Dr.Broda Barnes is usually referred to as the thyroid authority. Dr.David Brownstein practice is mainly thyroid issues. They both recommend natural hormones. The online link has multitudes of patients that switched & were much happier. There is no money in natural hormones & pharma companies would like to destroy the competition.
Barnes used a desiccated thyroid extract from Armour Thyroid almost exclusively, stating anecdotally that patients experienced much better improvement of symptoms with the natural extract rather than synthetic drugs. He claimed that the even with synthetic combination drugs containing T4 and T3, patients were left with symptoms (dry skin & fluid retention), that upon switching to desiccated thyroid extract would resolve.