What is kelp extract?
Macrocystis pyrifera, or giant kelp, is a large brown seaweed that grows in cool coastal waters. Its extracts contain polysaccharides such as alginate and fucoidan, plus minerals from seawater.
What it does for skin
Seaweed polysaccharides act as humectants that help skin hold moisture, and they give serums body. Some brown-seaweed compounds, notably fucoidan, show antioxidant activity in laboratory tests.
What the research shows
A 2018 review of seaweed ingredients for cosmetics describes brown-algae alginate as a thickener and stabilizer, seaweed polysaccharides as moisture-retaining humectants, and fucoidan as one of the strongest antioxidants among the seaweed polysaccharides it compared.
Most of that evidence comes from laboratory work, and the review does not single out Macrocystis, so claims for giant kelp specifically are limited.
In DermaGlass®
Kelp extract is listed 16th of 21 ingredients. With red seaweed (Chondrus crispus) it is one of the two marine extracts behind the “marine bio-extract” in DermaGlass®.
See the full DermaGlass® ingredient list or how to use the mask.
Safety
Seaweed extracts are widely used in skincare and generally well tolerated.
Questions
What does kelp do in skincare?
Its polysaccharides help skin hold moisture and give the serum a smooth, cushioned feel.
Is kelp extract the same as seaweed extract?
Kelp is one type of seaweed — a brown seaweed. “Seaweed extract” on a label can mean many different species.
Sources
General information, not medical advice. Read our terms.