Bladderwrack (Fucus vesiculosus)

Tier 3 — weak evidence · Thyroid · Iodine · Metabolic · Sea vegetable

A brown seaweed rich in iodine, fucoidan polysaccharides, alginate fibre, and polyphenols. Used traditionally as thyroid and metabolic support due to iodine content. Fucoidan has independent anti-inflammatory and potential anti-tumour properties. Iodine content varies extremely widely between products (500–8,000 mcg/g), creating real thyroid disruption risk. Should not be used alongside thyroid medication or by those with autoimmune thyroid conditions.

Dose: 100–300 mg standardised extract/day