NOW Sports, L-Leucine Powder supplement bottle
NOW

Sports, L-Leucine Powder Review

What We Researched
1 active ingredient analyzed · 1 inactive ingredient decoded · 9 brand certifications checked · Last updated: Aug 2026
100
Product Score Excellent
100
Brand Score Excellent

Two independent scores — the product and the brand behind it, never blended into one number. See our methodology.

Product Analysis

Transparency Excellent

Supplement Facts

IngredientAmount% DV
L-Leucine Powder (Instantized, Non-GMO) (5,000 mg) 5 g *
Bioavailability Excellent

Absorption Rating

  • L-Leucine Powder (Instantized, Non-GMO) (5,000 mg) Good
Other Ingredients Excellent

Fillers & Additives

  • Non-GMO sunflower lecithin (<5%)
Efficacy Excellent

Dosage Analysis

  • L-Leucine Powder (Instantized, Non-GMO) (5,000 mg) 5 g Effective

Supplement Facts

Ingredient Amount % Daily Value
L-Leucine Powder (Instantized, Non-GMO) (5,000 mg) 5 g *

Other Ingredients

Inactive ingredients used in manufacturing. All rated for safety.

Non-GMO sunflower lecithin (<5%) Unknown
Brand Trust Report
NOW

Founded 1968 · Bloomingdale, Illinois, USA · 1759 products · nowfoods.com

Certifications

9 certifications
Informed Sport Verified Source
Npa Gmp Verified Source
Consumerlab Verified Source
Labdoor Verified Source
Fda Gmp Inspections Verified Source
Non Gmo Project Verified Source
Usda Organic Verified Source
Vegan Certified Verified Source
Informed Choice Verified

Transparency

5 claims
Coa Availability — Verified Source
Third Party Testing Claim — Verified Source
Testing Lab Disclosure — Claimed
In House Testing — Verified Source

Violation History

8 incidents
Lawsuit Mislabeled St. John's Wort supplement, containing significantly less of the active ingredient than advertised.NoneSource
Lawsuit A data breach that compromised personal and health information of employees and dependents.2023Source
Prop 65 Lead2021-11-30Source
Recall NOW Real Food® Raw Macadamia Nuts2020-06-12Source
Recall NOW Real Food® Raw Macadamia Nuts2020-06-12Source
Recall NOW Real Food® Zesty Sprouting Mix2018-06-21Source
Lawsuit Misleadingly using slack-fill packaging for their Vitamin C supplements.2015Source
Fda Warning Adulterated Dietary Supplement due to pesticide (quintozene) contamination in American Ginseng.2007-10-12Source
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Frequently Asked Questions
Is NOW Sports, L-Leucine Powder a good supplement?

NOW Sports, L-Leucine Powder received a product quality score of 100/100 in GoodSupp's independent analysis, placing it in the top tier of supplements we've analyzed. The product contains 1 active ingredients with 51 servings per container. Of the 1 inactive ingredients, 0 are rated safe and 0 are flagged for review. The manufacturer, NOW, holds a brand trust score of 100/100 with 9 verified certifications including Informed Sport, Npa Gmp, Consumerlab, Labdoor.

What are the ingredients in NOW Sports, L-Leucine Powder?

NOW Sports, L-Leucine Powder contains 1 active ingredients: L-Leucine Powder (Instantized, Non-GMO) (5,000 mg) (5 g). Each ingredient's dosage, form, and safety rating is analyzed independently in GoodSupp's full product breakdown.

Is NOW Sports, L-Leucine Powder safe to take?

NOW Sports, L-Leucine Powder has been analyzed for ingredient safety across all its components. Always consult your healthcare provider before starting any new supplement, especially if you take medications or have underlying health conditions.

Is NOW a trustworthy supplement brand?

NOW receives a brand trust score of 100/100 based on GoodSupp's independent analysis of certifications, regulatory history, and transparency practices. Founded in 1968 and headquartered in Bloomingdale, Illinois, USA, the company offers 1759 products in their lineup. They hold 9 verified certifications including Informed Sport, Npa Gmp, Consumerlab, Labdoor. Third-party certifications are independently verified and indicate the brand meets specific quality, purity, and manufacturing standards. Note: NOW has 8 historical regulatory incidents on record, which are factored into the trust score.

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Disclaimer: GoodSupp provides independent supplement quality analysis for informational purposes only. Scores are generated algorithmically based on ingredient profiles, brand certifications, and public records — read our methodology. This is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Product data is sourced from manufacturer labels and public databases. GoodSupp is not affiliated with any supplement brand.