Thorne Vitamin C with Flavonoids
vs
Klean Athlete Klean Collagen+C Unflavored
Supplement Comparison

  • Vitamin C: Thorne Vitamin C with Flavonoids has 10× more
  • The image below shows:
    • Side-by-side charts with label nutrient amounts, per serving
    • Nutrient forms as listed on the label
    • 6 nutrients compared
Bar chart: per-serving label amounts and listed forms for Thorne Vitamin C with Flavonoids vs Klean Athlete Klean Collagen+C Unflavored.

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Frequently asked questions

Which active ingredients does Thorne Vitamin C with Flavonoids have?

  • Vitamin C appears as Ascorbic Acid
  • Citrus Bioflavonoids

Which active ingredients does Klean Athlete Klean Collagen+C Unflavored have?

  • Vitamin C appears as Mixed ascorbates from organic amla (Phyllanthus emblica)
  • Collagen Peptides appears as Hydrolyzed Collagen (from bovine)
  • Protein

Which categories do Thorne Vitamin C with Flavonoids and Klean Athlete Klean Collagen+C Unflavored belong to?

  • Antioxidant Complex
  • Collagen

What health concerns do Thorne Vitamin C with Flavonoids and Klean Athlete Klean Collagen+C Unflavored address?

  • Antioxidant Support
  • Immune System Support
  • Liver & Detox Support
  • Recovery & Repair
  • Skin, Hair & Nail Health
  • Athletic Performance
  • Healthy Aging & Longevity
  • Joint & Bone Health

Which product has a higher amount of Vitamin C per serving?

  • Thorne Vitamin C with Flavonoids has the highest total amount of Vitamin C: 500 mg per serving

How do the serving sizes compare between the two supplements?

  • Serving size:
    • Thorne Vitamin C with Flavonoids: 1 capsule
    • Klean Athlete Klean Collagen+C Unflavored: 1 scoop
  • Vitamin C
    • This supplement has 500 mg
    • Recommended Dietary Allowance in men: 90 mg
    • Recommended Dietary Allowance in women: 75 mg
    • Tolerable Upper Intake Level: 2000 mg
  • Vitamin C
    • This supplement has 50 mg
    • Recommended Dietary Allowance in men: 90 mg
    • Recommended Dietary Allowance in women: 75 mg
    • Tolerable Upper Intake Level: 2000 mg

Last updated: February 9, 2026

  • Sources & Methodology: Nutrient data and forms are taken directly from Supplement Facts labels. Reviewed and standardized by the VIOscan Research Team. Learn more on the Methodology page.
  • We show the Recommended Dietary Allowance (RDA) when available. If no RDA exists, we show the Adequate Intake (AI). Tolerable Upper Intake Levels (UL) are used for upper limits. Unless otherwise noted, RDAs shown correspond to healthy adults aged 19–50 years and are sex-specific. Separate values exist for 51–70 years and >70 years, and pregnancy and lactation are excluded. All values come from the Dietary Reference Intakes (DRIs) published by the National Academies of Sciences, Engineering, and Medicine (NASEM), Food and Nutrition Board (FNB).
  • Transparency: We’re funded by our users. We don’t have sponsors or affiliate links, and we don’t sell supplements.
  • Editorial standards: we provide independent, impartial and objective data analysis.
  • This analysis is for educational purposes only. It is not a substitute for medical advice.
  • Questions? Read our Frequently Asked Questions or contact us, we’re here to help.
  • See an error? Report it through our Contact page.
  • Author: VIOscan Research Team