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Who makes Westhroid and where is it manufactured?

Medically reviewed by Carmen Pope, BPharm. Last updated on Sep 11, 2023.

Official answer


Westhroid is made by RLC Labs located at 1850 E Riverview Dr, Phoenix, Arizona. RLC Labs manufactures, labels, and distributes animal-derived (usually pig) thyroid drug tablets for human use under the brand names of Nature-Throid and WP Thyroid. Nature-Throid and Westhroid are identical preparations and RLC Labs decided to market these under one name: NatureThroid. RLC labs make Westhroid, Nature-Throid, and WP Thyroid.

Westhroid is a natural desiccated thyroid replacement therapy obtained from animal thyroid glands that is a prescription medicine. It contains T4 & T3 replacement hormones and is available in 5 strengths ranging from 2 grains (32.5 mg) to 3 grains (195 mg). It also contains naturally occurring thyroid cofactors T1, T2, calcitonin, and iodine (in trace amounts). Westhroid is not FDA approved.

Westhroid available as

  • ½ grain (32.5mg): 19 mcg T4, 4.5 mcg T3
  • 1 grain (65 mg): 38 mcg T4, 9 mcg T3
  • 1 ½ grain (97.5mg): 57 mcg T4, 13.5 mcg T3
  • 2 grain (130 mg): 76 mcg T4, 18 mcg T3
  • 2 ¼ grain (146.25mg): 85.5 mcg T4, 20.25 mcg T3
  • 2 ½ grain (162.5mg): 95 mcg T4, 22.5 mcg T3
  • 3 grain (195 mg): 114 mcg T4, 27 mcg T3.
  • Get real about hypothyroidism. Get Real Thyroid. 2021.

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