The cucumber (Cucumis sativus) is a member of the gourd family, Cucurbitaceae, which also includes pumpkin, zucchini, watermelon, and squash. Most types of cucumber are composed of 95% water. Despite this high concentration of water, the cucumber contains a wide variety of beneficial nutrients, such as vitamins, minerals, amino acids, phytosterols, phenolic acids, fatty acids, and cucurbitacins. There are several antioxidants naturally found in cucumber, for instance, ascorbic acid, beta carotene, and caffeic acid. Cucumbers also contain antioxidant flavonoids, such as quercetin, apigenin, luteolin, and kaempferol. Antioxidants limit oxidative damage caused by free radicals, the unstable molecules that contribute to the formation of premature wrinkles and fine lines on the skin.

Cucumber extract imparts anti-inflammatory effects when applied to the skin, as well as effectively hydrates and conditions the skin due to its rich composition of polysaccharides. Polysaccharides are good water-binding agents. After topical application, they create a gel-like layer on skin that acts as a barrier to attract and keep moisture in. Lastly, cucumber extract contains fragrant components that are not sensitizing to skin, so it can be used to enhance the natural scent of a cosmetic product without issue.