Bladderwrack was discovered in 1812. It is a type of seaweed, and as such was the original source of iodine, and used widely to treat goiter, a swelling of the thyroid gland because of an iodine imbalance in the body. Originally it was thought that Bladderwrack could combat obesity by increasing the metabolic rate, as it was a thyroid stimulant and since then, it has been featured in many weight-loss remedies. Sadly, it is not widely used at the moment. The iodine from other sources led to the neglect of seaweed and other kelp products.

Bladderwrack is usually found on the coasts of the North Sea, the Baltic Sea, and the Atlantic and Pacific Oceans. It is a common food in Japan, used in sushi and other foods, and it is also used as an additive and flavoring in Europe.

Bladderwrack is usually used as an ingredient in Kelp tablets or powders which people use as nutritional supplements. It is sometimes just called Kelp, but technically the name Kelp refers to a different seaweed. The nutritional components of this plant include many minerals, algin, beta carotene, iodine, iodine, potassium, mucilage, mannitol, zeaxanthin, and volatile oils.

The main use of Bladderwrack in herbal medicine is as a source of iodine, which is an essential nutrient for the thyroid gland. It has proved most useful in the treatment of Hypothyroidism or Hashimoto's Disease (under active thyroid glands) and goiter. If the thyroid function is regulated, there is an improvement in all the symptoms. This herb may be very helpful in reducing excess weight associated with thyroid problems.

Bladderwrack also has a reputation of relieving the symptoms of rheumatism and rheumatoid arthritis. The uses can be applied internally or as an external application upon inflamed joints. A chemical constituent of Bladderwrack, alginic acid, swells upon contact with water; so, when taken, it forms a type of "seal" at the top of the stomach, and for this reason is also used in several preparations for heartburn. The same ingredient also gives Bladderwrack laxative properties, so it could also be used in the treatment of constipation and other digestive problems. Other uses of Bladderwrack include treating atherosclerosis and strengthening immunity, even though there is no scientific evidence that it works for these purposes.

Dr. Russell in 1750 used a jelly made from Bladderwrack for treating swellings, both internally and externally. He was also successful in dissolving tumors by rubbing in the mucus of Bladderwrack, and afterwards washing the parts with sea-water.