What Is the Difference Between Thyrolar & Armour Thyroid?

Thyroid disease may require hormone replacement therapy. If you are prescribed a combination T3/T4 treatment for thyroid hormone replacement, you could be prescribed Armour Thyroid or Thyrolar. There are important differences.

Armour Thyroid

• Armour Thyroid is a natural dessicated product containing levothyroxine (T4) and L-triiodothyronine (T3) from pig thyroid glands which are dried and powdered to manufacture into pill form by Forest Laboratories, Inc.

  The active ingredient in Armour Thyroid is Thyroid Powder, USP.

  Inactive ingredients include:

  Dextrose
  Microcrystalline Cellulose
  Sodium Starch Glycolate
  Calcium Stearate
  Opadry White (whitening agent)

Thyrolar

• Thyrolar is a synthetic product containing levothyroxine sodium (T4) and L-triiodothyronine (T3). Thyrolar is manufactured by Forest Laboratories, Inc.

  The active ingredient in Thyrolar is a synthetic combination of T3 and T4.

  Inactive ingredients include:

  Calcium Phosphate
  Colloidal Silicon Dioxide
  Corn Starch
  Magnesium Stearate
  Lactose
  Dyes

Armour vs Thyrolar T3/T4 Combinations

• Armour Thyroid includes 38 mcg of levothyroxine (T4) and 9 mcg liothyronine (T3) per grain. Thyrolar contains 50 mcg T4 and 12.5 mcg T3 per grain.

Allergy Considerations

• Allergic responses to fillers may be present in both while the dyes in Thyrolar present an additional allergic consideration.

Other Considerations

• Synthetic medication may be difficult to tolerate in some people.

  Thyrolar may be preferred by vegetarians over Armour.

  Doctors differ in prescribing based on experience and education. Doctors may have a definite preference or may refuse to prescribe one over the other.