Red Seaweed Extract (Betaphycus)

Evidence by route

About this ingredient

Red seaweed extract Betaphycus gelatinum (Betaphycus Gelatinum Extract) is a marine extract, a source of carrageenan-like polysaccharides: sulphated polygalactans and iota-carrageenan. Mechanism. On skin it works as a film-former and humectant. Sulphated polysaccharides bind water molecules and build a thin gel film that holds moisture in the stratum corneum. In a formula it also acts as a thickener and emulsion stabiliser. Where applied. Sheet masks, hydrating serums, marine-extract creams, K-beauty lines. Concentration 0.1–2%. In Spain found in niche natural and Asian cosmetics; less common in dermocosmetics. Evidence base. Few direct clinical RCTs on topical Betaphycus extract. Indirect evidence via carrageenans, with described antioxidant and humectant activity in vitro (Yan 2016). Safety. Hypoallergenic, non-comedogenic, non-irritating. No direct CIR monograph, but the marine red algae family and their polysaccharides at cosmetic concentrations are considered safe. Contact allergies are described as isolated cases in patients with seafood allergies. In pregnancy – safe topically. No direct lactation data; the risk is purely theoretical. Realistic assessment. A 'marine cosmetics' marketing ingredient with a pleasant film-forming and humectant action. No standalone anti-age effect. A good component of hydrating formulas, but not a pick for a lead active.

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