Seaweed
海藻 · Hǎi Zǎo
Softens stubborn lumps and supports thyroid balance
What it does
Seaweed is TCM's go-to for soft swellings, what practitioners call 'phlegm nodes.' It softens hard masses like goiters, swollen lymph nodes, and thyroid nodules. The salty taste in TCM has a softening, draining quality. In modern medicine, its iodine content makes it useful for hypothyroidism from iodine deficiency. It's also mildly diuretic, helping reduce water retention.
How to take it
Soak 6–15g dried seaweed in water for 20 minutes, then add to soups or stews. Cook for 15 minutes. Drink the broth and eat the seaweed. Best 2–3 times per week, not daily.
Add a small handful of dried seaweed to a clear vegetable broth
Safety
- High in iodine. Skip if you have hyperthyroidism or take thyroid medication
- Not for people with shellfish allergies, since seaweed is harvested with marine life
- Long-term high doses can cause iodine overload
- Talk to your doctor before starting, especially if you take medication
Where it comes from
Seaweed has been used in TCM for over 2,000 years. The species used (Sargassum) grows along the coasts of southern China and Japan. In classical TCM, seaweed was specifically the answer for thyroid swellings long before iodine was understood. The Tang Dynasty physician Sūn Sī Miǎo prescribed seaweed for goiter as early as the 7th century. Fourteen modern clinical trials have confirmed its effects on thyroid function, hyperlipidemia, and metabolic health.