Seaweed Extract
Reviewed by Daisy · Last updated 18 Aug 2026
Also known as: Undaria pinnatifida (algae) extract, brown algae
A type of brown algae (seaweed) that is also edible | Rich source of nutrients that benefit skin when applied topically
Addresses
EWG Safety Score
What Is Seaweed Extract?
Undaria pinnatifida, also known as brown algae, is a type of seaweed that’s also edible. As with most seaweeds, it’s a rich source of nutrients, and those benefit skin when applied topically. Among the benefits from applying brown algae to skin are antioxidant from its polyphenols, hydration from its polysaccharides, and soothing, thanks to a compound known as fucoidan.
In vitro (test tube) research has shown this type of algae plays a disruptive role in the pathway melanin (skin pigment) takes to make it to skin’s surface. In theory, topical use may keep discolorations at bay.
Some research indicates brown algae has more antioxidants than red or green algae, but topically, all of them can thwart the cascade of damage common airborne pollutants can trigger on skin.
Clinical Evidence & References
Published Research
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Marine Drugs, November 2018, ePublication [URL_NOT_FOUND]
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Cosmetics, February 2018, ePublication; and April 2015, pages 66-81 [URL_NOT_FOUND]
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Oncotarget, March 2017, pages 17,887-17,896 [URL_NOT_FOUND]
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Interdisciplinary Toxicology, May 2014, pages 89-92 [URL_NOT_FOUND]
Frequently Asked Questions
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