A few examples that should allow you to determine if Armour Thyroid is Obsolete.

How does it work?
How is it different?

References:

http://www.ncbi.nlm.nih.gov/pubmed/23719846
http://www.ncbi.nlm.nih.gov/pubmed/26402162
http://www.nature.com/nrendo/journal/v12/n2/full/nrendo.2015.205.html
http://www.ncbi.nlm.nih.gov/pubmed/21121614
http://www.ncbi.nlm.nih.gov/pubmed/7121261
http://online.liebertpub.com/doi/pdf/10.1089/thy.1998.8.229
http://www.ncbi.nlm.nih.gov/pubmed/23539727