Angel's hair seaweed, also known as Centroceras clavulatum or sometimes Gracilaria species, has a history of traditional use in East Asian cultures for a variety of health and beauty applications, including as a topical or dietary aid for hair health. In traditional Chinese and Japanese herbal medicine, various seaweeds have been used as part of remedies aimed at supporting hair growth or preventing hair loss, primarily due to their high mineral content, particularly iodine, iron, and other micronutrients believed to nourish the scalp and follicles.

However, the specific scientific evidence supporting Angel's hair seaweed for hair loss or thinning is extremely limited. Most claims are extrapolated from the general nutritional benefits of edible seaweeds, which are indeed rich in vitamins and trace elements essential for overall health and potentially beneficial for hair if a deficiency exists. There have been no well-controlled clinical trials specifically investigating Angel's hair seaweed for treating hair loss or thinning in humans.

Thus, while its use is justified by tradition and the general nutritional profile of seaweeds, the direct evidence for efficacy in hair loss is anecdotal at best. The evidence rating is 1, reflecting weak support grounded in tradition rather than scientific validation.