What is T3 (Liothyronine)?
T3 (Liothyronine / Triiodothyronine) is the biologically active thyroid hormone — the form that directly binds thyroid receptors (TRα/TRβ) with ~10× higher affinity than T4. Unlike T4, T3 does not require deiodination and acts immediately at the receptor level to regulate basal metabolic rate, thermogenesis, cardiac contractility, and gene expression. Research tool for thyroid receptor pharmacology, metabolic rate modulation, HPT axis feedback, and T3 vs T4 direct comparison studies. Research use only.
Research Applications
Direct TR Agonism
TRα/TRβ binding, TRRE-mediated transcription — no deiodination step required vs T4
Metabolic Rate Research
Rapid basal metabolic rate upregulation, thermogenesis, oxygen consumption rate
T3 vs T4 Comparison
Direct receptor agonist vs prohormone — onset, potency, TR affinity, duration
HPT Axis Research
TSH suppression via negative feedback, TRH regulation, pituitary T3 sensitivity
Cardiac Thyroid Research
TRα-mediated chronotropy, myosin heavy chain isoform switching, cardiac gene expression
Quick Specs
| Form | C₁₅H₁₂I₃NO₄, MW 650.98 |
| Purity | ≥99% by HPLC — every batch |
| CAS Number | 6893-02-3 |
| Molecular Weight | MS molecular weight confirmed — every batch |
| Specification | ≥99% by HPLC — every batch |
| Shelf Life | 24 months (unopened) |
| Storage | Room temperature sealed | cool, dry storage |
| Manufacture | In-house synthesis — Qingdao, China |
| Brand | China |