MDElliottMD: home-claude punt-list stub, Top 300 #141

2026-05-23T04:41:14Z

home-claude punt-list stub, Top 300 #141

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Desiccated thyroid (also called natural thyroid, thyroid extract, or by the historical brand Armour Thyroid) is porcine thyroid gland, defatted and powdered, containing both thyroxine (T4) and triiodothyronine (T3) in a fixed ratio of roughly 4:1 by weight as required by the United States Pharmacopeia<ref name="armour-label">FDA Prescribing Information, Armour Thyroid (thyroid tablets, USP), Allergan, current revision. https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=003444</ref>. It was introduced in 1892 by George Murray and has been continuously prescribed since, predating both the isolation of thyroxine (1914) and the synthetic levothyroxine of the 1950s. Modern endocrinology guidelines prefer synthetic [[Levothyroxine]] as first-line replacement, but a residual population of patients and clinicians prefer desiccated thyroid for its T3 content and historical track record.

{{MedTemplate
| generic = Thyroid (desiccated)
| brand = Armour Thyroid, NP Thyroid, Nature-Throid, WP Thyroid
| structure =
| classes = [[:Category:Thyroid_hormones|Thyroid hormone]], [[:Category:Hormone_replacement|Hormone replacement]]
| uses = <vote slug="hypothyroidism-use">Hypothyroidism</vote>, <vote slug="goiter-use">Goiter</vote>
| starting_dose = 30 mg PO daily (1/2 grain); titrate by TSH at 6-8 weeks; 60 mg desiccated thyroid is approximately equivalent to 88-100 mcg levothyroxine
| preparations = 15, 30, 60, 90, 120, 180, 240, 300 mg tablets (1/4 to 5 grains; 1 grain = 60 mg)
| fda_max = No fixed maximum; titrated to TSH target
| pill_id =
| routes = Oral
| onset = TSH normalization 4-8 weeks
| duration = Steady-state at 4-6 weeks
| halflife = T4 ~7 days; T3 ~1 day<ref name="armour-label" />
| bioavailability = Variable; reduced by food, calcium, iron, PPIs<ref name="armour-label" />
| pregnancy = Synthetic levothyroxine is the standard-of-care in pregnancy; desiccated thyroid use in pregnancy is not well studied{{citation needed}}
| legal = [[USLegal:Prescription only|Rx-only]] in US
| mechanism = <vote slug="desiccated-thyroid-mech-claim">Desiccated thyroid supplies both T4 and T3 in a roughly 4:1 ratio; T4 is peripherally deiodinated to T3, but exogenous T3 supplementation produces faster onset and supraphysiologic post-dose peaks that synthetic T4 monotherapy avoids.</vote> Brand-to-brand and lot-to-lot variability in T3:T4 ratio is greater than with synthetic levothyroxine, which is why endocrine guidelines prefer the synthetic<ref name="armour-label" />.
}}

== References ==
<references />

Desiccated thyroid - Revision history

MDElliottMD: home-claude punt-list stub, Top 300 #141