Also Known As: Fucus, Kelp,
Knotted Wrack.
Scientific Name: Fucus vesiculosus; Ascophyllum nodosum; other
Fucus species.
Family: Fucaceae.
People Use This For:
Bladderwrack is used for thyroid disorders, iodine deficiency,
goiter, obesity, arthritis, and rheumatism, "blood
cleansing", to increase energy, constipation, bronchitis,
decreased resistance to disease, and anxiety. Topically,
bladderwrack is used for skin diseases, burns, aging skin, and
insect bites.
Safety: No concerns regarding safety when used orally in
appropriate doses. It is important to obtain traceable
supply free from contamination (1 case of contamination with
heavy metals reported in the 1970’s).1,2
Pregnancy and Lactation: Refer to a Medical Herbalist
Effectiveness: INSUFFICIENT RELIABLE EVIDENCE to RATE
Obesity: Preliminary clinical research suggests that bladderwrack
in combination with lecithin and vitamins doesn't result in
sustained weight loss. More evidence is needed to rate
bladderwrack for this use (combined lecithin, kelp,
multivitamin preparation involving 120 women over 2
years). 3
Mechanism of Action: The applicable part of bladderwrack is the
entire plant. Bladderwrack is a brown seaweed. Bladderwrack
contains high concentrations of iodine, which is present in
varying amounts. Bladderwrack is a source of fiber, minerals such
as iron, and vitamin B12.2
Preliminary clinical research suggests bladderwrack may normalize
the menstrual cycle and have estrogen balancing effects in
premenopausal women. It may also balance progesterone effects4
(case reports on three patients). Preliminary clinical research
suggests topical administration of bladderwrack extract
might reduce skin thickness and other signs of aging.5
Adverse Reactions: Excess Iodine intake is rare in humans outside
of radiation contamination or excessive amounts of seaweed
(or seaweed extracts) intake over a prolonged period. There
is one case report of heavy metal poisoning where
arsenic poisoning occurred with ingestions of a contaminated
kelp product. 6 Another case of arsenic-related poisoning
with bladderwrack ingestion 400 mg three times a day for 3
months resulted in kidney damage.7
Interactions with Herbs & Supplements: Avoid Iodine
supplements at the same time.
Interactions with Drugs:
Antithyroid Drugs: Theoretically, may result in additive
hypothyroid activity, and may lower the level of
availableThyroid hormones.8
Interactions with Foods: None known.
Interactions with Lab Tests:
Radioactive Iodine Uptake: Theoretically, bladderwrack might
interfere with the results of thyroid function tests using
radioactive iodine uptake.2
Thyroid Stimulating Hormone (TSH): Theoretically, bladderwrack
might increase serum TSH levels and test results.8
Thyroxine (T4): Theoretically, bladderwrack might increase serum
T4 levels and test results.8
Interactions with Diseases or Conditions:
Iodine Allergy: Avoid bladderwrack use in people sensitive to
iodine.8
Thyroid Disorders: Prolonged use or excessive amounts of iodides
may exacerbate thyroid gland problems.8
Dosage/Administration: Dr Clare’s Blends: 1 gm per day No typical
dosage.
Specific References: BLADDERWRACK
1. Baker DH. Iodine toxicity and its amelioration. Exp Biol Med
(Maywood) 2004;229:473-8.
2. Phaneuf D, Cote I, Dumas P, et al. Evaluation of the
contamination of marine algae (Seaweed) from the St.
Lawrence River and likely to be consumed by humans. Environ
Res 1999;80:S175-S182.
3. Bjorvell H, Rössner S. Long-term effects of commonly available
weight reducing programmes in Sweden. Int J Obes
1987;11:67-71.
4. Skibola CF. The effect of Fucus vesiculosus, an edible brown
seaweed, upon menstrual cycle length and hormonal status in
three pre-menopausal women: a case report. BMC
Complement Altern Med 2004;4:10.
5. Fujimura T, Tsukahara K, Moriwaki S, et al. Treatment of human
skin with an extract of Fucus vesiculosus changes its
thickness and mechanical properties. J Cosmet Sci
2002;53:1- Pye KG, Kelsey SM, House IM, et al. Severe
dyserythropoeisis and autoimmune
6. thrombocytopenia associated with ingestion of kelp
supplement. Lancet 1992;339:1540.
7. Conz PA, La Greca G, Benedetti P, et al. Fucus vesiculosus: a
nephrotoxic alga? Nephrol Dial Transplant 1998;13:526-7.
8. Food and Nutrition Board, Institute of Medicine. Dietary
Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron,
Chromium, Copper, Iodine, Iron, Manganese, Molybdenum,
Nickel, Silicon, Vanadium, and Zinc. Washington, DC:
National Academy Press, 2002. Available
at: www.nap.edu/books/0309072794/html/.