Is camelina oil comedogenic?

If a vegetable oil promotes the formation of comedones (spots, blackheads, etc), particularly by blocking the pores through hyperkeratinisation or by overproduction of sebum, it is described as "comedogenic".

The comedogenicity index refers to the ranking of cosmetic ingredients in relation to their comedogenic potential. Historically, this classification was established by MORRIS and his team in 1983, based on studies conducted on rabbit ears, taking into account the appearance of follicles, the onset of hyperkeratosis, and the manifestation of inflammation after use.

However, these criteria are no longer relevant. Criticisms have been raised regarding their application in humans, particularly on the basis that rabbit ears differ significantly from human skin, among other things due to the difference in pore size.

To date, a reassessment of this classification has been carried out. Vegetable oils are measured on a scale ranging from 0 (non-comedogenic) to 5 (highly comedogenic). Various characteristics are taken into account to determine this index.

• Oxidation Level : indeed, a non-comedogenic oil that has undergone oxidation (rancidity) becomes comedogenic. Due to the significant presence of fatty acids with numerous double bonds (polyunsaturated fatty acids), an oil may tend to oxidise quickly. An oil containing few fatty acids with double bonds and a high concentration of antioxidants will, on the other hand, be "protected" from oxidative degradation.

• Thickness and texture: the thicker and more viscous an oil is, the less it will be able to penetrate the skin. It will then tend to clog the pores and thus cause the appearance of comedones.

Indices 0 and 1 are recommended for individuals with oily skin, as well as those prone to acne. For normal to combination skin, an index between 0 and 3 is preferred. Finally, dry skin has no restrictions. It is possible to use all oils with an index between 0 and 5.

Referring to this classification, camelina oil falls under the category of non-comedogenic vegetable oils, making it appealing for blemished skin. It notably contains a significant amount of antioxidants (up to 100 mg of tocopherols) compared to other vegetable oils. These compounds then serve to stabilise the oil and slow down its oxidation by light, heat or oxygen.

It should be noted that camelina oil can become comedogenic through oxidation, due to the presence of numerous polyunsaturated fatty acids. Therefore, it should be stored in a cool place, protected from oxygen and light.

Furthermore, camelina oil is quite fluid and light, and is quickly absorbed by the skin without leaving a greasy film. Thus, it is less likely to clog the skin's pores. However, it should be kept in mind that the term "comedogenic" is not an exact science.

• Comedogenicity can occur with oxidation, the classification is not definitive.

• What is "comedogenic" for one person may not necessarily be so for another.

• The fact that an ingredient is considered comedogenic does not automatically mean that the product containing it is also comedogenic. This will depend on its concentration in the product.

• MORRIS W. E. & al. Use of the rabbit ear model in evaluating the comedogenic potential of cosmetic ingredients. Journal of the Society of Cosmetic Chemists (1983).

• STAVRIANEAS N. G. & al. Comedogenicity of cosmetics: a review. Journal of the European Academy of Dermatology and Venereology (1996).

• DINARDO J. & al. A re-evaluation of the comedogenicity concept. Journal of the American Academy of Dermatology (2006).

• Thèse de Sonia LEPELTIER. Étude ethnobotanique de Camelina sativa (L.) Crantz (2021).