What is it?
The oil obtained from the seeds of watermelon, Citrullus lanatus. It is rich in linoleic acid, an omega-6 polyunsaturated fatty acid, and in parts of West Africa and the Middle East it is produced locally as an edible oil. In cosmetics and personal care products it works as an emollient that softens and conditions the skin, in products such as facial oils, creams and lotions.
Key information
- The CIR Expert Panel concluded that watermelon seed oil is safe in the present practices of use and concentration in cosmetics.
- It is a high-linoleic oil: linoleic acid made up 55 to 65 percent in the data the Panel reviewed.
- A facial oil containing 2 percent watermelon seed oil caused no irritation or allergic reactions in a repeated patch test on 105 people.
More information
Watermelon is grown mainly for its sweet flesh, but in sub-Saharan Africa and dry regions of India some crops are grown for their seeds, which are rich in protein and oil. The CIR report lists the oil as 55 to 65 percent linoleic acid, with oleic, palmitic and stearic acids making up most of the rest, and a 2018 study of Indian seed varieties found 44 to 55 percent linoleic acid. Polyunsaturated fats like linoleic acid are especially prone to oxidation, although the peroxide values measured in that study were within Codex standards for vegetable oils.
The Cosmetic Ingredient Review (CIR) Expert Panel included Citrullus Lanatus (Watermelon) Seed Oil in its assessment of 244 plant-derived fatty acid oils and concluded that it is safe in the present practices of use and concentration. It was little used at the time, with one product at 2 percent in the 2010 data. In a repeated insult patch test on 105 people, a facial oil containing 2 percent watermelon seed oil was not irritating or sensitizing. The Panel also noted that people with a food allergy rarely react to refined oil from the same plant, because the proteins that cause allergy do not carry over into refined oil.
As with other oils rich in polyunsaturated fat, keep products away from heat and light and discard any that smell rancid. On labels, look for Citrullus Lanatus Seed Oil; the older name Citrullus Vulgaris Seed Oil refers to the same plant.
Sources: Cosmetic Ingredient Review: Plant-derived fatty acid oils, final report for Expert Panel review (March 2011); Journal of Food Science and Technology (2018): Fatty acid methyl esters and oxidative stability of seed-purpose watermelon genotypes
