Calendula oil macerate: what are the benefits for hair?

Beyond its anti-inflammatory properties, the calendula oil macerate has demonstrated that it can reduce oxidative stress within cells and eliminate free radicals. This antioxidant activity is particularly beneficial for protecting hair follicles at the root, which are susceptible to free radical damage. Indeed, the repeated action of these unstable molecules can disrupt the melanogenesis process and accelerate the onset of grey hair. Furthermore, free radicals can interfere with the hair cycle and precipitate hair loss. The antioxidant properties of the calendula macerate could help to prevent these issues and protect the scalp and hair fibres.

The antioxidant effects of calendula stem from its content of flavonoids, polyphenols, and carotenoids, compounds capable of trapping superoxide and hydroxyl radicals, inhibiting lipid peroxidation, and increasing endogenous levels of catalase, glutathione, superoxide dismutase, and ascorbic acid. Therefore, the antioxidant activity of calendula oil macerate is twofold: it actively neutralises free radicals and boosts the body's natural production of antioxidants.

No direct study has shown that calendula macerate can prevent white hair or hair loss. It has simply been demonstrated that it can neutralise free radicals, molecules that accelerate these phenomena.

Dandruff is composed of fragments of scalp dispersed throughout the hair. This very common hair condition is primarily due to an acceleration of cellular renewal, coupled with a colonisation of the scalp by fungi of the Malassezia genus. Individual susceptibility, as well as overactivity of the sebaceous glands, are also suspected. It is possible that calendula oil macerate may have an anti-dandruff action.

Indeed, several studies have shown that this botanical extract has a antifungal activity against various fungi, such as Candida albicans, Aspergillus niger, Exophiala dermatitidis, but also Malasseria furfur. The disc diffusion method, measuring the circular inhibition zone, has been particularly used. For your information, this corresponds to an absence of fungal growth around the calendula extract placed in the centre of the Petri dish. The more sensitive the fungus is to the extract, the larger the inhibition zone. Scientists have thus measured a circular inhibition zone of 23 mm for M. furfur with an 80% calendula extract, compared to 28 mm with amoxicillin, a powerful antifungal used as a control. These results suggest that calendula might potentially help combat dandruff.

The potential effect of calendula macerate on dandruff still needs to be validated through clinical studies conducted with volunteers.

Finally, some people attribute to the oil macerate of calendula the ability to hydrate and nourish hair fibres. This idea primarily comes from the vegetable oil used as a carrier during the maceration of the flowers, as it is this which contains fatty acids with re-lipidising and film-forming properties. For instance, oleic acid contributes to the strengthening of the hydrolipidic film that coats the hair. Additionally, palmitic acid can penetrate the cuticle and join the lipid cement by inserting itself between the hair scales, thus ensuring the hair's impermeability and protection. These fatty acids are therefore particularly beneficial for dry or damaged hair.

Although no study to date has shown that calendula macerate can hydrate or nourish the hair, it can be hypothesised that the fatty acids present in its carrier oil enable it to act in this way.