Gigartina Stellata Extract
Red algae extract from Gigartina stellata. The manufacturer claims moisturising, protective, and 'antiviral' effects on skin. A close relative is Chondrus Crispus (Irish moss), which has its own DB card. Topical evidence is limited; claimed effects are extrapolated from in vitro data on carrageenans, the polysaccharides of these algae.
Evidence by route
Topical application
Topical clinical studies are essentially absent. Antioxidant and moisturising activity is confirmed only in laboratory models; clinical extrapolation to skincare benefit is not established.
- Wijesekara I et al. Carbohydr Polym. 2011;84(1):14-21. DOI 10.1016/j.carbpol.2010.10.062
How to read tiers A–F
- DNo data, or very weak or conflicting data
Tolerability and safety
- Irritation potential
- Low
- Allergen risk
- Low
- Pregnancy
- Safe
- Suitable for
- Normal, Dry, Combination, Sensitive
About this ingredient
Gigartina Stellata Extract is derived from the red marine alga Gigartina stellata (Mastocarpus stellatus), which grows on rocky shores of the North Atlantic (Ireland, Scotland, Brittany, northern Spain). Rich in carrageenans – sulfated polysaccharides that form gels in aqueous media – along with iodine, amino acids, minerals (magnesium, calcium, zinc, copper), and B vitamins. In cosmetics it is used at 0.5–5% as a humectant, film-former, and mild thickener. Effects: binding water on the skin surface and in the upper epidermis, forming a thin protective film, reducing transepidermal water loss, and mild antioxidant and anti-inflammatory activity. In vitro data (Cosmetics, 2019) show 5-alpha-reductase inhibition at higher concentrations, which justifies inclusion in scalp products for oily seborrheic tendency. Carrageenans also show antiviral activity against HPV and herpes simplex when applied topically, though cosmetic formulations do not reach therapeutic concentrations. Safe for all skin types, non-comedogenic, and does not cause contact dermatitis. Suitable in pregnancy and breastfeeding. Compatible with niacinamide, hyaluronic acid, peptides, and ceramides. Not recommended in known iodine or seafood allergy – cross-reaction is possible.
Frequently asked questions
Is Gigartina Stellata Extract safe during pregnancy?
Gigartina Stellata Extract is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
What skin types is Gigartina Stellata Extract for?
Gigartina Stellata Extract suits: normal, dry, combination, sensitive.
What is Gigartina Stellata Extract and what does it do in cosmetics?
Red algae extract from Gigartina stellata.
What's the INCI name for Gigartina Stellata Extract?
The INCI name is Gigartina Stellata Extract. It may also appear as: Mastocarpus Stellatus Extract.
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