Fucus vesiculosus is a brown seaweed that grows on the northern coasts of the Atlantic and Pacific oceans, and the North and Baltic seas. Its name is sometimes used for Ascophyllum nodosum, which is another brown seaweed that grows alongside Fucus vesiculosus. These species are often included in kelp preparations along with other types of seaweed.

The Vietnamese consume seaweed as food in various forms: raw as salad and vegetable, pickle with sauce or with vinegar, relish or sweetened jellies and also cooked for vegetable soup. As herbal medicine, seaweed is has been used for traditional cosmetics, treatments for cough, asthma, hemorrhoid, boils, goiters, stomach ailments, urinary diseases, reducing the incidence of tumors, ulcers and headaches. Although Vietnam has an abundance of algae floral with total number of species is estimated to be nearly 1,000 species of which there are 638 species of marine algae identified.

Black-tang, bladder, bladder fucus, bladderwrack, Blasen-tang, brown algae, common seawrack, cut weed, Dyers fucus, edible seaweed, fucoidan, fucoxantin, Fucus, green algae, Hai-ts'ao, kelp, kelpware, knotted wrack, Meereiche, Quercus marina, popping wrack, red algae, red fucus, rockrack, rockweed, schweintang, sea kelp, sea oak, seetang, seaware, seaweed, sea wrack, swine tang, tang, Varech vesiculeux, vraic, wrack.

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Antibacterial/antifungal (Grade: C)
Laboratory study suggests antifungal and antibacterial activity of bladderwrack. However, there are no reliable human studies to support use as an antibacterial or antifungal agent.

Anticoagulant (blood-thinner) (Grade: C)
Laboratory study has found anticoagulant properties in fucans or fucoidans, which are components of brown algae such as bladderwrack. However, there are no high quality human studies available to support this use.

Antioxidant (Grade: C)
Laboratory study suggests antioxidant activity in fucoidans, which are components in some brown algae. However, there are no high quality human studies available to support use as an antioxidant.

Cancer (Grade: C)
Several brown algae, including bladderwrack (

Diabetes (Grade: C)
Based on animal research, extracts of bladderwrack may lower blood sugar levels. However, there are no reliable human studies available to support a recommendation for use in diabetes.

Goiter (thyroid disease) (Grade: C)
Bladderwrack contains variable levels of iodine. As a result, it has been used to treat thyroid disorders such as goiter. While the evidence does suggest thyroid activity, there is not enough research to support this use of bladderwrack.

Weight loss (Grade: C)
Bladderwrack and other seaweed products are often marketed for weight-loss. However, safety and effectiveness have not been studied in humans.