Molekula
L-Cystine
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-Cystine is a disulfide-bonded dimer of the amino acid L-cysteine, used in biochemical research, cell culture media, and pharmaceutical formulations for its role in protein structure and antioxidant activity. In food manufacturing it serves as a flour treatment agent and dough strengthener, a flavoring agent and a nutritional supplement, and it is also used as a cosmetic ingredient. It has a CAS number of 56-89-3, molecular formula [-SCH2CH(NH2)CO2H]2, and a molecular weight of 240.30 g/mol. Stable at ambient storage conditions. Molekula supplies L-Cystine from research to bulk quantities with full documentation and ISO 9001:2015 traceability.
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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100 g — £36.40 per pack ex VAT · £43.68 inc. VAT
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1 kg — £108.90 per pack ex VAT · £130.68 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 | White crystals or crystalline powder |
| Specific rotation | -215° to -225° |
| Heavy metals | ≤ 0.0015% |
| Loss on Drying | ≤ 0.20% |
| Chloride (Cl-) | ≤ 0.10% |
| Assay | 98.5% to 101.5% |
| Residue on Ignition | ≤ 0.10% |
| Particle Size | Approx 80 mesh/ 165 micron. |
| Iron (Fe) | ≤ 0.003% |
| Arsenic (As) | ≤ 1.5ppm |
| Sulphates (SO4)(2-) | ≤ 0.040% |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | Ambient |
| Acidity | Neutral |
Literature values
Published physical properties of the substance, not batch specifications.
| Property | Value |
|---|---|
| Melting Point | 260.5 °C |
| pKa | pKa = 1 |
Source: PubChem CID 67678 (Human Metabolome Database (HMDB), DrugBank)
Identification
| Property | Value |
|---|---|
| SKU | 11394887 |
| CAS Number | 56-89-3 |
| IUPAC Name | (2R)-2-amino-3-[[(2R)-2-amino-2-carboxyethyl]disulfanyl]propanoic acid |
| EC Number | 200-296-3 |
| Molecular Formula | [-SCH2CH(NH2)CO2H]2 |
| Molecular Weight | 240.30 |
| Exact Mass | 240.0238 |
| SMILES | C([C@@H](C(=O)O)N)SSC[C@@H](C(=O)O)N |
| InChIKey | LEVWYRKDKASIDU-IMJSIDKUSA-N |
| InChI | InChI=1S/C6H12N2O4S2/c7-3(5(9)10)1-13-14-2-4(8)6(11)12/h3-4H,1-2,7-8H2,(H,9,10)(H,11,12)/t3-,4-/m0/s1 |
| PubChem CID | 67678 |
| REACH Code | Y113 |
| TSCA Listed | Yes |
| HTS Code | 29309092 |
| Tariff Code | 2930901300 |
Safety & GHS
Detailed safety information available in the SDS — see Documents below.
Documents
Safety Data Sheets (SDS)
Available in English, French, German, Italian, Russian, 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
- 1-Cystine
- beta,beta'-Dithiodialanine
- Cysteine disulfide
- Cystin
- cystine
- Cystine acid
- Cystine, L-
- Dicysteine
- L-Cysteine disulfide
- L-Dicysteine
Frequently asked questions
What is L-Cystine used for?
L-Cystine is primarily used in pharmaceuticals, cosmetics, and dietary supplements for its role in protein synthesis and antioxidant properties.
What is the chemical formula and molecular weight of L-Cystine?
The formula is [-SCH2CH(NH2)CO2H]2 and the molecular weight is 240.30 g/mol.
How should L-Cystine be stored?
Store at ambient temperature, protected from moisture and light.
What grade of L-Cystine does Molekula supply?
Molekula supplies L-Cystine in pharmaceutical grade.
Can Molekula supply L-Cystine in bulk?
Yes, Molekula can supply L-Cystine in bulk quantities upon request.
What documentation comes with an order of L-Cystine?
Each order includes a Certificate of Analysis (CoA) and Safety Data Sheet (SDS).
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.