L-Methionine
L-Methionine is the natural L-isomer of methionine, an essential sulphur-containing amino acid required for protein synthesis and one-carbon metabolism in humans and animals.
The molecule carries a thioether side chain that makes it the primary biological methyl donor through its activated form S-adenosyl-L-methionine (SAMe). It also feeds the trans-sulfuration pathway that produces cysteine, taurine, and glutathione.
We source bulk L-Methionine from top China manufacturers for our partners, working with several of them. The manufacturers are in Hebei and Jiangsu. A smaller requirement can ship in a combined container with other ingredients.
Please send the grade you need, the volume and your destination port, and we will come back with a solution and a price.
or call +86-21-6858 0751
- Packaging
- 25 kg kraft paper bag with PE inner liner
- ISO 9001
- HACCP
- Halal
- Kosher
Specifications
| Item | Specification |
|---|---|
| Appearance | White crystalline powder with a faint characteristic sulphur odour |
| Assay (dried basis) | 98.5-101.0% |
| Specific Rotation [α]D20 | +22.5° to +24.5° (c=2, 6 mol/L HCl) |
| Loss on Drying | ≤ 0.3% |
| Residue on Ignition | ≤ 0.1% |
| pH (1% solution) | 5.6-6.1 |
| Chloride (as Cl) | ≤ 0.02% |
| Sulfate (as SO₄) | ≤ 0.03% |
| Iron | ≤ 10 mg/kg |
| Other Amino Acids (TLC) | Conforms |
| Heavy Metals (as Pb) | ≤ 10 mg/kg |
| Lead | ≤ 1 mg/kg |
| Arsenic | ≤ 1 mg/kg |
| Total Plate Count | ≤ 1000 CFU/g |
| Salmonella | Negative/25g |
Common Markets Grades
L-Methionine is a white crystalline powder with a faint characteristic sulphur odour.
Pharmaceutical grade meets USP, Ph. Eur., and JP monographs at 98.5 to 101.0 percent assay on a dried basis. It is used in injectable amino acid solutions, oral pharmaceuticals, and parenteral nutrition.
Food and nutritional grade at 99 percent minimum assay covers infant formula fortification, medical foods, and dietary supplements. Specifications track residue on ignition, heavy metals, and microbial counts under FCC.
Feed grade L-methionine at 99 percent is produced for premium aquaculture and pet food where the single L-isomer is preferred over the racemic DL form.
Applications
- Infant and follow-on formula as a mandated essential amino acid
- Total parenteral nutrition (TPN) and amino acid infusion bags
- Oral hepatoprotective preparations and SAMe precursor supplements
- Sports nutrition and bodybuilding protein blends
- Medical foods for phenylketonuria and other metabolic disorders
- Dietary supplements positioned for hair, skin, and nail support
- Veterinary injectables and oral pet supplements
- Premium aquaculture feeds for salmonids and shrimp larviculture
- Cell culture media and fermentation feedstocks
- Cosmetic actives in hair-care serums and shampoos
Brands Using L-Methionine
Widely-distributed consumer products that list L-Methionine on the ingredient label.
- NOW FoodsL-Methionine 500 mg Capsules ↗Official NOW Foods product page lists 'L-Methionine (Free-Form) 500 mg' per capsule plus Vitamin B-6; other ingredients include hypromellose (cellulose capsule), stearic acid (vegetable source) and silicon dioxide.Label verified 2026-05-24
- SolgarSolgar L-Methionine 500 mg Vegetable Capsules ↗Solgar L-Methionine 500 mg supplement facts panel lists free-form L-Methionine as the active ingredient; other ingredients are vegetable cellulose, silica and vegetable magnesium stearate.Label verified 2026-05-24
- Pure Encapsulationsl-Methionine ↗Capsules listing free-form L-methionine as the active amino acid, in a vegetarian capsule of cellulose and water.Label verified 2026-05-24
Brand names, product names and logos are the property of their owners. They appear here as published evidence that the ingredient is used, taken from the brand's own label or website. Their appearance is not an endorsement, and it does not mean the brand buys from us or from any manufacturer listed on this site.
China Manufacturers of L-Methionine
Top L-Methionine manufacturers in China.
Hebei Changhao Biotechnology Co., Ltd.10 ingredients in the directory
Hebei Huafan Biological Technology Co., Ltd.15 ingredients in the directory
Jiangsu Quanjia Shun Health Technology Co., Ltd.12 ingredients in the directory
Shijiazhuang Haitian Amino Acid Co., Ltd.11 ingredients in the directory
Company names and logos are the property of the manufacturers themselves. They are listed here because our own directory records them as producing this ingredient. A listing is not an endorsement by them, and we do not represent them or speak on their behalf.
How We Help Source L-Methionine
Direct Factory Sourcing
We run the whole process: selecting the manufacturer from the top Chinese food ingredient producers, negotiating the price, verifying quality, and coordinating the logistics. You deal with us instead of with several factories at once.
Original Packaging and Documents from the Manufacturer
The manufacturer sends your L-Methionine out of its own factory in the original packing, through to your destination port. The COA, COO, MSDS, TDS and any certifications reach you from the manufacturer as well.
Free Samples and Lead Time
We send 100 to 500 g free for your own laboratory to test and you cover only the courier, usually within 2 to 3 working days. ETD is usually within 7 to 15 days once the order is confirmed, and we check that date against the factory's own manufacturing schedule before we give it to you.
Combined Shipment
We can load L-Methionine together with other ingredients such as Glycine, L-Arginine and L-Leucine into one 20' FCL. If your quantity is small, we can also ship LCL.
Regulatory Status
L-Methionine is recognised worldwide as an essential nutrient and approved for use in foods, medical nutrition, and pharmaceuticals.
In the United States it is GRAS under 21 CFR 172.320 as a nutrient that may be added to foods, with specific provisions for infant formula under 21 CFR 107. The European Union authorises L-methionine for general food use and as a permitted source of the amino acid in food supplements under Directive 2002/46/EC.
JECFA has reviewed L-methionine and classified it as acceptable for use as a nutrient without numerical limit when used in line with good manufacturing practice. Codex Alimentarius lists it in the infant formula standard CODEX STAN 72-1981.
USP, Ph. Eur., and JP monographs govern pharmaceutical use. Kosher and Halal certifications are routinely available from fermentation producers.
Manufacturing Process
Industrial L-methionine is produced almost exclusively by microbial fermentation.
Engineered strains of Escherichia coli and Corynebacterium glutamicum convert glucose or sucrose into L-methionine through the aspartate pathway, with metabolic engineering used to overcome the strong feedback regulation by SAMe. CJ CheilJedang in South Korea operates the largest dedicated L-methionine fermentation capacity, with Meihua and other Asian producers contributing additional volume.
A secondary route resolves DL-methionine by acylation with acetic anhydride, followed by enzymatic hydrolysis with porcine kidney acylase or microbial acylase to release the L-isomer while leaving the N-acetyl-D-methionine for racemization and recycling.
Downstream processing follows standard amino acid recovery: cell separation, ion exchange, decolorisation with activated carbon, crystallisation, centrifugation, and drying to yield the finished crystalline powder.
