Good thoughts above!
Also know that thyroid supplements can be purchased over the counter. They may be something as simple as ground up bovine thyroid. They do contain T3 and T4.
The issue with using them is one of proper dosage. Nearly any level of T3 dose will suppress TSH, inactivating one's thyroid. T3 has a both a short half life and can do something called "pooling" where it accumulates, unused. Leading to an impossible to manage situation.
I believe that "IF" one is going to supplement a functional thyroid with thyroid hormones, do so with name brand, non generic, synthetic T4 at a very small dose. Follow up with labs after a few weeks. It takes 2 weeks for hormones to stabilize with low doses. And don't suppress TSH and shut down the thyroid's natural production.
People somehow don't believe that the thyroid is a "mission critical" gland, and the hormones produced vary over the day, as the body requires them. They mistakenly believe that taking thyroid hormones is a viable replacement for natural production. NOTHING COULD BE FURTHER FROM THE TRUTH. When metabolism is controlled by a pill, the result may be obesity, high blood pressure, high cholesterol, heart disease, fatigue and early death, despite perfect labs.
FACT: We don't know how to properly treat thyroid failure and get normal results. Another fact, the results vary so much from person to person, we can't predict what will happen. We know what may happen.