High Potency Vitamin C (formerly Buffered C Powder)
Scored by the Formulate Research Team · Last reviewed July 2026
Overview: Thorne High Potency Vitamin C (formerly Buffered C Powder)
Vitamin C with buffering minerals, so it’s gentle on the stomach High Potency Vitamin C supplies a higher amount of vitamin C per serving than our capsules, with calcium, magnesium, and potassium mineral-ascorbates that serve as a buffer to make it easier on the digestive system.
Score Breakdown
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Ingredients per Serving
| Ingredient | Amount |
|---|---|
| Vitamin CAscorbic Acid289 systematic reviews · 808 randomised trials | 2.35 g |
| CalciumAscorbate702 systematic reviews · 3290 randomised trials | 350 mg |
| MagnesiumAscorbate250 systematic reviews · 790 randomised trials | 350 mg |
| PotassiumAscorbate87 systematic reviews · 1010 randomised trials | 99 mg |
Certifications & Testing
Recommended Use
Mix 1 scoop with at least 8 ounces of water once daily.
Warnings
ALLERGY WARNING This product is contraindicated in an individual with a history of hypersensitivity to any of its ingredients. PREGNANCY If pregnant, consult your health-care practitioner before using this product. INTERACTIONS There are no known interactions or contraindications at publication date. OTHER WARNINGS Vitamin C can cause diarrhea in some individuals in large doses, which can vary fro
Frequently Asked Questions
What is Thorne High Potency Vitamin C (formerly Buffered C Powder)'s Formulate score?
Thorne High Potency Vitamin C (formerly Buffered C Powder) scores 81 out of 100 (grade A-) on Formulate's ingredient-level rubric, which weighs evidence quality, dose accuracy, bioavailability, transparency, safety, and manufacturing practices.
Is Thorne High Potency Vitamin C (formerly Buffered C Powder) worth it?
Thorne High Potency Vitamin C (formerly Buffered C Powder) scores 81/100 (grade A-). That puts it in Formulate's top tier: its ingredient doses, forms, and label transparency hold up against the clinical evidence, and it carries credible third-party testing. Formulate grades every product with the same automated rubric, so the score reflects the formula — not marketing or sponsorships.
What's in Thorne High Potency Vitamin C (formerly Buffered C Powder)?
Each serving contains Vitamin C (2.35 g), Calcium (350 mg), Magnesium (350 mg), Potassium (99 mg). Serving size: 1 Scoop. 42 servings per container.
How do I take high potency vitamin c (formerly buffered c powder)?
Mix 1 scoop with at least 8 ounces of water once daily.
Who makes High Potency Vitamin C (formerly Buffered C Powder)?
High Potency Vitamin C (formerly Buffered C Powder) is made by Thorne. See Formulate's full grade and product lineup for Thorne on its brand page.
Is Thorne High Potency Vitamin C (formerly Buffered C Powder) third-party tested?
Thorne lists the following certifications and testing for this product: NSF Certified, Gluten Free, Dairy Free, Soy Free, Thorne Verified, Natural Flavors, Natural Colors, GMP Certified.
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Disclosure. Formulate may earn a commission from purchases made through links on this page. Commissions never influence scores — every product is graded by the same automated rubric. This page is for educational purposes only and does not replace advice from a qualified healthcare provider.