Important warning: please note that all medicines, including herbal medicines, should be taken only on the advice of a qualified practioner. Many beneficial treatements do not work in particular circumstances and may be antagonistic. For all medicines, a particular dose and course of treatment must be observed; it should be noted that more of a good treatment is not necessarily better. You should not treat yourself on the basis of any information given here.

In Europe and North America, many claims have been made for the effectiveness of seaweeds on human health. It has been suggested, amongst other things, that seaweeds have curative powers for tuberculosis, arthritis, colds and influenza, worm infestations, and may even improve one's attractiveness to the opposite sex. Digenea (Ceramiales; Rhodophya) produces an effective vermifugal agent (kainic acid). Recently, aqueous extracts from two red algae of the family Dumontiaceae have been found to inhibit the herpes simplex virus but no tests have been carried out on humans. Carrageenans have been patented as anti-viral agents. Many of the reported medicinal effects of marine algae have not been substantiated. Corallina is being used used in bone-replacement therapy. Stein & Borden (1984) provide an extensive review.

Some kelps may have polysaccharides that may reduce the incidence of breast cancer.
Seaweeds in Chinese medicine