Here are the basics of hypothyroid meds...
The active ingredients, T4 and/or T3, in any hypothyroid med are the same, no matter the brand. They are identical versions of the hormones that your own gland would make if it could. Different people respond differently to each brand due primarily to their reactions to the kind of fillers, binders, and dyes that bulk up the T4/T3 into a compressed tablet. One person's success with any one brand doesn't guarantee your
success with it, so it isn't especially useful to compare reactions among users.
The natural dessicated thyroid that so many of us have success with is made under fewer brand names than the synthetics. Armour, Naturethroid, and Westhroid all contain both T4 and T3, which makes them superior products for people who have trouble converting T4 or whose cells are resistant to T3. Again, the active ingredients are the same. Anyone who is hypo needs the same active ingredients. The major differences in any of the brands are the inert ingredients, which can make a huge difference in the way someone absorbs the active ingredients.
I've only tried two... Synthroid which definitely was not for me, and Armour which seems to be just what the doctor ordered.