NOW Foods Arginine and Citrulline Powder (12 oz / 340 g)
Whether you are looking to push harder during resistance training, improve muscle recovery after exertion, or support healthy everyday blood flow, Arginine and Citrulline Powder delivers the body's two premier nitric oxide building blocks in one unflavored, pure free-form blend. Formulated by NOW Foods with an exact 1:1 ratio of L-Arginine (1,500 mg) and L-Citrulline (1,500 mg) per teaspoon, this clean amino acid powder bypasses digestive bottlenecks to sustain circulation longer than single-amino acid supplements can alone.
Quick Product Highlights:
✓1:1 Synergistic Ratio: 1.5 grams of Free-Form L-Arginine plus 1.5 grams of Free-Form L-Citrulline per serving.
✓Exceptional Value: Approximately 113 full servings per 12-ounce container.
✓Zero Additives: Free from artificial sweeteners, colors, silicon dioxide, and chemical flow agents.
✓VitaNet Guarantee: Backed by over 31 years of family-owned retail experience with a 100% money-back guarantee[cite: 1].
The Science in Plain English: Why Combine Arginine and Citrulline?
To understand why this dual powder works so well, it helps to understand what scientists call the "Arginine Paradox." L-Arginine is the direct ingredient your blood vessels use to manufacture nitric oxide (NO), a natural signaling gas that signals blood vessel walls to relax, widen, and allow oxygen-rich blood to surge through your tissues.
However, taking plain L-Arginine by itself has a major flaw: your digestive tract and liver contain an enzyme called arginase. When you swallow regular arginine, up to half of it is chewed up in the gut and liver before it ever reaches your bloodstream (known as first-pass metabolism).
The Citrulline Bypass Advantage
L-Citrulline completely slips past liver enzymes unharmed. Once inside your body, your kidneys and vascular lining convert L-Citrulline right back into fresh, sustained L-Arginine inside your micro-vessels.
The result: L-Arginine provides an immediate, rapid spike in blood circulation, while L-Citrulline works like a steady time-release reservoir. In a 2019 double-blind randomized clinical crossover trial published in the European Journal of Applied Physiology (Suzuki et al.), co-ingestion of oral L-arginine and L-citrulline synergistically elevated blood plasma arginine and nitric oxide metabolites (NOx) significantly higher and faster than taking either amino acid alone, directly boosting cycling power output and reducing perceived physical exertion.
Key Everyday Health & Fitness Benefits
1. Fuller Muscle Pumps and Aerobic Endurance
By widening the arterial pathways supplying working muscles (vasodilation), this powder delivers more oxygen, glucose, and essential amino acids directly into muscle cells while training. Athletes experience fuller, longer-lasting muscular pumps without the heart palpitations, jitters, or sleep disruptions caused by high-caffeine pre-workout drinks.
2. Natural Ammonia Clearance & Faster Recovery
When you lift heavy weights or run long distances, your muscles break down proteins and generate metabolic ammonia ($NH_3$). Ammonia build-up creates that familiar muscle burn, brain fog, and heavy-legged exhaustion. Arginine and Citrulline serve as central engines of your body's urea cycle, turning toxic ammonia into harmless urea that is safely flushed out through your kidneys. Clearing this metabolic waste leaves your muscles feeling fresher the next day.
3. Cardiovascular Elasticity & Normal Blood Flow
As we age, natural endothelial production of nitric oxide naturally declines, making arteries stiffer and more resistant to blood flow. Regular intake of dietary arginine and citrulline supports normal endothelial elasticity and helps active adults maintain healthy vascular tone already within the normal range.
Complete Supplement Facts & Pure Ingredient Listing
NOW Foods manufactures this product with zero hidden excipients, fillers, or blending aids. Every single gram inside the container is pure, active, free-form amino acid powder.
Supplement Facts
Serving Size: 1 Level Teaspoon (approx. 3 g)
Servings Per Container: about 113
Amount Per Serving
% Daily Value
L-Arginine (Free-Form)
1.5 g (1,500 mg)*
L-Citrulline (Free-Form)
1.5 g (1,500 mg)*
* Daily Value not established.
Other Ingredients: None.
Allergen Statement: Not manufactured with wheat, gluten, soy, corn, milk, egg, fish, shellfish, tree nut, or sesame ingredients. Produced in a GMP-certified facility that processes other ingredients containing these allergens.
Dietary Suitability: Non-GMO, Vegan, Vegetarian, Kosher, Halal, Keto-Friendly, and Free of Corn, Dairy, and Soy.
NOW Brand Lab Testing & Strict Contaminant Constraints
In an unregulated supplement landscape where independent tests often discover under-dosed active ingredients or heavy metal contamination, NOW Foods stands as an industry benchmark for analytical rigor. Every production lot of NOW Arginine and Citrulline Powder undergoes rigorous screening before entering distribution.
State-of-the-Art Analytical Infrastructure:
Over 31,000 Monthly Lab Tests: NOW conducts tens of thousands of quality, identity, and purity analyses every single month across dedicated chemical and microbiological testing facilities.
ISO/IEC 17025:2017 Accredited Laboratories: The highest international operational standard for calibration, precision, and technical competence in analytical testing.
ICP-MS Heavy Metal Detection: Utilizing Inductively Coupled Plasma Mass Spectrometry (ICP-MS), NOW screens raw ingredients and finished goods down to trace parts per billion (ppb) for Lead, Arsenic, Cadmium, and Mercury, enforcing safety thresholds that are significantly more restrictive than standard USP limits.
Purity & Potency Verification: High-Performance Liquid Chromatography (HPLC) and Fourier-Transform Infrared Spectroscopy (FTIR) verify that each gram meets 100% of the active L-form amino acid claim with zero synthetic adulteration.
Comprehensive Microbial & Contaminant Screens: Advanced PCR and culture assays ensure batches test negative for pathogenic E. coli, Salmonella, Staphylococcus aureus, yeast, and mold, while screening for hundreds of common pesticide residues.
By maintaining full control in its internal laboratories rather than relying solely on paper certificates from foreign suppliers, NOW guarantees that what is printed on the label is exactly what dissolves in your glass.
How to Take It, Timing, and Practical Flavor Tips
Recommended Daily Use: Mix 1 level teaspoon (approximately 3 grams) twice daily as needed into 8 ounces of water, fruit juice, or your preferred beverage.
Empty Stomach Rule: For maximum absorption, take this powder at least 30 to 45 minutes before meals or workouts. Taking amino acids alongside heavy whole-food proteins (like chicken, eggs, or whey shakes) causes competing amino acids to overwhelm your intestinal transporters, blunting nitric oxide uptake.
Optimal Pre-Workout Window: Consume your first serving 30 to 45 minutes before exercise to allow citrulline conversion and peak vascular vasodilation to coincide with your working sets.
Honest Real-World Flavor Advice
Pure, unflavored free-form L-Arginine has an alkaline, naturally bitter taste that some first-time users find surprising because there are no masking sugars or artificial flavors added.
The Best Way to Mix It: Stir your teaspoon into 8 oz of tart cherry juice, freshly squeezed lemon or lime water, or an unsweetened citrus electrolyte drink. The natural citric acid instantly neutralizes the alkaline pH of the amino acids, eliminating the bitter aftertaste completely while supporting hydration.
Who Should Take It & Essential Safety Guidelines
While amino acids are natural building blocks found in food, concentrated nitric oxide supplements have strong physiological effects on blood vessels. Responsible usage is critical.
Best Suited For:
Weightlifters and athletes seeking stimulant-free pumps and improved endurance.
Runners, cyclists, and swimmers aiming to accelerate post-workout ammonia clearance and recovery.
Adults seeking natural nutritional support for vascular elasticity and circulation.
Precautions & Drug Interactions:
Blood Pressure & Heart Medications: Because arginine and citrulline promote vasodilation, consult your physician before use if you take antihypertensives, prescription nitrates (like nitroglycerin), or PDE-5 inhibitors, as blood pressure may drop too low.
Herpes Simplex Virus (Cold Sores): The herpes simplex virus requires arginine to replicate. Individuals prone to active cold sores or outbreaks should monitor their tolerance or balance their regimen with L-Lysine.
Kidney or Liver Impairment: Those with compromised renal or hepatic function should consult their nephrologist or physician before supplementing with high-dose urea cycle amino acids.
Adults Only: Keep out of reach of children. Consult a healthcare provider if pregnant or nursing. Do not ingest the moisture-absorbing freshness packet enclosed in the bottle.
Why Buy NOW Arginine & Citrulline Powder from VitaNet, LLC?
When ordering nutritional supplements online, sourcing directly from a verifiable, knowledgeable retailer matters. VitaNet, LLC is an independent, family-owned discount retailer providing premium vitamins and sports nutrition online since 1995[cite: 1].
Over 31 Years of Industry Experience: We have served health-conscious families with personal integrity and hands-on nutritional expertise since 1995[cite: 1].
100% Risk-Free Money-Back Guarantee: We offer a 100% money-back guarantee on all products[cite: 1]. If you are not completely satisfied, we will even pay the return shipping cost on opened or unopened items[cite: 1].
A+ Rating with the Better Business Bureau: Our business integrity and customer commitment are reflected in our BBB A+ accreditation[cite: 1].
Authentic, Direct Manufacturer Stock: We bypass unauthorized third-party marketplace sellers to provide factory-fresh, properly climate-controlled products directly from brands like NOW Foods[cite: 1].
Real Telephone Support: Speak with a real team member at our Hartville, Ohio location at (330) 877-8786 or toll-free at 1-800-877-8702 during business hours[cite: 1].
Frequently Asked Questions (FAQ)
What does Arginine and Citrulline Powder do?
This powder supplies your body with the primary building blocks needed to produce nitric oxide, a natural molecule that relaxes blood vessels to improve blood flow, nutrient delivery, and exercise stamina. It also powers the urea cycle to help your body clear exercise-induced ammonia for faster muscle recovery.
Why is this powder better than taking L-Arginine capsules alone?
When taken alone, up to 50% of oral L-arginine is broken down in the liver and intestines before entering systemic circulation. L-Citrulline bypasses liver metabolism and converts directly back into L-Arginine inside your blood vessels. Combining both in an equal 1:1 ratio elevates nitric oxide faster and keeps circulation elevated longer than arginine pills alone.
When is the best time to take NOW Arginine and Citrulline Powder?
For best results, take 1 level teaspoon twice daily on an empty stomach. If you are exercising, drink one dose 30 to 45 minutes prior to your workout to maximize muscular pumps and circulation, and take your second dose in the morning or between meals.
What does pure Arginine and Citrulline powder taste like?
Because this formula contains zero sweeteners or artificial flavorings, it has a naturally alkaline, slightly tart or bitter taste. We recommend mixing it into 8 ounces of lemon water, tart cherry juice, or orange juice to neutralize the taste completely.
How does NOW Foods test this powder for contaminants and heavy metals?
NOW Foods operates ISO/IEC 17025-accredited analytical laboratories performing more than 31,000 monthly tests. Every batch is analyzed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) for heavy metals (Lead, Arsenic, Cadmium, Mercury) down to parts per billion, HPLC for amino acid potency, and comprehensive screens for microbes and pesticides.
What is VitaNet's return policy on this product?
VitaNet, LLC offers a 100% money-back guarantee on all products[cite: 1]. If you are unsatisfied for any reason, we will refund your purchase price and cover the cost of return shipping, even on opened containers[cite: 1].
