NOW L-Citrulline 750 mg: Pure Nitric Oxide Booster & Muscle Recovery Support

NOW L-Citrulline 750 mg Veg Capsules (SKU 0083) provide a pure, free-form amino acid designed to optimize blood flow, vascular elasticity, and exercise endurance. While traditionally recognized for its vital role in the body’s urea cycle, L-Citrulline is now widely regarded in clinical nutrition as the single most dependable nutritional precursor for stimulating systemic nitric oxide (NO) production.

Unlike basic arginine products that are largely broken down during digestion, pure L-Citrulline is absorbed intact. It enters the bloodstream smoothly, allowing your body to sustain circulation, support healthy blood pressure within normal ranges, and flush exercise-induced metabolic waste.

• ✓ Potent 750 mg Pure Free-Form Dose: Delivers flexible, non-acidic dosing without fillers or bonded malate diluents.
• ✓ Proven Nitric Oxide Catalyst: Converts to systemic L-arginine more efficiently than oral L-arginine itself.
• ✓ Natural Ammonia Clearance: Accelerates the urea cycle to clear muscular waste and minimize delayed-onset muscle fatigue.
• ✓ Clean Vegetarian Formula: Packaged in plant-based hypromellose capsules, verified non-GMO, Halal, Kosher, and allergen-screened.

How Citrulline Works: The Science of Blood Flow and Ammonia Buffering

To appreciate why athletes and wellness enthusiasts choose L-Citrulline, it helps to understand what researchers call the “L-Arginine Paradox.” When you ingest supplemental L-arginine directly, up to 70% of it is degraded within the gut and liver by the digestive enzyme arginase before reaching wider circulation. In contrast, oral L-Citrulline bypasses intestinal breakdown and liver first-pass metabolism completely.

In a landmark human clinical trial published in the British Journal of Clinical Pharmacology, researchers demonstrated that oral L-citrulline supplementation raised plasma L-arginine concentrations and stimulated nitric oxide-dependent signaling far more effectively and sustainably than equivalent or larger doses of L-arginine (Schwedhelm et al., 2008, PMID: 17953710). Once absorbed, your kidneys convert L-citrulline back into L-arginine, which feeds the endothelial nitric oxide synthase (eNOS) enzyme. This biological pathway expands arterial blood vessels (vasodilation), improving oxygen delivery and nutrient distribution directly to hard-working muscles and cardiovascular tissues (Bailey et al., 2015, Journal of Applied Physiology, PMID: 26023227).

Beyond supporting blood flow, L-Citrulline plays an essential role as an intermediate in the liver's urea cycle. When muscle tissue contracts repeatedly during strenuous exercise, it generates toxic ammonia and cellular waste. High ammonia concentrations disrupt cellular energy and trigger muscular fatigue. L-Citrulline binds with carbamoyl phosphate to clear excess ammonia, converting it into harmless urea that the body safely excretes (Allerton et al., 2018, Nutrients, PMID: 30029482). Clinical studies have noted that this detoxification support helps reduce post-exercise muscle soreness and speeds recovery (Pérez-Guisado & Jakeman, 2010, Journal of Strength and Conditioning Research, PMID: 20386132).

Pure L-Citrulline vs. Citrulline Malate: Many pre-workout formulas use “citrulline malate,” which combines citrulline with malic acid in a 2:1 or 1:1 ratio. This means a significant portion of what you consume is malic acid, not active citrulline. NOW L-Citrulline 750 mg delivers 100% pure free-form amino acid per capsule, giving you complete dosing control without added stomach acidity.

Supplement Facts & Complete Ingredients

Every batch of NOW L-Citrulline 750 mg (NOW Product # 0083 / UPC 733739000835) is produced under strict Current Good Manufacturing Practices (cGMP). The full formulation and label panel are detailed below:

† Daily Value (DV) not established. Note: Each individual vegetarian capsule contains 750 mg of pure L-Citrulline.

Other Ingredients: Hypromellose (cellulose capsule), Stearic Acid (vegetable source), and Silicon Dioxide.

Allergen Free From: Not manufactured with wheat, gluten, soy, milk, egg, fish, shellfish, tree nut, or sesame ingredients. Produced in an audited GMP facility that processes other ingredients containing these allergens. Suitable for vegetarians and vegans. Certified Kosher (Triangle K) and Halal.

NOW In-House Lab Testing & Strict Contaminant Standards

Many supplement brands rely entirely on third-party broker certificates without verifying what is actually in the bottle. NOW Foods operates one of the most advanced analytical testing infrastructures in the natural products industry, conducting more than 16,000 analytical tests and assays every single month across 68 distinct analytical categories.

NOW’s on-site analytical and microbiological laboratories maintain rigorous ISO/IEC 17025:2017 accreditation awarded by the American Association for Laboratory Accreditation (A2LA). This accreditation ensures that testing protocols, calibration, and technician competencies conform to international pharmaceutical and scientific testing benchmarks.

• ✓ ICP-MS Heavy Metal Screening: Inductively Coupled Plasma Mass Spectrometry instruments analyze incoming raw ingredients and finished capsules down to parts-per-billion (ppb) detection limits. Every batch must meet stringent specifications for lead, inorganic arsenic, cadmium, and mercury, comfortably conforming to California Proposition 65, USP, and European Union environmental limits.
• ✓ HPLC Potency & Amino Identity: High-Performance Liquid Chromatography (HPLC) verifies that each capsule contains genuine free-form L-Citrulline at full label strength, ruling out inferior fillers or synthetic adulteration.
• ✓ Microbiological Purity: Culture and rapid automated assays screen for the complete absence of human pathogens including Salmonella spp., Escherichia coli, and Staphylococcus aureus, while verifying total aerobic, yeast, and mold counts fall within strict hygienic thresholds.
• ✓ cGMP Facility Certification: Manufactured under Current Good Manufacturing Practices certified by Intertek, ensuring consistent sanitation, lot control, and uncompromised packaging integrity.

Recommended Usage, Athletic Dosing & Safety Precautions

Standard Daily Use: As a dietary supplement, take 1 to 2 capsules 1 to 2 times daily between meals with 8 to 12 ounces of water.

Athletic Workout Protocol: For individuals seeking enhanced vasodilation, muscle pumps, and intra-workout endurance, clinical research suggests consuming 2 to 4 capsules (1,500 mg to 3,000 mg of pure L-Citrulline) approximately 45 to 60 minutes prior to physical training on an empty stomach.

Important Medical Considerations & Precautions

• Adults Only: Formulated specifically for adult use. Keep out of reach of children.
• Blood Pressure Medications: Because L-Citrulline increases nitric oxide and promotes vascular dilation, it may have an additive blood-pressure-lowering effect if taken alongside prescription antihypertensives (such as ACE inhibitors, beta-blockers, or calcium channel blockers). Consult your prescribing doctor before starting.
• Nitrates & PDE-5 Inhibitors: Do not use this supplement without medical clearance if you take prescription nitrate medications for heart conditions (such as nitroglycerin) or PDE-5 inhibitors (such as sildenafil or tadalafil), as severe hypotension may occur.
• Pregnancy & Nursing: If you are pregnant or breastfeeding, consult your healthcare provider before use, as safety data during pregnancy has not been established.
• Kidney or Liver Disease: While L-Citrulline supports normal ammonia processing and is converted in the renal system, individuals with chronic renal impairment or liver failure should use amino acid supplements only under clinical supervision.

Storage Advice: Store in a cool, dry place after opening. Do not eat the enclosed moisture-absorbing freshness packet. Natural color variation may occur in this product and does not affect quality or potency.

Why Buy NOW Citrulline From VitaNet®?

Where you purchase your supplements matters just as much as the brand you select. When you buy from anonymous third-party online marketplace sellers, you run the risk of receiving expired stock, heat-damaged capsules, or counterfeit merchandise stored in unmonitored conditions. VitaNet® provides direct, risk-free access to authentic, freshly manufactured supplements.

• ✓ Serving Customers Online Since 1995: Founded over 31 years ago, VitaNet® is an independent, family-owned American retailer with decades of hands-on expertise in human nutrition and dietary supplements[cite: 1].
• ✓ Unconditional 100% Money-Back Guarantee: We offer a risk-free 100% money-back guarantee on all products, and we even pay the return shipping costs—even on opened items[cite: 1].
• ✓ Verified Brick-and-Mortar Storefront: We operate an established physical storefront in Hartville, Ohio, and hold a stellar BBB A+ accredited business rating[cite: 1].
• ✓ Climate-Controlled Direct Inventory: All NOW Foods products are shipped directly from authorized manufacturer channels and stored in our temperature-regulated warehouse, safeguarding amino acid potency[cite: 1].
• ✓ Deep Selection & Value: We curate over 16,000 name-brand vitamins, herbs, and sports nutrition products at everyday competitive discount pricing[cite: 1].

Frequently Asked Questions (FAQ)

What is the primary difference between L-Citrulline and Citrulline Malate?

L-Citrulline is the pure, free-form amino acid, meaning every milligram on the label delivers active citrulline. Citrulline malate is chemically bonded with malic acid (typically in a 2:1 or 1:1 ratio), meaning you receive only 50% to 67% active citrulline by weight. NOW L-Citrulline 750 mg provides 100% unadulterated free-form citrulline in convenient vegetarian capsules without the stomach acidity often caused by bulk malic acid powder.

Why is L-Citrulline more effective than taking L-Arginine for nitric oxide?

When you swallow L-arginine supplements, the majority is destroyed in the intestines and liver by the enzyme arginase before entering general circulation. L-Citrulline bypasses intestinal arginase and liver metabolism entirely. It travels directly to the kidneys, where it converts smoothly into sustained circulating arginine, leading to higher, longer-lasting blood levels of nitric oxide than supplemental arginine can produce.

When is the best time to take NOW L-Citrulline 750 mg?

For general cardiovascular health and daily amino acid balance, take 1 to 2 capsules once or twice daily between meals with water. For pre-workout vasodilation, enhanced pumps, and reduced fatigue, take 2 to 4 capsules (1,500 mg to 3,000 mg) approximately 45 to 60 minutes before your exercise session.

Can I take NOW L-Citrulline if I am taking blood pressure medications?

Because L-Citrulline promotes blood vessel relaxation and supports healthy circulation, it may cause an additive hypotensive (blood-pressure-lowering) effect when combined with prescription antihypertensive drugs or nitrates. You should always speak with your physician or pharmacist prior to use if you take prescription cardiovascular medications.

How does L-Citrulline help reduce post-workout muscle soreness?

Intense weightlifting and cardiovascular exercise generate metabolic ammonia, which leads to muscular burn, fatigue, and delayed soreness. L-Citrulline plays an essential role in the liver’s urea cycle, converting toxic ammonia into urea for excretion through the urine. By clearing this cellular waste faster, citrulline helps active muscle tissue recover more rapidly.

How does NOW test for heavy metals and purity in this supplement?

NOW Foods tests every batch in their in-house, ISO/IEC 17025:2017 accredited laboratories using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to detect trace heavy metals (lead, arsenic, cadmium, and mercury) at parts-per-billion levels. They also use High-Performance Liquid Chromatography (HPLC) to confirm 100% active L-Citrulline identity and strict microbiological screening to ensure zero pathogen contamination.