Everything you need to know about red seaweed.

Red seaweed, or Rhodophyta, belongs to a taxon of marine algae which groups several different species. It owes its colour to its pigment composition, characterized by the fact that it has only one type of chlorophyll. It is mostly found on the Atlantic coast, usually on the beaches. There are several varieties of red seaweed: Chondrus crispus, Porphyra conchocelis, Palmaria palmata…

In skincare products, as well as the food industry, carrageenan is a sulfated polysaccharide, extracted from red seaweed, that thickens formulations and gives them a gel-like consistency. Traditionally extracted from the species Chondrus crispus (also known as Irish moss), carrageenan now mainly comes from the species Kappaphycus alvarezii and Eucheuma denticulatum.

In skincare and haircare products, red seaweed is often used to thicken formulations. Red seaweed contains carrageenans, natural polysaccharides made from sulfated D-galactose residue. On contact with water, these biopolymers unfold and form a gelled network. Red seaweed is a natural thickening agent, so is often used in organic skincare to replace certain synthetic thickeners like carbomers.

Alongside this essential function, red seaweed has many benefits for the skin. Its humectant properties allow it to hold water in the upper layers of the skin and reduce transepidermal water loss. Red seaweed helps to fight tightness often linked to skin dryness, and reduces the appearance of dehydration wrinkles.

Even better, red seaweed extract is able to boost hyaluronic acid production. As a reminder, hyaluronic acid is a biomolecule, produced by fibroblasts in the dermis, which maintains skin hydration and gives it that plumped, healthy look.

As time goes by, our skin produces less, and of worse quality. With every decade, we lose around 6% of our hyaluronic acid.

This drastic drop leads to atrophy of the fatty pockets located deep in the dermis, causing fine lines and wrinkles on the surface of the skin. So, stimulating production allows us to maintain plumped skin for as long as possible.

Red seaweed also helps to limit imperfections on the skin’s surface. Studies have shown carrageenan’s antibacterial action against Staphylococcus epidermidis and Enterococcus faecalis, two microorganisms responsible for acne and its associated inflammation issues.

Finally, red seaweed extract helps to stimulate ceramide production which tightens the epidermis and limits transepidermal water loss. As a reminder, ceramides are lipids organized as dense and structured lamellae which form the intercellular cement.