Botanical Overview
Fucus vesiculosus, commonly known as Bladderwrack, Black Tang, Rockweed, or Sea Oak, belongs to the family Fucaceae. This marine brown alga grows in the cold waters of the Northern Atlantic coasts of Europe and North America. The medicinal part used is the thallus (the algal body), harvested from clean coastal areas.
Energetics
Fucus vesiculosus exhibits a cooling temperature with moistening qualities. Its taste is primarily salty and bitter, reflecting its marine origin. Its energetics include a descending directionality and tonifying action, influencing the body’s qi and fluids.
Primary Actions
- Provides a natural source of iodine
- Supports thyroid gland function
- Exerts mild anti-inflammatory effects
Indications
Western
- Hypothyroidism symptoms such as fatigue and weight gain
- Goiter and iodine deficiency disorders
- Obesity associated with metabolic sluggishness
- Constipation
Syndromes
- Thyroid dysfunction
- Iodine deficiency
- Metabolic sluggishness
TCM
Not traditionally used or documented in TCM.
Ayurveda
Not established in classical Ayurvedic medicine.
Unani
Limited use; not widely documented.
Constituents & Mechanisms
Rich in iodine and polysaccharides such as alginate, fucoidan, and laminarin, along with phenolic compounds and mannitol. These constituents contribute to its thyroid tonic effect and anti-inflammatory properties.
Dosage & Preparations
- Powder: 1-3 grams daily
- Tincture (1:5, 40% alcohol): 2-5 mL 1-3 times daily
- Infusion: 2-4 grams 1-2 times daily
Safety & Contraindications
Due to high iodine content, caution is advised in individuals with hyperthyroidism or thyroid disorders. Use is contraindicated during pregnancy and lactation due to lack of established safety data. Possible mild gastrointestinal discomfort may occur. Monitor thyroid function if used long term. Avoid in case of iodine allergy. Potential interactions include additive effects with thyroid hormone medications and anticoagulants.
Astrological Correspondences
No well-supported planetary or elemental rulers identified in authoritative herbal esoteric sources.
Selected References
- Fucus vesiculosus – Bladderwrack, PFAF Database
- Community herbal monograph on Fucus vesiculosus L., thallus, EMA/HMPC (2010)
- Iodine, NIH Linus Pauling Institute (2023)
- Bladderwrack Uses, Side Effects & Warnings, WebMD