L-Citrulline Powder for Endurance, Nitric Oxide and Recovery Formulas

L-Citrulline is used primarily for endurance, nitric oxide support and recovery. It is converted to L-arginine in the body via the citrulline-arginine cycle, replenishing the substrate for nitric oxide production, which supports blood flow and oxygen delivery during exercise. It is a standard ingredient in endurance, pre-workout, pump, cardiovascular and recovery products. Purecium supplies L-citrulline in two formats — Base and DL-Malate 2:1 — as 99% minimum USP/EP-grade powders for distributors, contract manufacturers, private-label producers and supplement brands.

L-Citrulline Base (CAS 372-75-8) is the free amino acid and delivers the highest citrulline content per gram, making it efficient for capsules and tablets. L-Citrulline DL-Malate 2:1 (CAS 54940-97-5) is a complex of two citrulline molecules with one DL-malic acid molecule; the malic acid participates in the Krebs cycle and supports energy production, which is why the 2:1 complex is the classic format in endurance and pre-workout blends. Both are 99% minimum assay; the choice is a formulation and positioning decision, and Purecium can supply either.

L-Citrulline is converted to L-arginine by argininosuccinate synthase and argininosuccinate lyase, mainly in the kidneys and vascular endothelium, in what is called the citrulline-arginine cycle. The regenerated arginine becomes the substrate for endothelial nitric oxide synthase, which produces nitric oxide to relax blood vessels and support blood flow. Because citrulline bypasses first-pass hepatic metabolism and recycles arginine, it is often described as providing more sustained nitric oxide support than arginine alone. The NIH Office of Dietary Supplements documents arginine and citrulline metabolism in its health information.

A high-purity L-citrulline should be assayed at 99.0% minimum on a dried basis by HPLC against the USP-NF or EP monograph, with identification by infrared spectroscopy and HPLC retention time, specific optical rotation confirming the L-enantiomer, loss on drying not more than 0.5%, residue on ignition within limits, heavy metals within monograph limits, conforming residual solvents and microbial counts within USP/EP limits. For the DL-Malate format, malic acid content confirms the 2:1 complex ratio. Purecium reports all of these on the batch Certificate of Analysis, including the assay method, production date and expiry date.

The two amino acids support the same pathway at different points. L-Arginine is the direct substrate of nitric oxide synthase but is substantially metabolized in the liver before reaching the circulation. L-Citrulline escapes hepatic metabolism and is converted to arginine in the kidneys and vascular tissue, so it is often described as raising circulating arginine levels more efficiently and for longer. Many sports-nutrition formulas therefore use citrulline or the DL-Malate form as the primary nitric oxide ingredient. The choice depends on product positioning; Purecium supplies both as B2B raw materials.

Yes. L-Citrulline has a long history of safe use as a food ingredient and is recognized by the FDA as GRAS. Sports nutrition products commonly provide 3 to 8 g of citrulline per serving, and studies have used single doses up to 15 g without serious adverse effects in healthy adults, with mild gastrointestinal discomfort the most commonly reported side effect at very high doses. The European Food Safety Authority has evaluated citrulline and related amino acids and considers them safe for use in food supplements within established limits. As with any ingredient, formulators should confirm destination-market practice for dosage and claim wording.

DL-Malic acid is a dicarboxylic acid that participates in the Krebs (citric acid) cycle as an intermediate in energy production. In the L-Citrulline DL-Malate 2:1 complex, malic acid is bound to citrulline so the two act together: citrulline supports the nitric oxide pathway while malate supports cellular energy metabolism during exercise. The 2:1 ratio (two citrulline to one malate) is the industry-standard stoichiometry for this ingredient. The complex is a single crystallized salt rather than a physical blend, giving consistent composition batch to batch.

Yes. L-Citrulline pairs well with L-arginine for complementary nitric oxide support (citrulline recycles arginine), with agmatine sulfate for vasodilation, and with beta-alanine for intramuscular buffering and endurance. These combinations are standard in pre-workout and pump formulas. Formulators should verify ingredient compatibility, particle-size matching and blend uniformity, and confirm label claims comply with destination-market regulations.

L-Citrulline is stable in dry powder blends, tablets and capsules under normal storage conditions, with a shelf life generally of 36 months from manufacture when stored in sealed containers below 25 degrees Celsius, protected from moisture. It has a mildly acidic taste in the DL-Malate form, which is easily masked in flavored powders. The crystalline powders are free-flowing and blend well; reseal containers immediately after use to avoid moisture pickup.

A professional supplier should provide a current specification sheet, a batch-specific Certificate of Analysis showing identification, HPLC assay, specific optical rotation, malate content where applicable, loss on drying, residue on ignition, heavy metals, residual solvents and microbial results, an SDS, allergen and gluten statements, and non-GMO declarations. Depending on your destination market, also request Kosher and Halal certificates, copies of the ISO 9001 and FSSC 22000 certificates, and stability data for registration purposes. Purecium provides this full documentation set on request for every shipment.

The minimum order quantity is 25 kg per format. The powder is packed in 25 kg drums with food-grade aluminum-foil inner bags, and samples and technical documentation are available before you commit. Standard production lead time is typically 7 to 15 working days after order confirmation, depending on the format and production schedule, with faster dispatch for stocked items. For North American customers, Purecium holds inventory at its US warehouse, enabling pickup or delivery within approximately two days. Export documentation is prepared for every shipment.

Enantiomeric purity is verified primarily by specific optical rotation measured against the pharmacopeial monograph value for L-citrulline, and confirmed by chiral HPLC methods when required. The monograph value for L-citrulline in USP-NF and EP is approximately +25 degrees, measured at 20 degrees Celsius in dilute hydrochloric acid, which distinguishes the L-enantiomer from the D-form and racemic mixtures. Fermentation production inherently yields the L-enantiomer. Buyers should always request the specific rotation result on the CoA and confirm the method.

L-Citrulline is recognized as GRAS by the FDA in the United States for use in food, and it is permitted as a food supplement ingredient in the European Union, where EFSA has assessed the safety of amino acids including citrulline. It is also listed in the USP-NF and European Pharmacopoeia monographs, which form the basis of its quality specification. Other markets apply their own rules, and permitted dosage levels and claim wording differ between jurisdictions. B2B buyers should verify per-market requirements before finalizing label strength. Purecium provides regulatory-support documents to assist with submissions.

Store L-citrulline in tightly sealed original containers in a cool, dry place below 25 degrees Celsius, protected from moisture. The crystalline powders are stable under these conditions, and shelf life is generally 36 months from the date of manufacture. The DL-Malate form is slightly hygroscopic, so reseal containers immediately after use and avoid humidity during blending. Each shipment's CoA states the production date and expiry date for inventory planning.

Purecium supplies L-Citrulline as a B2B raw material in two formats — Base and DL-Malate 2:1 — standardized to 99.0% minimum assay and produced to USP, EP and FCC standards via non-GMO fermentation. Every batch is HPLC-assayed and ships with a full Certificate of Analysis, SDS and supporting documentation, including specific optical rotation confirming L-enantiomeric purity. The minimum order is 25 kg, inventory is staged at our US warehouse for two-day pickup, and global delivery covers Hong Kong, mainland China, the EU and beyond. For long-term supply relationships, Purecium provides consistent quality, batch traceability, regulatory documents and direct technical communication rather than one-off spot pricing.