Rankings / Hormones & Endocrine
T4 / NDT (levothyroxine, desiccated thyroid)
Hormones & Endocrine · Thyroid hormone replacement
Tier B
Bottom line
Read Off Label grades T4 / NDT (levothyroxine, desiccated thyroid) as B (6.4/10) based on strong evidence, med benefit magnitude, and a med-risk safety profile.
Guidelines favor T4 monotherapy but NDT enjoys a dedicated following.
Typical use: T4: 1. — Rx.
What this is
Guidelines favor T4 monotherapy but NDT enjoys a dedicated following. Resistance to change may reflect imperfect T4→T3 deiodinase activity in subsets of patients (DIO2 polymorphism work). Generic levothyroxine is bioequivalent per FDA but brand consistency sometimes matters clinically. Take on empty stomach 30-60 min before food/supplements.
Mechanism
T4 = prohormone converted to T3 peripherally via deiodinases; standard hypothyroid therapy; NDT (Armour, NP Thyroid) provides porcine-derived T4+T3 in ~4:1 ratio
Dose & route
T4: 1.6 mcg/kg/day; NDT: 1 grain (60 mg) starting, titrate to TSH/symptoms
Citations
- https://pubmed.ncbi.nlm.nih.gov/25266247/
- https://pubmed.ncbi.nlm.nih.gov/19011087/
- https://pmc.ncbi.nlm.nih.gov/articles/PMC5785757/
- https://pubmed.ncbi.nlm.nih.gov/34457140/
- https://pubmed.ncbi.nlm.nih.gov/38260143/
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Common questions
- Does T4 / NDT (levothyroxine, desiccated thyroid) work?
- Read Off Label rates the evidence for T4 / NDT (levothyroxine, desiccated thyroid) as Strong and the benefit magnitude as med, producing an overall grade of B (6.4/10). Guidelines favor T4 monotherapy but NDT enjoys a dedicated following.
- Is T4 / NDT (levothyroxine, desiccated thyroid) safe?
- T4 / NDT (levothyroxine, desiccated thyroid) has a med risk profile in published human data. Legal status: Rx. This is not medical advice — see the disclaimer.
- What is the typical dose for T4 / NDT (levothyroxine, desiccated thyroid)?
- T4: 1.6 mcg/kg/day; NDT: 1 grain (60 mg) starting, titrate to TSH/symptoms
- How does T4 / NDT (levothyroxine, desiccated thyroid) work?
- T4 = prohormone converted to T3 peripherally via deiodinases; standard hypothyroid therapy; NDT (Armour, NP Thyroid) provides porcine-derived T4+T3 in ~4:1 ratio
This is an independent synthesis of published research by a non-clinician. Scores are opinions supported by citations, not prescriptions. See the full disclaimer and methodology for how this score was produced and what it does and doesn't mean.