L-Methionine API Manufacturers & Suppliers
6 verified results
Commercial-scale Suppliers
All certificates
All certificates
All certificates
All certificates
All certificates
All certificates







Methionine | CAS No: 63-68-3 | GMP-certified suppliers
A medication that supports nutritional and metabolic needs by providing essential amino acid supplementation and serves as an adjunct option in managing acetaminophen overdose.
Therapeutic categories
Primary indications
- Used for protein synthesis including the formation of SAMe, L-homocysteine, L-cysteine, taurine, and sulfate
Product Snapshot
- Methionine is supplied as an oral small‑molecule amino acid and as parenteral solution formulations, including multiple injectable presentations
- It is used as a metabolic precursor to support protein synthesis pathways and related sulfur‑containing compound formation
- It is available in the US and Canada with classifications ranging from approved drug products to nutraceutical status
Clinical Overview
Clinically, methionine is employed when exogenous supply is needed to maintain normal protein synthesis and sulfur-dependent metabolic pathways. Additional medical use includes its role as an adjunct in acetaminophen overdose protocols in some settings, where it serves as an alternative precursor for enhancing cysteine and subsequent glutathione availability.
Pharmacologically, methionine provides a source of organic sulfur and participates in methylation reactions through conversion to S‑adenosylmethionine. It exhibits chelating capacity for certain heavy metals. Reported biological effects include modulation of sulfur metabolism, contribution to hepatic lipid handling, and support of renal ammonia detoxification pathways, though these effects depend on nutritional and physiological status.
The mechanism related to protection against hepatotoxicity is attributed to its role as a precursor of cysteine and glutathione. Enhanced glutathione synthesis can support cellular redox balance under conditions of increased oxidative stress. Methionine itself also shows free radical scavenging activity related to its sulfur moiety.
Absorption occurs through active transport in the gastrointestinal tract, followed by wide systemic distribution and incorporation into proteins or metabolic pathways. Methionine undergoes trans-sulfuration and transmethylation reactions, with metabolites entering one‑carbon and sulfur metabolic cycles.
Safety considerations include the potential for elevated homocysteine concentrations with excessive intake, and caution is warranted in individuals with disorders of sulfur amino acid metabolism. Use in children or pregnant individuals requires adherence to established clinical guidance.
For API procurement, sourcing should focus on verified identity, control of stereochemical purity for the L‑isomer, and compliance with pharmacopeial specifications regarding residual solvents, heavy metals, and microbial quality.
Identification & chemistry
| Generic name | Methionine |
|---|---|
| Molecule type | Small molecule |
| CAS | 63-68-3 |
| UNII | AE28F7PNPL |
| DrugBank ID | DB00134 |
Pharmacology
| Summary | L‑methionine functions primarily as an essential sulfur‑containing amino acid supporting biosynthesis of cysteine and glutathione, contributing to cellular redox balance. Its proposed hepatoprotective activity is linked to antioxidant and free‑radical–scavenging properties of methionine and its metabolites during oxidative stress. Key metabolic targets include enzymes involved in methionine cycling and methylation pathways, such as methionine synthase, methionine synthase reductase, and betaine‑homocysteine S‑methyltransferases. |
|---|---|
| Mechanism of action | The mechanism of the possible anti-hepatotoxic activity of L-methionine is not entirely clear. It is thought that metabolism of high doses of acetaminophen in the liver lead to decreased levels of hepatic glutathione and increased oxidative stress. L-methionine is a precursor to L-cysteine. L-cysteine itself may have antioxidant activity. L-cysteine is also a precursor to the antioxidant glutathione. Antioxidant activity of L-methionine and metabolites of L-methionine appear to account for its possible anti-hepatotoxic activity. Recent research suggests that methionine itself has free-radical scavenging activity by virtue of its sulfur, as well as its chelating ability. |
| Pharmacodynamics | L-Methionine is a principle supplier of sulfur which prevents disorders of the hair, skin and nails; helps lower cholesterol levels by increasing the liver's production of lecithin; reduces liver fat and protects the kidneys; a natural chelating agent for heavy metals; regulates the formation of ammonia and creates ammonia-free urine which reduces bladder irritation; influences hair follicles and promotes hair growth. L-methionine may protect against the toxic effects of hepatotoxins, such as acetaminophen. Methionine may have antioxidant activity. |
Targets
| Target | Organism | Actions |
|---|---|---|
| Methionine synthase reductase | Humans | product of |
| Methionine synthase | Humans | product of |
| Methionine aminopeptidase 2 | Humans | product of |
ADME / PK
| Absorption | Absorbed from the lumen of the small intestine into the enterocytes by an active transport process. |
|---|---|
| Metabolism | Hepatic |
Formulation & handling
- Oral forms are straightforward to formulate due to high aqueous solubility, with food taken alongside to support GI tolerance.
- Parenteral and intraperitoneal solutions require attention to pH and oxidation control, as sulfur‑containing amino acids are prone to oxidative degradation.
- Topical and emulsion preparations should ensure chemical stability of the free amino acid in aqueous systems and avoid exposure to strong oxidizing conditions during handling.
Regulatory status
| Lifecycle | Patent expiry in the US and Canada typically marks the transition of the API from protected to competitive markets, signaling maturation of the product lifecycle. As generic entrants expand in these regions following expiry, market dynamics generally shift toward established, price‑driven competition. |
|---|
| Markets | Canada, US |
|---|
Supply Chain
| Supply chain summary | Methionine used in parenteral nutrition is supplied as a mature commodity ingredient, with packagers such as Amend and Spectrum Pharmaceuticals supporting distribution in the US and Canada. Branded parenteral nutrition formulations containing methionine are available across these markets, indicating established global use rather than reliance on a single originator. As a basic amino acid with no active patent protections, the ingredient already functions in an open, fully generic supply environment. |
|---|
Safety
| Toxicity | Doses of L-methionine of up to 250 mg daily are generally well tolerated. Higher doses may cause nausea, vomiting and headache. Healthy adults taking 8 grams of L-methionine daily for four days were found to have reduced serum folate levels and leucocytosis. Healthy adults taking 13.9 grams of L-methionine daily for five days were found to have changes in serum pH and potassium and increased urinary calcium excretion. Schizophrenic patients given 10 to 20 grams of L-methionine daily for two weeks developed functional psychoses. Single doses of 8 grams precipitated encephalopathy in patients with cirrhosis. |
|---|
- High oral loads (≥8 g/day) have been associated with metabolic disturbances, including reduced serum folate, altered serum pH and potassium, and increased urinary calcium excretion
- Very high exposures (10–20 g/day) have produced neuropsychiatric effects such as functional psychoses in susceptible populations
- Single 8‑g doses have triggered encephalopathy in individuals with cirrhosis
L-Methionine is a type of Amino acids
Amino acids are an essential category of pharmaceutical active pharmaceutical ingredients (APIs) widely used in the pharmaceutical industry. These organic compounds are the building blocks of proteins and play a crucial role in various biological processes. With their increasing popularity and therapeutic potential, amino acids have become a focus of research and development in drug discovery.
Amino acids can be classified into two main categories: essential and non-essential. Essential amino acids cannot be synthesized by the body and must be obtained from dietary sources or through pharmaceutical supplementation. Non-essential amino acids, on the other hand, can be synthesized by the body itself.
Pharmaceutical-grade amino acids are produced through a variety of methods, including extraction from natural sources, fermentation, and chemical synthesis. They undergo rigorous quality control procedures to ensure purity, efficacy, and safety. The most common amino acids used as APIs include lysine, valine, leucine, isoleucine, phenylalanine, and methionine, among others.
Amino acids have diverse applications in the pharmaceutical industry. They are widely used as ingredients in parenteral nutrition formulations, where they provide essential nutrients to patients who cannot consume food orally. Additionally, amino acids are utilized in the development of protein-based drugs, such as monoclonal antibodies and recombinant proteins. These pharmaceutical proteins often require specific amino acid sequences to achieve desired therapeutic effects.
In conclusion, amino acids are a vital category of pharmaceutical APIs, playing a significant role in protein synthesis, nutrition, and the development of protein-based drugs. With their extensive applications and growing demand, amino acids continue to contribute to advancements in the pharmaceutical industry.
L-Methionine API manufacturers & distributors
Compare qualified L-Methionine API suppliers worldwide. We currently have 6 companies offering L-Methionine API, with manufacturing taking place in 4 different countries. Use the table below to review supplier type, countries of origin, certifications, product portfolio and GMP audit availability.
| Supplier | Type | Country | Product origin | Certifications | Portfolio |
|---|---|---|---|---|---|
| Amino GmbH | Producer | Germany | Germany | CoA, GMP | 17 products |
| Changzhou Comwin Fine Che... | Producer | China | China | BSE/TSE, CoA, GMP, ISO9001, MSDS, USDMF, WC | 235 products |
| Evonik Rexim | Producer | China | Unknown | CEP, CoA, GMP, JDMF, USDMF, WC | 18 products |
| Sekisui Medical | Producer | Japan | Japan | CEP, CoA, GMP, JDMF, USDMF | 11 products |
| Senova Technology Co., Lt... | Producer | China | China | CoA, GMP, ISO9001, USDMF | 157 products |
| Wuhan Amino Acid Bio-Chem... | Producer | China | China | CoA | 32 products |
When sending a request, specify which L-Methionine API quality you need: for example EP (Ph. Eur.), USP, JP, BP, or another pharmacopoeial standard, as well as the required grade (base, salt, micronised, specific purity, etc.).
Use the list above to find high-quality L-Methionine API suppliers. For example, you can select GMP, FDA or ISO certified suppliers. Visit our help page to learn more about sourcing APIs via Pharmaoffer.
