TCS Industries Limited (China-sourced API supplier) supplies Liothyronine Sodium — API CAS 55-06-1 for pharmaceutical B2B procurement — COA, MSDS, and technical documentation available on request.
> Overview
| Product Name | Liothyronine Sodium |
|---|---|
| Structural Formula |  |
| CAS Number | 55-06-1 |
| Molecular Formula | C15H11I3NNaO4 |
| Molecular Weight | 672.95 g/mol |
| InChIKey | SBXXSUDPJJJJLC-YDALLXLXSA-M |
| SMILES | Available on request where applicable |
| Appearance | White to off-white crystalline powder |
| Purity / Grade | By agreed specification and batch COA |
| Storage | Store at controlled room temperature, protect from light and moisture |
Liothyronine Sodium (CAS 55-06-1) is the sodium salt of L-triiodothyronine (T3), a thyroid hormone with the formula C₁₅H₁₁I₃NNaO₄ (MW 672.96). T3 is the biologically active thyroid hormone, approximately 4–5 times more potent than levothyroxine (T4) on a weight basis. Liothyronine sodium is used for hypothyroidism, myxedema coma, and thyroid suppression testing.
TCS Industries Limited, a Hong Kong-based trading and sourcing company, supplies Liothyronine Sodium API in pharmaceutical grade for global procurement programs.
> Applications
Thyroid hormone replacement
Liothyronine sodium 5–50 μg/day is used for hypothyroidism when T3 replacement is specifically required, or in combination with levothyroxine. It has rapid onset (hours) and short duration (half-life ~1 day) compared to levothyroxine (half-life ~7 days). IV liothyronine is used for myxedema coma. Jonklaas et al. (Thyroid, 2014, 24:1670–1751) provided guidelines for hypothyroidism treatment including the role of liothyronine in T4/T3 combination therapy.
Diagnostic and adjunctive uses
Liothyronine is used in the T3 suppression test for thyroid autonomy assessment. It is also used short-term before radioiodine therapy for thyroid cancer (rapid T3 washout allows earlier RAI administration compared to T4 withdrawal). Compounded slow-release T3 preparations are used in some clinical settings.
> Sourcing & Supply
TCS Industries Limited supports development, qualification and commercial purchasing discussions for Liothyronine Sodium with buyers in Australia, New Zealand, Canada and South Korea.
- Evaluation and commercial quantities: 10 g samples for analytical qualification; 100 g and 500 g for production. Pharmaceutical (USP) grade. High-potency API — microgram dosing. DMF reference letters available.
- Pallet quantities and production campaigns: repeat supply is coordinated against packaging, lead time, annual demand and destination-market import requirements.
> Quality & Documentation
Key specification parameters include assay (≥95.0%), specific optical rotation, related substances (L-thyroxine, diiodothyronine), loss on drying, residual solvents, heavy metals, and microbial limits. White to off-white powder. Slightly soluble in water, soluble in dilute NaOH. Three iodine atoms per molecule (~56% iodine by weight). Identity by HPLC, IR, and specific optical rotation. Meets USP (Liothyronine Sodium) and Ph.Eur. COA and MSDS are standard.
> Packaging
Liothyronine sodium is a white to off-white powder, light-sensitive. High-potency API — handle with precision weighing equipment. Standard packaging includes amber glass bottles or sealed foil bags (10 g, 50 g, or 100 g). Store at controlled room temperature (15–25 °C). Protect from light and moisture. Shelf life is typically 24 months. Labels and documents are checked before dispatch.
> Pricing & MOQ
Pricing is quoted by specification, packaging and destination. Common commercial discussions use 25 kg bag/drum formats, pallet quantities and production-campaign planning; smaller samples may be reviewed for qualified formulation teams.
> Regulatory & Compounding Context
Liothyronine sodium is monographed in USP and Ph.Eur. FDA-approved (Cytomel, 1956). On the WHO Model List of Essential Medicines. Generic liothyronine tablets approved. High-potency API requiring precise dosing — narrow therapeutic index (NTI) drug. DMF support available from qualified manufacturers.
> Alias Index
- INN: Liothyronine
- CAS Number: 55-06-1 (sodium salt); 6893-02-3 (free acid, L-T3)
- Formula: C₁₅H₁₁I₃NNaO₄ (MW 672.96)
- Abbreviation: T3 (triiodothyronine)
- Brand name: Cytomel (Pfizer)
- ATC code: H03AA02
- Commercial request terms: liothyronine sodium API, T3 hormone bulk, Cytomel generic, thyroid hormone API, TCS Industries Limited
> FAQ
Why is T3 shorter-acting than T4?
T3 (liothyronine) has lower protein binding (~99.5% vs. 99.97% for T4), resulting in higher free fraction, faster cellular uptake, and faster clearance. Half-life is ~1 day (T3) vs. ~7 days (T4). This makes T3 less suitable for steady-state replacement but valuable when rapid onset or quick washout is needed.
What documents are available for Liothyronine Sodium orders?
COA and MSDS are standard for commercial discussions. COO, packing list, invoice and other import-support documents can be arranged according to order scope.
Do you supply Liothyronine Sodium to Australia and Canada?
Yes. We support B2B buyers in Australia, New Zealand, Canada and South Korea, subject to route and document review.
Do you supply New Zealand and South Korea?
Yes. We review Australia, New Zealand, Canada and South Korea for project supply, import documents, packaging and logistics planning before quotation.
Is T4/T3 combination therapy recommended?
Levothyroxine monotherapy is first-line for hypothyroidism. T4/T3 combination therapy is considered for patients with persistent symptoms despite normal TSH on T4 alone. ATA guidelines suggest trial of combination therapy in selected cases, with T4:T3 ratios of 13:1 to 20:1 to approximate physiological secretion ratios.
Why is microgram-level dosing precision needed?
Liothyronine tablets are dosed at 5–50 μg, making it a high-potency, narrow therapeutic index drug. Overdose causes thyrotoxicosis (tachycardia, tremor, weight loss). API manufacturing requires potency uniformity ≤2% deviation. Content uniformity testing of finished dosage forms is critical.
Can you arrange samples before commercial purchasing?
Samples or evaluation quantities may be reviewed for qualified buyers after target specification, application and destination-market requirements are clarified.
How is Liothyronine Sodium packaged for export?
Packaging is confirmed by quantity and material properties. Typical options include foil bags, HDPE containers, fibre drums, 25 kg bags or palletized export packaging.
Can buyer-defined specifications be reviewed?
Yes. Send the specification, methods, impurity limits and required documents. TCS can review feasibility before confirming quotation and lead time.
What payment terms are normally used?
Standard payment is 100% T/T before dispatch unless a different arrangement has been approved for an established commercial account.
What lead time should buyers expect?
Lead time depends on stock, batch size, document scope and destination. Available stock can move faster; made-to-order or pallet programs require longer planning.
Is a DMF available?
Yes. TCS sources liothyronine sodium from manufacturers who maintain active DMFs with the FDA and equivalent regulatory submissions. COA, stability data, and DMF reference letters are provided. High-potency API handling and containment capabilities are verified in manufacturer audits.
Last reviewed: June 2026
Evaluation and research orders (≤10 kg) are shipped with COA, MSDS, and certificate of origin. Bulk commercial orders (>10 kg) qualify for volume pricing with a full technical documentation package available on request.
> Request a Quote
If your team already has a target application, estimated quantity, destination market, or documentation requirements, send those details so the commercial response can be prepared more efficiently.