L-aspartic acid
L-aspartic acid suppliers and sourcing guide
L-aspartic acid is a non-essential, acidic amino acid. Commercial L-aspartic acid is made enzymatically from fumaric acid and ammonia using the enzyme aspartase, often in immobilized bacterial cells, then crystallized. It is a white crystalline powder that is only slightly soluble in water. Brands buy it for amino acid blends and as a raw material for mineral aspartates, and it is also a feedstock for aspartame.
- Category
- Proteins and amino acids
- Also known as
- Aspartic acid · L-Asp · (S)-Aminobutanedioic acid · Aminosuccinic acid
- Facts checked
- November 2026
Forms and grades of L-aspartic acid
Suppliers sell different products under the same name. Specify the one you need.
Crystalline
Standard fine crystalline powder for capsules, tablets and dry blends.
Food grade
L-aspartic acid tested to a Food Chemicals Codex or supplier food specification for use in foods and drink mixes.
USP grade
L-aspartic acid tested to the USP monograph, used where a compendial grade is required for supplements.
Mineral aspartates
Salts such as potassium aspartate and magnesium aspartate, sold as separate ingredients; calculate both the mineral and the aspartate content from the salt.
What to check on the COA
Compare each result with your own specification when the lot arrives.
- Identity
- Infrared spectrum matched to a reference standard, plus specific optical rotation, which confirms the L-form of aspartic acid.
- Assay
- Purity on a dried basis by titration or HPLC, reported against the USP, FCC or supplier specification.
- Related substances
- Other amino acids and residual fumaric or maleic acid by HPLC.
- Loss on drying and residue on ignition
- Moisture by loss on drying and inorganic residue as residue on ignition (sulfated ash), with chloride and sulfate where the specification lists them.
- Heavy metals and microbiology
- Lead, arsenic, cadmium and mercury by ICP-MS, plus total plate count, yeast and mold, E. coli and Salmonella.
Storage, lots and expiry
Storage and shelf life
Store L-aspartic acid in tightly closed, lined containers in a cool, dry place away from light and strong odors, and reseal opened packs promptly. Shelf life or retest date is set by the supplier's specification; assay, loss on drying and micro are the usual retest points for older stock.
Lots and expiry dates
Record assay and grade for each lot. Rotate stock FEFO.
Regulatory status
Facts from regulators and standards bodies, each linked to its source.
21 CFR 172.320 lists L-aspartic acid among the amino acids that may be safely used as nutrients added to foods.
Source: ecfr.gov (opens in a new tab)Under 21 CFR 172.320, added plus naturally present L-aspartic acid, including L-asparagine, may not exceed 7.0 percent by weight of the total protein of the finished food.
Source: ecfr.gov (opens in a new tab)FDA's Substances Added to Food inventory lists L-aspartic acid with the technical effects flavor enhancer, flavoring agent or adjuvant, and nutrient supplement.
Source: hfpappexternal.fda.gov (opens in a new tab)Health Canada's Workout Supplements monograph lists L-aspartic acid among its non-essential amino acids, with potassium aspartate and potassium magnesium aspartate as source ingredients and a dose range of 325 mg to 1 g per day.
Source: webprod.hc-sc.gc.ca (opens in a new tab)
This is general information, not regulatory advice. Status differs by country and by how the ingredient is used, so check the rules for your product and market.
L-aspartic acid suppliers
Manufacturers and distributors whose own websites say they sell it.
We are checking L-aspartic acid suppliers now
Every listing is checked against the supplier’s own website before it goes live, so this list fills in over the coming weeks. The specs and COA checklist above are ready today.
Sell L-aspartic acid? Request a listingFrequently asked questions
What forms of L-aspartic acid can brands buy?
Common forms include crystalline, food grade, uSP grade and mineral aspartates. Ask each supplier for the specification sheet of the exact grade they quote.
What should the COA for L-aspartic acid include?
Expect identity, assay, related substances, loss on drying and residue on ignition and heavy metals and microbiology, each with its method, specification and result for that lot.
How should L-aspartic acid be stored?
Store L-aspartic acid in tightly closed, lined containers in a cool, dry place away from light and strong odors, and reseal opened packs promptly. Shelf life or retest date is set by the supplier's specification; assay, loss on drying and micro are the usual retest points for older stock.
What is the regulatory status of L-aspartic acid?
21 CFR 172.320 lists L-aspartic acid among the amino acids that may be safely used as nutrients added to foods. Under 21 CFR 172.320, added plus naturally present L-aspartic acid, including L-asparagine, may not exceed 7.0 percent by weight of the total protein of the finished food. FDA's Substances Added to Food inventory lists L-aspartic acid with the technical effects flavor enhancer, flavoring agent or adjuvant, and nutrient supplement. Health Canada's Workout Supplements monograph lists L-aspartic acid among its non-essential amino acids, with potassium aspartate and potassium magnesium aspartate as source ingredients and a dose range of 325 mg to 1 g per day.
More proteins and amino acids
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- Creatine Monohydratecreatine · micronized creatine
- L-TheanineTheanine · N-ethyl-L-glutamine
- Pea ProteinPisum sativum protein · pea protein isolate
- Whey Protein IsolateWPI · whey isolate
- Whey protein concentrateWPC · WPC 80
- Whey protein hydrolysateWPH · hydrolyzed whey protein
- Micellar caseinmicellar casein isolate · casein micelles
- Milk protein concentrateMPC · MPC 70
- Milk protein isolateMPI · milk protein
- Sodium caseinatecasein sodium · caseinate sodium salt
- Calcium caseinatecasein calcium · caseinate calcium salt
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