There are many different types of algae:
Bladderwrack - Fucus vesiculosus L.; saw kelp - Fucus serratus L.; knotted kelp - Ascophyllum nodosum Le Jol.; strap kelp - Fucus elongatus L
The salt of alginic acid obtained from various brown algae, the alginates, are used in the food industry as thickeners, gelling agents, emulsion stabilizers and in medicine as protective colloids.
The dried algae body (thallus) is used phytotherapeutically. It is important to note that seaweed may contain iodine in varying concentrations, as well as arsenic, lead, cadmium and mercury.
HMPC monograph: Traditional-use: during a calorie-reduced diet for weight reduction
ESCOP: not processed
Commission E: negative decision, with insufficient evidence of efficacy, from a dosage > 150 µg iodine/day triggering or worsening of hyperthyroidism
Brown algae are also used for hyperthyroidism, obesity, arteriosclerosis, constipation and rheumatism. Also used as an additive in toothpastes, hair lotions, moisturizing face creams and peeling masks. Also an additive to fruit juice drinks, but also as animal feed, fertilizer, sprays and for the extraction of iodine; see also negative adoption of Commission E.