Otherwise, I can't see where it would be of any help at all. The answer is no. Hypothyroidism today is rarely caused by iodine deficiency. All the iodine in the world won't likely correct a poorly functioning thyroid gland, the causes of which have nothing to do with iodine. And bladderwrack isn't without risk.
Prolonged ingestion can cause problems with iron absorption, leading to anemia.
It is also very high in salt content which isn't safe for some people. Lastly, some bladderwrack preparations can contain high levels of toxic substances such as arsenic. And remember, herbal preparations aren't highly regulated when it comes to dosage and contaminants. Forget the bladderwrack. It is more likely to lighten your pocketbook than your weight.