The widespread use of seaweed as a cosmetic originated in France with "thalassotherapy" in which seaweed used to be used as an ingredient in seawater treatments. The term “thalassotherapy “ comes from the Greek "thalassa" meaning sea and refers to therapeutic use of seawater. 
Modern thalassotherapy orginated with the "inventeur de la Mer", Richard Russell, a Frenchman who wrote that  "it is imperative to drink seawater, bathe in the sea and eat everything that, by coming from the sea, contains the virtue of the sea" (1750) to preserve one’s wellbeing.

Over the twentieth century thalassotherapy centres sprang up all over Europe using seawater, seaweed and sludge from the sea.
Seaweed-based treatments are particularly useful in slimming therapies, as seaweed contains active principles that favour the elimination of toxins.
Ascophyllum nodosum is a natural concentrate of minerals, vitamins and iodine. It helps the metabolic system and gives a sheen to the skin thanks to the moisturising properties of these elements.  
Ascophyllum nodosum can also have anti-bacterial properties, stimulates the immunity system and the physiological functions of the organism and improves blood circulation through the elimination of the toxins.