Sea moss (Irish moss)

Tier 3 — weak evidence · Thyroid · Minerals · Gut

Heavily promoted on social media but lacks any clinical trial evidence. Iodine content varies enormously — some products deliver over 10 times the safe upper limit per serving, causing thyroid dysfunction or hyperthyroidism. People with thyroid disease are at particular risk. The trendy gel form is just seaweed with no proven benefit over any other food source.

Dose: No evidence-based dose; iodine content is dangerously unpredictable; test thyroid function before any use