Synthroid (along with Lexoxyl
and generics), which contains only T4.
Armour (
and other desiccated porcine
thyroid products) contain both T3 and T4. Some people need that extra T3, some don't. It's partly a matter of personal preference and partly what works best for you, preference aside.
You've already had TSH test at 800, so that is a very firm indicator of hypothyroidism. Your symptoms are also classic hypo symptoms.
Be sure to ask your doctor for FREE T3 and FREE T4.