Hashimotos Thyroiditis is the most common form of hypothyroidism, but it is often misdiagnosed. Dr. Isabella Wentz is the leading expert on this auto-immune disease, and you can almost certainly find the answer to your thyroid questions here: https://thyroidpharmacist.com/
Because supplements (vitamins, minerals, protein powders, etc) are not tested by the FDA and are not regulated, you might never be sure if what they claim on the label is actually in the bottle. ConsumerLab.com is the leading provider of independent test results and information to help consumers and healthcare professionals identify the best quality health and nutrition products. It publishes results of its tests in comprehensive reports at www.consumerlab.com . Since its founding in 1999, CL has tested more than 5,600 products, representing over 850 different brands and nearly every type of popular supplement for adults, children, and pets.