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