Some essential oils should only be used in the evening and require the application of sun protection in the following days. These botanical extracts are referred to as photosensitising. What do we mean by this term? What about Italian helichrysum essential oil? Continue reading to find out more.
Photosensitising: Should we avoid Italian Helichrysum essential oil in the sun?
Published on October 4, 2024, by Pauline, Chemical Engineer — 3 min of reading
Themes:
Can we expose ourselves to the sun after using Italian Helichrysum essential oil?
Some essential oils (lemon, grapefruit, bergamot...) are known to be photosensitising. Most contain furocoumarins, molecules that absorb sunlight before reacting through fluorescence and re-emitting the absorbed energy. When applied to the skin, this energy is directly transmitted to the oxygen atoms present in the epidermis, which then become free radicals capable of damaging cellular components and leading to detrimental biological effects on the skin (redness, hives, itching...). Generally, a photosensitising agent reacts under the influence of sunlight to transform into a molecule that deteriorates skin structures and weakens the epidermal barrier, making the skin more sensitive.
Obtained through the hydrodistillation of Italian helichrysum flowers, the Italian helichrysum essential oil, or everlasting essential oil, is one of the most commonly used essential oils in aromatherapy. Besides its pleasant fragrance, often described as "exotic" and "spicy", it stands out for its interesting cosmetic properties, both for the skin and hair. Indeed, the everlasting essential oil is known for its antibacterial, anti-inflammatory and protective actions. Another advantage of the Italian helichrysum essential oil : it does not contain furocoumarins and can be used morning and evening.
The essential oil of immortelle is not considered to be photosensitising.
Contrarily, a recent study conducted by LARATTA and his team demonstrated that the essential oil of Italian helichrysum possesses a Sun Protection Factor (SPF) of 6.91. This implies that it can, to some extent, block UVB rays and has some degree of photoprotective action. However, this is insufficient for the essential oil of immortelle to be considered as a sunscreen. Indeed, generally, a sunscreen begins to be considered effective when its SPF is 15 or above. Furthermore, the essential oil of Italian helichrysum is not officially recognised and listed as a sunscreen by European regulations.
Note : The use of immortelle essential oil in the event of sun exposure is not pointless. Thanks to its antioxidant properties, it can protect the skin from oxidative stress and help it fight against premature skin ageing caused by free radicals.
Sources
APPENDINO G. & al. Helichrysum italicum: The dormant titan of Mediterranean herbal medicine. Herbalgram (2015).
THOMAS A. & et al. Photosensitisation Reactions of Biomolecules: Definition, Targets and Mechanisms. Photochemistry and Photobiology (2021).
LARATTA B. & al. Determination of Antioxidant Activity and Sun Protection Factor of Commercial Essential Oils. Biology and Life Sciences Forum (2021).
