Bladderwrack: Benefits, How To Use, And Precautions

Written by Aparna Mallampalli

Bladderwrack is widely used in traditional medicine as a supplement and is known for its medicinal properties. It is a nutrient-dense seaweed believed to have impressive health benefits and help manage numerous health conditions. What does science say about it? Does it have any side effects? Continue reading to find out.

What Is Bladderwrack?

Bladderwrack is a seaweed that grows on the coasts of the North Sea, Western Baltic Sea, and the Atlantic and Pacific Oceans. It is commonly known as black tang or brown seaweed. Many consume bladderwrack for its medicinal properties. It is especially used for managing thyroid disorders as it contains iodine, an essential component for maintaining normal thyroid function.

Continue reading to know about the nutritional value of bladderwrack.

Bladderwrack Nutrition Profile

Hundred grams of dried bladderwrack powder contain:

Protein12.99 g
Lipid3.75 g
Ash20.71 g
Calcium984.73-1160.27 mg
Iron13.34 mg-18.99 mg
Potassium3781.35mg-9316.28 mg
Manganese8.28 mg – 1.96 mg
Sodium1836.82 mg – 4575.71 mg
Amino Acids11.90 g
Magnesium1.96 mg – 8.28 mg

Bladderwrack is chock-full of nutrients and has multiple health benefits. Let’s understand how it can keep you healthy.

Bladderwrack Health Benefits

1. Improves Gastrointestinal Function

Bladderwrack contains high levels of dietary fiber, which promotes gastrointestinal health. Dietary fiber helps regulate the intestinal flow and also stimulates the growth of gut-friendly microbiota.

2. Helps Manage Diabetes

Bladderwrack contains fucoidans, bioactive compounds with potent anti-diabetic properties. They can reduce glucose absorption into the bloodstream, increase serum insulin levels, and help manage diabetes. Animal studies found that oral intake of bladderwrack reduced fasting blood glucose levels.

3. Has Anticoagulant Properties

The fucoidans in bladderwrack make it an excellent anticoagulant. Animal studies found that fucoidans could mimic the action of heparin, a potent anticoagulant. This may reduce the risk of ischemic stroke by minimizing blood clotting tendency in people with a history of hypertension and diabetes. However, the exact mechanism of how it works is not yet clear and needs further research.

4. Has Antitumor Properties

Fucoidans have antitumor properties and are effective against breast cancer, colon cancer, and lung carcinoma cells.

5. Antiviral Properties

The fucoidans in bladderwrack can effectively inhibit poliovirus III, adenovirus III, ECHO6 virus, herpes simplex virus (HSV), cytomegalovirus (CMV), dengue virus. However, the exact mechanism remains unclear.

If you are wondering how to include bladderwrack in your diet, read the next section.

How To Take Bladderwrack And Recommended Dosage

Seaweeds, in general, have a fishy smell, which can be unpleasant for a few when consumed as they are or in powdered form. That is why bladderwrack and other seaweed supplements are available in capsules.

It is best to consult a doctor to determine the ideal dosage (usually, it does not exceed three capsules), depending on your health condition and nutritional requirements, as unregulated intake may cause side effects.

Side Effects Of Bladderwrack

Bladderwrack is possibly safe when taken in small amounts. But anecdotal evidence suggests that excess intake may cause a few side effects like:

  • Nausea And Vomiting: Its unpleasant taste and odor may make you nauseous and cause vomiting.
  • Diarrhea: A few people reported experiencing diarrhea and sticky stools after taking bladderwrack supplements. This might be due to bladderwrack’s nutrient-dense nature. You may also experience dehydration due to diarrhea. Hence, consume adequate amounts of fluids to combat this.
  • Bloating: Excess consumption of bladderwrack may cause bloating and gastric pain, which may be due to the high fiber content. Stay hydrated to minimize this side effect.
  • Tingling Sensation In The Throat: If you are allergic to bladderwrack, it may cause itching and tingling sensation in the throat.
  • May Aggravate Acne: Excess consumption of bladderwrack may worsen acne due to its high iodine content. However, there is no research to prove the exact mechanism.

If you experience any of the symptoms, stop consuming bladderwrack supplements. If the effects persist for over three days, consult a doctor immediately.

To Conclude

Bladderwrack supplements are rich in nutrients and a great way to improve your overall health. They are especially beneficial if you have iodine deficiency, thyroid dysfunction, and diabetes. However, do not consume the supplements without consulting your doctor, as excess intake may cause adverse effects.

Expert’s Answers For Readers’ Questions

Can I take bladderwrack every day?

Yes, you can take bladderwrack every day only if advised by the doctor.

Who should not take bladderwrack?

Bladderwrack is safe when taken as per the doctor’s advice. However, avoid it if you are allergic to seaweeds and have asthma. Also, avoid consuming it if you are pregnant or breastfeeding.

Can bladderwrack cause high blood pressure?

Excessive iodine intake may cause high blood pressure. Since bladderwrack contains iodine, excess intake may increase blood pressure levels.

Is bladderwrack good for skin?

Bladderwrack is rich in nutrients and antioxidants that helps maintain overall health and your skin health. Moreover, antioxidants can reduce oxidative damage, one of the main causes of premature aging.


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Aparna is a professor-turned-content writer with over 5 years of experience in life sciences. Her passion for writing and interest in the healthcare and wellness industry pushed her toward a career in content writing. She has a master’s in Microbiology and aims to use her knowledge of life sciences to break down complex information into easily understandable content for the readers. When she’s not working, Aparna loves cooking and collecting keychains.