What is fucus vesiculosus? Fucus vesiculosus, also known as bladderwrack, is a brown alga from the Atlantic coast. It contains a wide range of constituents, of which iodine is the most important. What are the benefits of fucus vesiculosus? The iodine in Fucus vesiculosus stimulates the thyroid gland which promotes weight loss by: increasing metabolism suppresses appetite increases energy levels The thyroid gland plays an important role in regulating metabolism as metabolic rate is directly linked to thyroid activity.