Differences Between Natural Desiccated Thyroid and Levothyroxine
DESCRIPTION
NATURAL DESICCATED THYROID
NDT is a "natural" medication, derived from the dried thyroid glands of pigs, and contains natural forms of both the T4 (thyroxine) and T3 (triiodothyronine) thyroid hormones. NDT also includes cofactors, including the T1 and T2 thyroid hormone metabolites, and calcitonin.
LEVOTHYROXINE
Levothyroxine is a "synthetic" medication, and a synthetized form of the T4 (thyroxine) thyroid hormone
HISTORY
NATURAL DESICCATED THYROID
NDT has been used since the late 1800s
LEVOTHYROXINE
Levothyroxine has been used since the 1950s
BRAND NAMES
NATURAL DESICCATED THYROID
Brand name NDT drugs available in the U.S. market include Armour Thyroid, Nature-Throid, and WP Thyroid
LEVOTHYROXINE
Brand name levothyroxine drugs available in tablet form in the U.S. market include Synthroid, Levoxyl, and Unithroid. Levothyroxine is also available as Tirosint capsules, and Tirosint-SOL oral solution.
GENERIC VERSIONS
NATURAL DESICCATED THYROID
NP Thyroid is considered generic for Armour Thyroid.
LEVOTHYROXINE
There are numerous generic levothyroxine tablet forms of levothyroxine manufactured for the U.S. market. There are no generics for Tirosint capsules or Tirosint-SOL oral solution.
FDA STATUS
NATURAL DESICCATED THYROID
NDT is an FDA-regulated medication
LEVOTHYROXINE
Levothyroxine is an FDA-approved medication
FDA STANDARDS
NATURAL DESICCATED THYROID
The active ingredients in NDT are standardized by the FDA, and the T4 and T3 content must fall within + or - 10% of the potency guidelines
LEVOTHYROXINE
The active ingredient, levothyroxine, is standardized by the FDA, and must fall within + or - 5% of the stated potency
SAFETY
NATURAL DESICCATED THYROID
Studies show that appropriate dosages of NDT can safely treat hypothyroidism
LEVOTHYROXINE
Studies show that appropriate dosages of levothyroxine can safely treat hypothyroidism