Bladderwrack, Brown Marine Algae, Brown seaweed, Egg Wrack, Hebridean Seaweed, ID-alG, Irish Brown Seaweed, Kelp, Knotted Wrack, Norwegian Kelp, Rockweed, Tasco.


Overview Information

Ascophyllum nodosum is a type of brown seaweed. It is found along the shorelines in cold areas of the world, such as Northern Canada, United States, and Europe. Ascophyllum nodosum is now protected in many countries because of over-harvesting for a chemical called alginate.

Ascophyllum nodosum is taken by mouth for dental health, weight loss, or as a source of the mineral iodine. Don't confuse Ascophyllum nodosum with other kinds of seaweed like Bladderwort, Blue-green Algae, Brown Algae, Fucus vesiculosus, or Laminaria, or with the chemical Algin that comes from seaweed.

How does it work?

Ascophyllum nodosum contains nutrients such as large sugars (carbohydrates), fats, and the mineral iodine. Ascophyllum nodosum might help the body kill cancer cells and reduce swelling.

Uses & Effectiveness?

Insufficient Evidence for

  • Tooth plaque. Early research shows that taking Ascophyllum nodosum (ProDen PlaqueOff) might help to reduce the build-up of plaque on the teeth.
  • A mild form of gum disease (gingivitis). Early research shows that taking Ascophyllum nodosum (ProDen PlaqueOff) does not prevent gingivitis.
  • Iodine deficiency. Ascophyllum nodosum contains iodine. Early research shows that taking Ascophyllum nodosum can increase iodine levels in women who have low levels of iodine in the body.
  • Stomach or intestinal problems.
  • Weight loss.
  • Other conditions.
More evidence is needed to rate the effectiveness of Ascophyllum nodosum for these uses.

Side Effects

Side Effects & Safety

When taken by mouth: Ascophyllum nodosum is POSSIBLY SAFE for adults when taken daily for up to 6 months. Side effects are rare but might include stomach problems. Ascophyllum nodosum can accumulate high levels of heavy metals. Purchasing a product that is certified as being free of heavy metals can reduce the risk of heavy metal exposure.

Special Precautions & Warnings:

Pregnancy and breast-feeding: There is not enough information available about the safety of taking Ascophyllum nodosum when pregnant or breast feeding. Stay on the safe side and avoid use.



We currently have no information for ASCOPHYLLUM NODOSUM Interactions.



The appropriate dose of Ascophyllum nodosum depends on several factors such as the user's age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for Ascophyllum nodosum. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.

View References


  • Hall, A. C., Fairclough, A. C., Mahadevan, K., and Paxman, J. R. Ascophyllum nodosum enriched bread reduces subsequent energy intake with no effect on post-prandial glucose and cholesterol in healthy, overweight males. A pilot study. Appetite 2012;58(1):379-386. View abstract.
  • Le Tutour B, Benslimane F, Gouleau MP, and et al. Antioxidant and pro-oxidant activities of the brown algae, Laminaria digitata, Himanthalia elongata, Fucus vesiculosus, Fucus serratus and Ascophyllum nodosum. J Applied Phycology 1998;10(2):121-129.
  • Paradis, M. E., Couture, P., and Lamarche, B. A randomised crossover placebo-controlled trial investigating the effect of brown seaweed (Ascophyllum nodosum and Fucus vesiculosus) on postchallenge plasma glucose and insulin levels in men and women. Appl.Physiol Nutr.Metab 2011;36(6):913-919. View abstract.
  • Bahar B, O'Doherty JV, Hayes M, Sweeney T. Extracts of brown seaweeds can attenuate the bacterial lipopolysaccharide-induced pro-inflammatory response in the porcine colon ex vivo. J Anim Sci 2012;90 Suppl 4:46-8. View abstract.
  • Combet E, Ma ZF, Cousins F, et al. Low-level seaweed supplementation improves iodine status in iodine-insufficient women. Br J Nutr 2014;112:753-61. View abstract.
  • Corona G, Ji Y, Anegboonlap P, et al. Gastrointestinal modifications and bioavailability of brown seaweed phlorotannins and effects on inflammatory markers. Br J Nutr 2016;115(7):1240-53. View abstract.
  • Gabbia D, Dall'Acqua S, Di Gangi IM, et al. The phytocomplex from Fucus vesiculosus and Ascophyllum nodosum controls postprandial plasma glucose levels: An in vitro and in vivo study in a mouse model of NASH. Mar Drugs 2017;15(2). pii: E41. View abstract.
  • Jiang Z, Abu R, Isaka S, et al. Inhibitory effect of orally-administered sulfated polysaccharide ascophyllan isolated from ascophyllum nodosum on the growth of sarcoma-180 solid tumor in mice. Anticancer Res 2014;34(4):1663-71. View abstract.
  • Marinval N, Saboural P, Haddad O, et al. Identification of a pro-angiogenic potential and cellular uptake mechanism of a LMW highly sulfated fraction of fucoidan from Ascophyllum nodosum. Mar Drugs 2016;14(10). pii: E185. View abstract.
  • Mayer MA, Finlayson G, Fischman D, et al. Evaluation of the satiating properties of a nutraceutical product containing Garcinia cambogia and Ascophyllum nodosum extracts in healthy volunteers. Food Funct 2014;5:773-9. View abstract.
  • O'Neill A, Gupta BS, Phillips DH. Distribution of arsenic and risk assessment of activities on a golf course fertilised with arsenic-containing Ascophyllum nodosum seaweed. Sci Total Environ 2014;482-483:252-9. View abstract.
  • Seeley RH, Schlesinger WH. Sustainable seaweed cutting? The rockweed (Ascophyllum nodosum) industry of Maine and the Maritime Provinces. Ann N Y Acad Sci 2012;1249:84-103. View abstract.
  • Simmons-Boyce JL, Purcell SL, Nelson CM, MacKinnon SL. Dietary Ascophyllum nodosum increases urinary excretion of tricarboxylic acid cycle intermediates in male Sprague-dawley rats. J Nutr 2009;139:1487-94. View abstract.
  • Sorge US, Henriksen M, Bastan A, et al. Short communication: Iodine concentrations in serum, milk, and tears after feeding Ascophyllum nodosum to dairy cows-A pilot study. J Dairy Sci 2016;99:8472-6. View abstract.
  • Steevensz AJ, Mackinnon SL, Hankinson R, et al. Profiling phlorotannins in brown macroalgae by liquid chromatography-high resolution mass spectrometry. Phytochem Anal 2012;23(5):547-53. View abstract.
  • Terpend K, Bisson JF, Le Gall C, Linares E. Effects of ID-alG on weight management and body fat mass in high-fat-fed rats. Phytother Res 2012;26(5):727-33. View abstract.
  • van Dijken JW, Koistinen S, Ramberg P. A randomized controlled clinical study of the effect of daily intake of Ascophyllum nodosum alga on calculus, plaque, and gingivitis. Clin Oral Investig 2015;19:1507-18. View abstract.
  • van Ginneken VJ, Helsper JP, de Visser W, et al. Polyunsaturated fatty acids in various macroalgal species from North Atlantic and tropical seas. Lipids Health Dis 2011;10:104. View abstract.
  • Zhang W, Du JY, Jiang Z, et al. Ascophyllan purified from Ascophyllum nodosum induces Th1 and Tc1 immune responses by promoting dendritic cell maturation. Mar Drugs 2014;12(7):4148-64. View abstract.

Vitamins Survey

Have you ever purchased ASCOPHYLLUM NODOSUM?

Did you or will you purchase this product in-store or online?

Where did you or where do you plan to purchase this product?

Where did you or where do you plan to purchase this product?

What factors influenced or will influence your purchase? (check all that apply)

Vitamins Survey

Where did you or where do you plan to purchase this product?

Do you buy vitamins online or instore?

What factors are most important to you? (check all that apply)

This survey is being conducted by the WebMD marketing sciences department.Read More


CONDITIONS OF USE AND IMPORTANT INFORMATION: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you.

This copyrighted material is provided by Natural Medicines Comprehensive Database Consumer Version. Information from this source is evidence-based and objective, and without commercial influence. For professional medical information on natural medicines, see Natural Medicines Comprehensive Database Professional Version.
© Therapeutic Research Faculty 2018.