Seaweeds, Kelps, and Wracks


💊 Chemical information

Seaweeds, Kelps, and Wracks


In Eur..

Ph. Eur. 6.2

(Kelp; Fucus vel Ascophyllum). The fragmented dried thallus of Fucus vesiculosus or F. serratus or Ascophyllum nodosum. It contains not less than 0.03% and not more than 0.2% of total iodine, calculated with reference to the dried drug. It has a salty and mucilaginous taste, and an unpleasant marine odour. Protect from light. The Ph. Eur. title was formerly Bladderwrack and the BP 2008 gives Bladderwrack and Fucus as approved synonyms.

💊 Profile

Dried seaweeds of various species are ingredients of a number of herbal preparations. The terms kelps and wracks have been used indiscriminately for each other and other brown seaweeds. For example, Kelp (Ph. Eur. 6.2) refers to a preparation of various species of wrack and was formerly titled Bladderwrack. Bladder wrack (Fucus vesiculosus), toothed wrack (F. serratus), or knotted wrack (Ascophyllum nodosum) are included in preparations given for various disorders including obesity, constipation, and iodine deficiency. Kelps refer properly to species of Laminaria and Macrocystis. They are present as an ingredient of several dietary supplements and herbal preparations, including for use in obesity; they have also been used as a source of iodine. Laminaria stalks are used for dilation of cavities or the cervix. Fucoidan is a sulfated polysaccharide extracted from brown seaweeds.


F. vesiculosus has been used in homoeopathic medicines under the following names: Fucus v.

Adverse effects and precautions.

Kelp can concentrate various heavy metals; auto-immune thrombocytopenic purpura and disordered erythropoiesis in a patient who had been taking kelp tablets for 6 weeks was attributed to the arsenic content of the preparation.1 Clinical hyperthyroidism has also been reported in patients taking kelp-containing preparations as part of a slimming regimen2or a dietary supplement.3 The FDA has advised that preparations containing compounds such as kelp, which may be taken orally in bulk laxatives or weight-control preparations, should be taken with a full glass of water or, if the patient has difficulty in swallowing, they should be avoided. Such compounds swell into masses that may obstruct the oesophagus if not taken with sufficient water.
1. Pye KG, et al. Severe dyserythropoiesis and autoimmune thrombocytopenia associated with ingestion of kelp supplements. Lancet 1992; 339: 1540
2. de Smet PA, et al. Hyperthyreoidie tijdens het gebruik van kelp tabletten. Ned Tijdschr Geneeskd 1990; 134: 1058–9
3. Eliason BC. Transient hyperthyroidism in a patient taking dietary supplements containing kelp. J Am Board Fam Pract 1998; 11: 478–80.

💊 Preparations

Proprietary Preparations

Arg.: Sual; Braz.: Redufat; Fr.: Dictyolone; Dyctiol†; UK: Adios Max; Phytoslim. Multi-ingredient: Arg.: Arceligasol; Celu-Atlas; Centellase de Centella Queen; Centellase Gel; Herbaccion Celfin; Herbaccion Diet; KLB6 Fruit Diet; Nio Marine; Redualgas; Silueta Plus; Varisedan Gel; Yerba Diet; Austral.: Bioglan Zellulean with Escin; Gartech; Plantiodine Plus†; PMT Complex†; Braz.: Composto Anticelulitico†; Composto Emagrecedor†; Emagrevit†; Emagrex†; Obesidex†; Obesifran†; Canad.: Damiana-Sarsaparilla Formula†; Kelp B Cider Vinegar; Chile: Celltech Gold; Fucus Compuesto†; Cz.: Cajova Smes pri Redukcni Diete†; Reduktan; Fr.: Algoceanic†; Dellova†; Dragees Fuca; Duo Reparation; Marinol; Maxidraine†; Obeflorine; Promincil†; Tonimer; Ger.: Krophan N†; Viscophyll†; Indon.: Naturica DFM; Ital.: Fave di Fuca; Neoform†; Skarflex; Mex.: Lecifar-K†; Pol.: Herbaton; S.Afr.: Activex 40 Plus; Spain: Fucusor†; Lipograsil; UK: Adios; Boldex; Gerard House Water Relief Tablets; HealthAid Boldo-Plus; Kelp Plus 3; Water Naturtabs; Weight Loss Aid; USA: KLB6; Venez.: Demerung; Fugras; Lecivar Plus.
Published May 08, 2019.