L-Arginine 500mg 250 Capsules | Free-Form Pharmaceutical Grade, Now Foods

NOW Foods L-Arginine delivers 500 mg of free-form, pharmaceutical-grade (USP) L-arginine per capsule — the body's primary nitric oxide precursor — in a flexible 250-capsule format for cardiovascular, circulatory, and exercise performance support.

Why

L-arginine is a conditionally essential amino acid — the body can make it, but not always in sufficient quantities during intense exercise, illness, injury, or ageing. Its most critical role is as the primary substrate for nitric oxide (NO) synthesis: NO signals blood vessel walls to relax and widen, improving circulation, supporting healthy blood pressure, and enhancing oxygen and nutrient delivery to working muscles. What sets this product apart is the use of free-form USP pharmaceutical-grade L-arginine — the most bioavailable form, absorbed directly without conversion from a salt form like L-arginine HCl. The 500 mg per capsule format also allows precise dose adjustment from 500 mg to 3,000 mg daily depending on individual needs. Backed by NOW Foods' 50+ years of GMP-certified quality, this is a straightforward, high-integrity amino acid supplement.

Key Benefits

• Primary nitric oxide precursor — supports vasodilation and healthy blood flow
• Supports cardiovascular health and healthy blood pressure via NO-mediated vasodilation
• Enhances exercise performance — improved circulation supports oxygen and nutrient delivery to muscles
• Supports the urea cycle — essential for ammonia detoxification and healthy liver function
• Involved in DNA synthesis, protein production, tissue repair, and growth hormone secretion
• Flexible dosing — 500 mg per capsule allows precise adjustment from 500 mg to 3,000 mg daily
• Free-form USP pharmaceutical grade — maximum bioavailability and purity

Formula Highlights

• L-Arginine (Free-Form, USP, 500 mg per capsule) – pharmaceutical-grade, free-form amino acid for maximum absorption; the body's primary substrate for nitric oxide synthase
• Nitric Oxide Pathway – arginine → nitric oxide via nitric oxide synthase (NOS); NO relaxes vascular smooth muscle, widening blood vessels and improving circulation
• Urea Cycle Role – arginine is a key intermediate in the hepatic urea cycle, supporting conversion of toxic ammonia to urea for safe excretion
• Free-Form vs Salt Forms – free-form L-arginine is absorbed directly; salt forms (e.g. L-arginine HCl) require dissociation before absorption and may deliver less active arginine per gram

Supplement Facts

Serving Size: 2 Capsules | Servings Per Container: 125

* Daily Value not established.

Suggested Use

Take 2 capsules 1 to 3 times daily as needed. For best absorption, take between meals or at bedtime with a carbohydrate drink — insulin released in response to carbohydrates enhances amino acid uptake into cells. The 500 mg per capsule format allows flexible dose adjustment to suit individual needs.

Other Ingredients

Gelatin (capsule), magnesium stearate (vegetable source), silica. Contains no sugar, salt, starch, yeast, wheat, gluten, corn, soy, milk, egg, shellfish, or preservatives. Not vegan — contains bovine gelatin capsule.

About NOW Foods

Founded in 1968 and still family-owned, NOW Foods is one of the most trusted names in nutritional supplements worldwide. With over 1,400 products manufactured to GMP (Good Manufacturing Practice) standards, NOW is committed to making high-quality natural products accessible and affordable. Their use of USP pharmaceutical-grade ingredients reflects a genuine commitment to purity and potency that has made them a go-to brand for health professionals and informed consumers for more than 50 years.

Warnings

⚠️ Do not use this product if you have had a myocardial infarction (heart attack) or have established coronary artery disease — arginine supplementation is contraindicated in these conditions. Do not use if you have glaucoma unless specifically prescribed by a physician. Avoid if you have a history of herpes simplex — arginine can promote HSV replication. For adults only. Consult your healthcare practitioner before use if pregnant, breastfeeding, taking medication, or managing any medical condition. Keep out of reach of children. Store in a cool, dry place.