Fucus vesiculosus

Fucus vesiculosus

Plant Family

Fucaceae

Botanical Description

Bladderwrack is a brown seaweed with flat, dichotomously branched fronds 15-100 cm long. It has a central midrib and paired air bladders that help it float. The fronds are olive to dark brown with swollen reproductive tips.

Cautions

Use with caution if you have thyroid disorders due to high iodine content. Not recommended during pregnancy or breastfeeding. May interact with thyroid medications and blood thinners. Only harvest from clean waters.

Habitat

Rocky intertidal zones of cold northern seas.

Harvest Instructions

Harvest by hand at low tide, cutting above the holdfast to allow regrowth. Best harvested in spring and early summer.

Geographic Distribution

North Atlantic Ocean coasts including Iceland, Norway, British Isles, and eastern North America.

Growth Conditions

Attaches to rocks in the intertidal zone. Requires clean, cold seawater.

Plant Size

15-100 cm

Pests & Diseases

May be affected by epiphytic algae. Sensitive to pollution.

Effects on the Body

Rich in iodine to support thyroid function. Anti-inflammatory for joint pain. Supports metabolism and skin health. Contains fucoidan with potential immune benefits.

Active Constituents

Iodine, fucoidan, alginic acid, laminarin, fucoxanthin, vitamins A, B, C, D, E, K, minerals.

Safety Information

Dosage

Capsules: 500-600 mg daily. Tea: 1 teaspoon dried seaweed in hot water. Do not exceed recommended doses due to iodine content.

Culinary Use

Added to soups and stews. Can be dried and powdered as a seasoning. Used in Japanese cuisine.

Folklore & Historical Use

Used for centuries in coastal communities for nutrition and medicine. Traditional remedy for goiter before iodine supplementation was understood.

Scientific Research

Multiple clinical studies support thyroid-supportive effects due to iodine content. A 2014 randomized controlled trial showed reduction in insulin resistance markers. Contains fucoidan with documented anti-inflammatory properties.