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Douglas Laboratories C/Lysine Plus supplement bottle
Douglas Laboratories

C/Lysine Plus Review

What We Researched
2 active ingredients analyzed · 5 inactive ingredients decoded · 6 brand certifications checked · Page generated: Sep 2026
93
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
Vitamin C (as Ascorbic Acid) 2000 mg 2222%
L-Lysine Hydrochloride 1000 mg †
Bioavailability Very Good

Absorption Rating

  • Vitamin C (as Ascorbic Acid) Fair
  • L-Lysine Hydrochloride Good
Other Ingredients Excellent

Fillers & Additives

  • Hydroxypropyl Methylcellulose
  • Hydroxypropyl Cellulose
  • Ascorbyl Palmitate
  • Citrus Bioflavonoids
  • Microcrystalline Cellulose
Efficacy Excellent

Dosage Analysis

  • Vitamin C (as Ascorbic Acid) 2000 mg Effective
  • L-Lysine Hydrochloride 1000 mg Effective

Supplement Facts

Ingredient Amount % Daily Value
Vitamin C (as Ascorbic Acid) 2000 mg 2222%
L-Lysine Hydrochloride 1000 mg †

Other Ingredients

Inactive ingredients used in manufacturing. All rated for safety.

Hydroxypropyl Methylcellulose Safe

It is used as a coating for tablets and capsules.

Hydroxypropyl Cellulose Safe

Binds tablet ingredients and can form tablet coatings.

Ascorbyl Palmitate Safe

Prevents oxidation and extends shelf life of oil-based supplements.

Citrus Bioflavonoids Generally_safe

They are included for their antioxidant properties and potential health benefits.

Microcrystalline Cellulose Safe

Adds bulk to small-dose supplements to make tablets/capsules a manageable size.

Brand Trust Report
Douglas Laboratories

Founded 1955 · Pittsburgh, Pennsylvania, United States · 32 products · douglaslabs.com

Certifications

6 certifications
Consumerlab Source available Primary evidence
Fda Gmp Inspections Source available Primary evidence
Nsf Certified For Sport Source available Primary evidence
Nsf Gmp Source available Primary evidence
Usda Organic Source available Primary evidence
NSF Certified Supporting evidence unavailable

Transparency

5 claims
Third Party Testing Claim — Verified Evidence available Evidence
Coa Availability — Verified Evidence available Evidence
In House Testing — Verified Evidence available Evidence
Testing Lab Disclosure — True Brand claim; evidence unavailable

Violation History

2 incidents
Recall Douglas Labs Stress-B-Plus2024-10-07 Source available Primary source
Prop 65 Lead2008-10-22 Source available Primary source
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Frequently Asked Questions
Is Douglas Laboratories C/Lysine Plus a good supplement?

Douglas Laboratories C/Lysine Plus received a product quality score of 93/100 in GoodSupp's independent analysis, placing it in the top tier of supplements we've analyzed. The product contains 2 active ingredients with 30 servings per container. All 5 inactive ingredients (fillers, binders, capsule materials) are rated safe — a clean formulation with no flagged additives. The manufacturer, Douglas Laboratories, holds a brand trust score of 100/100.

What are the ingredients in Douglas Laboratories C/Lysine Plus?

Douglas Laboratories C/Lysine Plus contains 2 active ingredients: Vitamin C (as Ascorbic Acid) (2000 mg), L-Lysine Hydrochloride (1000 mg). Notable high-dose ingredients include Vitamin C at 2222% DV. Each ingredient's dosage, form, and safety rating is analyzed independently in GoodSupp's full product breakdown.

Is Douglas Laboratories C/Lysine Plus safe to take?

GoodSupp reviewed the inactive-ingredient data available for Douglas Laboratories C/Lysine Plus. All 5 inactive ingredients — including capsule materials, fillers, and binders — are currently classified as safe in GoodSupp's ingredient reference data. This label analysis cannot determine whether the product is safe for a particular person, and source labels may change. Always consult your healthcare provider before starting any new supplement, especially if you take medications or have underlying health conditions.

Is Douglas Laboratories a trustworthy supplement brand?

Douglas Laboratories receives a brand trust score of 100/100 based on GoodSupp's independent analysis of certifications, regulatory history, and transparency practices. Founded in 1955 and headquartered in Pittsburgh, Pennsylvania, United States, the company offers 32 products in their lineup. Note: Douglas Laboratories has 2 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.