Molekula
L-Tryptophan
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-Tryptophan is an essential amino acid used in nutritional supplements, pharmaceuticals, and research. It serves as a precursor to serotonin and melatonin, supporting mood and sleep regulation. Available in powder form, it has a CAS number of 73-22-3, molecular formula C11H12N2O2, and a molecular weight of 204.23 g/mol. Stable at ambient storage conditions.
Molekula supplies L-Tryptophan at ≥ 98.5% purity in 100 g, 500 g and 1 kg packs, from £102.00 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 6 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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100 g — £85.00 per pack ex VAT · £102.00 inc. VAT
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500 g — £195.00 per pack ex VAT · £234.00 inc. VAT
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1 kg — £280.00 per pack ex VAT · £336.00 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 Powder |
| Specific rotation | -29.4 to -32.8 |
| Identification | Conforms to reference |
| pH | 5.5 to 7.0 |
| Loss on Drying | ≤ 0.3% |
| Specification | Conforms to USP specification |
| Chloride (Cl-) | ≤ 0.05% |
| Assay | ≥ 98.5% |
| Residue on Ignition | ≤ 0.1% |
| Iron (Fe) | ≤ 0.003% |
| Lead (Pb) | ≤ 0.0015% |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | Ambient |
| Acidity | Neutral |
Literature values
Published physical properties of the substance, not batch specifications.
| Property | Value |
|---|---|
| Odour | Odorless |
| Melting Point | 282 °C (decomposes) |
| Solubility (other solvents) | Slightly soluble in acetic acid, ethanol; insoluble in ethyl ether |
| pKa | pKa = 7.38 (at 25 °C) |
| log P (octanol/water) | -1.06 |
Source: PubChem CID 6305 (HSDB, DrugBank)
Identification
| Property | Value |
|---|---|
| SKU | 13831082 |
| CAS Number | 73-22-3 |
| IUPAC Name | (2S)-2-amino-3-(1H-indol-3-yl)propanoic acid |
| EC Number | 200-795-6 |
| Molecular Formula | C11H12N2O2 |
| Molecular Weight | 204.23 |
| Exact Mass | 204.0899 |
| SMILES | C1=CC=C2C(=C1)C(=CN2)C[C@@H](C(=O)O)N |
| InChIKey | QIVBCDIJIAJPQS-VIFPVBQESA-N |
| InChI | InChI=1S/C11H12N2O2/c12-9(11(14)15)5-7-6-13-10-4-2-1-3-8(7)10/h1-4,6,9,13H,5,12H2,(H,14,15)/t9-/m0/s1 |
| PubChem CID | 6305 |
| REACH Code | Y113 |
| TSCA Listed | Yes |
| HTS Code | 29339975 |
| Tariff Code | 2933998090 |
Safety & GHS
Precautionary statements
- P264 Wash thoroughly after handling
- P280 Wear protective gloves/protective clothing/eye protection/face protection
- P308+313 IF exposed or concerned: Get medical advice/attention
Documents
Safety Data Sheets (SDS)
Available in English, French, German, Italian, Portuguese, 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
- (2S)-2-amino-3-(1H-indol-3-yl)propanoic acid
- (S)-Tryptophan
- Ardeytropin
- Indole-3-alanine
- L-Tryptophane
- Pacitron
- trofan
- tryptacin
- tryptophan
- Tryptophane
Frequently asked questions
What is L-Tryptophan used for?
L-Tryptophan is primarily used as a dietary supplement and in the synthesis of serotonin and melatonin, supporting mood regulation and sleep cycles.
What is the chemical formula and molecular weight of L-Tryptophan?
The formula is C11H12N2O2 with a molecular weight of 204.23 g/mol.
How should L-Tryptophan be stored?
Store at ambient temperature, protected from moisture and light.
What grade of L-Tryptophan does Molekula supply?
Molekula supplies L-Tryptophan in pharmaceutical and research grade.
Can Molekula supply L-Tryptophan in bulk?
Yes, Molekula can supply L-Tryptophan in bulk quantities; please contact sales for details.
What documentation comes with an order of L-Tryptophan?
Each order includes a Certificate of Analysis (CoA) and Safety Data Sheet (SDS).
Where can I buy L-Tryptophan?
Directly from Molekula, which lists L-Tryptophan in 100 g, 500 g and 1 kg packs from £102.00 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.