Molekula
L-Thyroxine
Supplying 4,500+ customers in over 80 countries
ISO 9001:2015 & ISO 14001:2015 certified · Supplying laboratories and industry since 1999 · Listed pack sizes are a starting point — we manufacture, source and repack to the quantity you need
L-Thyroxine is a synthetic thyroid hormone used in the treatment of hypothyroidism and thyroid cancer. It is a key compound in regulating metabolism and is available in various forms for medical and research applications. CAS: 51-48-9, Molecular Formula: C15H11I4NO4, Molecular Weight: 776.87 g/mol, Storage: Ambient, Signal Word: Danger.
Molekula supplies L-Thyroxine at 98.0 -102.0 % purity in 1 g packs, from £42.96 inc. VAT. It is in stock for same-day dispatch. Every batch ships with a certificate of analysis, and safety data sheets are available in 5 languages. Larger quantities, up to multi-tonne, are quoted on request.
Example image for illustration only. Other packaging and pack sizes are available.
Pricing & pack sizes
In stock — same-day dispatch
These pack sizes aren't a limit. Molekula manufactures, sources and repacks to order — if you need 500 kg and only see 1 kg listed, . We quote from grams to multi-tonne.
Need a different size? Add the nearest pack and change the size in your basket — we price it at the same rate per unit.
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1 g — £35.80 per pack ex VAT · £42.96 inc. VAT
Need a different quantity or pack?
Tell us how much you need and when — drums, IBCs, sacks or a one-off bulk lot. We'll manufacture or source it and come back with a price.
Prices exclude VAT/sales tax and shipping.
Specifications
| Property | Value |
|---|---|
| Appearance | Off-white to cream coloured powder |
| Specific rotation | -6.0 - -5.0° |
| Loss on Drying | 0.0 to 11.0 % |
| Purity | 98.0 -102.0 % |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | Ambient |
| Acidity | Neutral |
Literature values
Published physical properties of the substance, not batch specifications.
| Property | Value |
|---|---|
| Appearance | Needles |
| Melting Point | 235.5 °C |
| Water Solubility | Slightly soluble in water |
Source: PubChem CID 5819 (HSDB, DrugBank)
Identification
| Property | Value |
|---|---|
| SKU | 25797978 |
| CAS Number | 51-48-9 |
| IUPAC Name | (2S)-2-amino-3-[4-(4-hydroxy-3,5-diiodophenoxy)-3,5-diiodophenyl]propanoic acid |
| EC Number | 200-101-1 |
| Molecular Formula | C15H11I4NO4 |
| Molecular Weight | 776.87 |
| Exact Mass | 776.6867 |
| SMILES | C1=C(C=C(C(=C1I)OC2=CC(=C(C(=C2)I)O)I)I)C[C@@H](C(=O)O)N |
| InChIKey | XUIIKFGFIJCVMT-LBPRGKRZSA-N |
| InChI | InChI=1S/C15H11I4NO4/c16-8-4-7(5-9(17)13(8)21)24-14-10(18)1-6(2-11(14)19)3-12(20)15(22)23/h1-2,4-5,12,21H,3,20H2,(H,22,23)/t12-/m0/s1 |
| PubChem CID | 5819 |
| REACH Code | Y110 |
| TSCA Listed | Yes |
| HTS Code | 29379045 |
| Tariff Code | 2937900000 |
Safety & GHS
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Health Hazard
GHS07
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Serious Health Hazard
GHS08
Hazard statements
- H302 Harmful if swallowed
- H370 Causes damage to organs
- H372 Causes damage to organs through prolonged or repeated exposure
Precautionary statements
- P202 Do not handle until all safety precautions have been read and understood
- P260 Do not breathe dust/fume/gas/mist/vapours/spray
- P280 Wear protective gloves/protective clothing/eye protection/face protection
- P301+312 IF SWALLOWED: Call a POISON CENTER or doctor/physician if you feel unwell
- P308+313 IF exposed or concerned: Get medical advice/attention
Documents
Safety Data Sheets (SDS)
Available in English, French, German, Italian, Spanish.
Certificate of Analysis (CoA) by batch
Enter a lot or batch number to retrieve the CoA for that specific batch. We can generate one from spec data if no PDF is on file.
Quality certificates
Molekula Group is certified to ISO 9001:2015 (quality) and ISO 14001:2015 (environmental management), audited by a UKAS-accredited body. Both certificates are valid to 17 May 2028.
Synonyms
- 2-amino-3-(4-(4-hydroxy-3,5-diiodophenoxy)-3,5-diiodophenyl)propanoic acid
- L Thyrox
- L Thyroxin beta
- L Thyroxin Henning
- L Thyroxine Roche
- L-3,5,5'-tetraiodothyronine
- Levothyroxin Delalande
- thyroxin
- thyroxine
- Tyrosine, O-(4-hydroxy-3,5-diiodophenyl)-3,5-diiodo-
Frequently asked questions
What is L-Thyroxine used for?
L-Thyroxine is primarily used in the treatment of hypothyroidism and thyroid cancer. It is also used in research and diagnostic applications.
What is the chemical formula and molecular weight of L-Thyroxine?
The formula is C15H11I4NO4 with a molecular weight of 776.87 g/mol.
How should L-Thyroxine be stored?
Store at ambient temperature, protected from light and moisture.
What grade of L-Thyroxine does Molekula supply?
Molekula supplies L-Thyroxine as an off-white to cream coloured powder with a purity of 98.0–102.0 %, a specific rotation of -6.0 to -5.0° and a loss on drying of 0.0 to 11.0 %.
Can Molekula supply L-Thyroxine in bulk?
Yes, Molekula can supply L-Thyroxine in bulk quantities—please contact us for pricing and availability.
What documentation comes with an order of L-Thyroxine?
Each order includes a Certificate of Analysis and Safety Data Sheet (SDS) with the shipment.
Where can I buy L-Thyroxine?
Directly from Molekula, which lists L-Thyroxine in 1 g packs from £42.96 inc. VAT, with a certificate of analysis for every batch. Larger quantities are quoted on request. Molekula's offices: United Kingdom, France, Spain, Germany, Italy, United States and China.
Ready to order or need a custom pack?
Tell us the product, grade, and quantity — Molekula usually responds within one working day with pricing and lead time.