In answer to your question regarding T3 meds, while there are sites
online that say they sell cytomel without a prescription, I would never buy from them, because I have no idea what they are really selling...
There are also some glandular products that are sold over the counter, but they are supposed to have the actual hormone content removed and are simply ground up tissue.
In short, T3 products sold in the U.S require a prescription.