HerbilousOpen the interactive guideHERB PROFILE · EDUCATIONAL REFERENCE
Bladderwrack
Important safety information: Contraindicated in hyperthyroidism, pregnancy and breastfeeding. Review with thyroid disease, cardiac symptoms, thyroid medicines including levothyroxine, and all iodine-containing products. Marine algae may accumulate heavy metals, so use only tested, authenticated material.
Herbal actions
- Thyroid stimulant where iodine deficiency is present
- Demulcent
- Mineral-rich seaweed
Traditional and practitioner uses
These uses are presented for historical and educational context. They are not treatment claims.
- Historical use in iodine-deficient hypothyroid states
- Historical weight-management preparations where thyroid deficiency was suspected
- Traditional rheumatic-complaint use
Main constituents
Iodine and other trace minerals, alginic acid, fucans or fucoidan, polyphenols, lipids and sterols
Preparation overview
Tea: Not recommended for self-dosing. Iodine content varies greatly. Household seaweed preparations cannot be reliably converted to the 1:1 liquid-extract reference dose.
Liquid extract reference: 1:1 liquid extract: 4.5–8.5 mL/day (30–60 mL/week)
Preparation strengths are not interchangeable. Open the interactive guide for the complete evidence notes and sources available for this herb.
Herbilous provides educational information only. It does not diagnose, prescribe, or replace professional medical advice. Seek urgent care for severe or worsening symptoms.