Bladderwrack is used for thyroid disorders including underactive thyroid (myxedema), over-sized thyroid gland (goiter), and iodine deficiency. It is also used for obesity, arthritis, joint pain, “hardening of the arteries” (arteriosclerosis), digestive disorders, heartburn, “blood cleansing,” constipation, bronchitis, emphysema, urinary tract disorders, and anxiety. Other uses include boosting the immune system and increasing energy.