Fibronol contain Seanol-F, a patent-pending brown seaweed extract. Seaweeds, or algal plants, have long been used by traditional cultures worldwide for food and medicine. Seaweeds are organized into four classes: green algae (Chlorophyceae), blue-green algae (Cyanophyceae), red algae (Rodophyceae), and brown algae (Phaeophyceae). Some green algaes, such as sea spaghetti, are used as food.
Blue-green algae are found in both seawaters, and in fresh waters, such as the well-known edible Klamath Lake blue-green algae, Aphanizomenon flos-aquae. Red seaweeds include agar-agar, dulse, Irish moss and nori. Brown seaweeds include arame, hijiki, kombu and wakame, and are known for their use in Asian cuisines. Both red and brown algae are rich in polysaccharides, which are utilized for their gelling, emulsifying and stabilizing properties. Agar and carrageenan are polysaccharides extracted from red seaweeds; algin is extracted from the brown seaweed giant kelp.