Hai Zao is a type of seaweed or algae with a brownish color and long, slender fronds.
In the 8th century, Chinese physician Wang Tao recommended hai zao as a remedy for an enlarged thyroid. Hai zao is used as a vegetable in Chinese and Japanese cuisine.
Hai Zao can be found in large quantities along the shores of China and Japan and is collected year-round.
References
Share your experience with this herb to help other people