(Other nutrients, although not directly involved in thyroid function, are also essential for optimal immune system, gut, liver, and adrenal function.) Most people who are diagnosed with Hashimotos will also present with low levels of selenium , vitamin E , and glutathione, as well as zinc and ferritin (the iron storage protein)
Vitamin B12 is non-toxic for dogs, and supplements come in different forms, such as cyanocobalamin and methylcobalamin
Some studies have suggested BPC-157 interacts with nitric oxide signaling pathways that regulate vascular function
For a 75 to 90kg adult, that translates roughly to 190 to 900mcg daily, which brackets the 200 to 500mcg range being used in practice