If you are curious or are experiencing symptoms commonly associated with low thyroid, you may have an iodine deficiency that is affecting your body's metabolism. Your doctor can check on the symptoms of hypothyroid function or even order an iodine deficiency test. They may even recommend the skin patch test. The test is economical and can be a useful measurement of how fast iodine is absorbing in your body. PT Skin IOSOL is used often for this protocol. External use only.