What is the difference between ERFA and Armour Thyroid tablets?

What is the difference between ERFA and Armour Thyroid tablets? Armour® Thyroid Tablets  Allergan™ distributes Armour® Thyroid (thyroid tablets, USP) in the USA in the following strengths:

• 15mg (1/4 grain)
• 30mg (1/2 grain)
• 60mg (1 grain)
• 120mg (2 grain)
• 180mg (3 grain)
• 240mg (4 grain)
• 300mg (5 grain)
• Armour® Thyroid provides 38mcg T4 and 9mcg T3 per grain of thyroid
• The ratio works out to approximately 4.2 T4: 1 T3.

The active ingredient (desiccated natural thyroid) in Armour® Thyroid (thyroid tablets, USP) is derived from porcine (pig) thyroid glands. ERFA™ Thyroid Tablets EFRA™ distributes ERFA™ Thyroid (desiccated thyroid) in Canada in strengths of 30mg, 60mg, and 125mg.

• Note: Desiccated thyroid 60 mg is usually considered equivalent to thyroglobulin 60 mg, levothyroxine sodium (T4) 0.1 mg or liothyronine sodium (T3) 25 μg.
• The ratio is approximately 4.0 T4: 1.0 T3.

EFRA™ Thyroid tablets contain desiccated thyroid containing lactose, derived from porcine thyroid glands. Note that T4 is converted to T3 in your body. Further information on EFRA  can be found at the following link: Learn More