This is from a post by Graveslady that I came across while searching for answers to my own generic to name brand switch... Thought it might be helpful: Original thread is at:
http://www.medhelp.org/posts/show/285258, if you're interested.
All thyroid hormone replacements are synthetic with the exception of Armour which is derived from pig thyroid (beef or sheep).
Generics are just a name change only, from high cost brands name medicines to low cost brand name medicines. Just like all other products sold here in the US: Toilet paper, clothing, clothes soaps, and foods, etc., etc., etc. I buy a lot of generic products, which are made by brand name companies, with the same ingredients. Its the advertising of the "Brand Name" products that is where the high cost comes from. Generics don't carry the "Brand Name" on it nor is it advertised, therefore cost are lower.
Nearly everyone can take synthetic levothyroxine. It is identical to the body's own T4 . However, some patients thinking that "natural" means better, prefer natural thyroid hormones, which are made of desiccated animal thyroid glands.
Brand Names:
Armour Thyroid
Bio-Throid
Cytomel
Levothroid
Levoxyl
Levo-T
Naturethroid
Synthroid
Tapazole
Thyrogen
Thyrolar
Unithroid
Westhroid
Generic Name:
Levothyroxine /L-thyroxine (Synthroid, Levoxyl, Unithroid, etc.)
Liothyronine (Cytomel/T3)
Liotrix (Thyrolar)
Methimazole (Tapazole)
Propylthiouracil / PTU
Natural thyroid (Armour, Naturethroid, Bio-tech)
Thyrotropin alfa (Thyrogen)
Time-released T3, compounded
It is best to stick with the same medication. However, when changing, its best to give it time to work and make sure test are done because levels might change. Once you are regulated on the new med. you should have no more of a problem then when on the old medication.
BTW... Where is Graveslady anyway. Haven't seen her post in a LONG time... :-(