interest around essential oils in hair care, detailed publications remained “scarce”. Further research was therefore warranted to truly understand the power essential oils could offer hair care formulations, they said.
“Because they are complex compounds, their actions on the skin, hair scalp and shaft are not yet fully understood.”
“…It is important to highlight the need for further studies on the use of essential oils in hair treatments, mainly due to the great variation in the concentration of actives due to the method of extraction, collection time, climatic conditions, geographic location, lack of standardization, low stability and reduced activity when compared to synthetic actives,” the researchers wrote.
Source: Cosmetic Dermatology
Published online ahead of print, doi: 10.1111/jocd.14286
Title: “Potential use of essential oils in cosmetic and dermatological hair products: A review”
Authors: U. Sanches Abelan et al.
