Nutrex L-Arginine 1000, 120 Caps

Six-dimension breakdown

Why this scored 63/100

Nutrex L-Arginine 1000 delivers a single ingredient (L-arginine hydrochloride typically) at a stated single dose (1000 mg per capsule) — transparent single-ingredient labeling that contrasts favorably with the proprietary-blend Nutrex T-booster SKU also in this batch. L-arginine is a semi-essential amino acid, a substrate for nitric oxide synthesis, and one of the most-studied performance/cardiovascular ingredients. Its evidence base is moderate: real effects on peripheral vasodilation (mild blood-pressure lowering at higher doses), some evidence for endothelial function support, and limited but real evidence for exercise performance at cumulative doses above 6g/day. A single 1000 mg capsule per serving is a modest dose; the studied effects generally require 3-6+ grams cumulative (3-6 capsules of this product per day). L-citrulline is arguably a more efficient nitric oxide precursor than L-arginine at equivalent doses because L-arginine has significant first-pass liver metabolism and L-citrulline converts to L-arginine after absorption — but L-arginine is a defensible legacy choice. Nutrex is a real US-based sports supplement brand with cGMP manufacturing. Scored Standard tier reflecting the single-ingredient transparency and moderate evidence base.

Evidence & sources

The Vyvata score's Evidence dimension measures the quality of published RCT support for a product's active ingredients at the label dose. Our source hierarchy: double-blind RCTs in MEDLINE-indexed journals > single-blind RCTs > open-label trials > observational studies > mechanism papers > N=1 case studies (anecdotes). Predatory journals and manufacturer-authored studies without independent replication are weighted down.

Product-specific evidence citations for this item are embedded in the analysis text on the "Analysis" tab. For the full framework and evidence hierarchy, see the methodology page.

How to read the Evidence dimension

• 80–100: Multiple double-blind RCTs in indexed journals directly testing this product OR the exact ingredients at the exact dose.
• 60–79: Single double-blind RCT + supporting ingredient literature at the studied dose.
• 40–59: Open-label trials + ingredient literature; no product-specific double-blind evidence.
• 20–39: Ingredient literature only; no product-specific trials or trials in predatory venues.
• 0–19: No credible evidence base or unverifiable claims.

FAQ data has not been generated for this product yet. See the site FAQ for general questions.

Customer reviews

All the data we have on this product

Every VSF-related metafield surfaced verbatim. Nothing hidden. If you spot data that looks wrong, let us know.

VSF score

63 / 100

Tier

Standard

Category

Supplements

Subcategory

cardiovascular heart

Last scored

August 24, 2026

Third-party certifications

None on record at time of scoring

Vendor

PoorBoySupplements.com

Product type

Testosterone Boosters

Tags

PoorBoySupplements.com, Shopify Collective

Every score is set from the published rubric, audit-logged, and rescored whenever new evidence emerges (published trials, updated labels, third-party testing releases). Every vendor is scored on the same criteria — no pay-to-play. See our editorial-independence disclosure for the full policy, including brands with an editorial relationship to this site.