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. 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. The thyroid gland requires iodine to produce thyroid hormones. Increasing iodine levels may result in an increase in thyroid hormone production, leading to increase metabolism. This means the body can burn more calories quicker and less is stored as fat.

It is thought that the increase in metabolism from Fucus vesiculosus can help with weight loss without a change in diet or eating habits. For this reason, Fucus vesiculosus appeal to people who want to loose weight without giving up their favorite foods. However, sustainable weight loss and weight management requires a healthy diet and regular exercise.

There may be negative effects of using Fucus vesiculosus. The thyroid stimulating effects could result in hyperthyroidism, typically characterized by:

• heart palpitations
• increased sweating
• fine tremor
• weight loss with increased appetite
• intolerant of heat
• thinning hair
• insomnia
• irritability
• nervousness
• muscle weakness

Fucus vesiculosus should be avoided in people with diabetes, heart problems and hyperthyroidism. It is not recommended in high doses or for prolonged periods of time because of the high iodine content and the risk of iodine overdose.

Bladderwrack is rarely available as a stand alone supplement. It is typically used as one of the ingredients in weight loss formulas, energy supplements or thyroid support supplements. Bladderwrack usually comes in the form of patches but can be found as liquid extracts.


The information provided has not been evaluated by the Food and Drug Administration and is intended solely for general information and is NOT to replace advice from your physician or other medical professionals and should NOT be relied upon for any diagnosis, treatment or cure. Always check with your doctor before starting any new drug, alternative, natural or herbal treatments and supplements.