This liquid extract of Ulva (Ulva lactuca) seaweeds is obtained by filtration, after a long maceration and stirring of the seaweed in a mixture of glycerin and water.

Ulva lactuca is a thin flat green alga growing from a discoid holdfast. The margin is somewhat ruffled and often torn. It may reach 18 centimetres (7.1 in) or more in length, though generally much less, and up to 30 centimetres (12 in) across. The membrane is two cells thick, soft and translucent, and grows attached, without a stipe, to rocks or other algae by a small disc-shaped holdfast.

Green to dark green in colour, this species in the Chlorophyta is formed of two layers of cells irregularly arranged, as seen in cross-section. The chloroplast is cup-shaped in some references but as a parietal plate in others with one to three pyrenoids. There are other species of Ulva that are similar and not always easy to differentiate.

The Ulva (Sea Lettuce) Glycerin extract is used for making revitalizing and moisturizing cosmetic products. The main characteristic of this algae consists of a high value in amino acids and proteins. It also contains a high value of carbohydrates. It is perfectly adapted to skincare products like firming or contouring cream.