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Product analysis · Life Extension

Life Extension Buffered C — non-daily serving

Buffered blend · Powder

Why this score?
Testing & evidence
3/25
Ingredient/formulation quality
8/20
Value
10/20
Dose context & clarity
4/15
Manufacturer transparency
9/10
Label/ingredient transparency
4/10
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Testing transparency: 3/25
PowderFormat
4,000 mgDaily dose
454 gPack size
—Price/day
No current offer in USCompare alternatives

We may earn a commission from qualifying purchases. This never affects our scores.

The score, explained

Our scoring methodology
Testing & evidence12.8/100
3 points contributed · weighting 25
Ingredient/formulation quality40/100
8 points contributed · weighting 20
Value50/100
10 points contributed · weighting 20
Dose context & clarity25/100
4 points contributed · weighting 15
Manufacturer transparency85/100
9 points contributed · weighting 10
Label/ingredient transparency40/100
4 points contributed · weighting 10

The score compares product data, not medical effectiveness or individual suitability. Prime and affiliate commission contribute no points.

Testing & evidence

Testing claimed

Evidence status
Testing claimed
Manufacturer statement
Amazon listing says: "HIGH QUALITY: Life Extension's vitamin C powder is tested for quality and purity in independent laboratories." Life Extension's own FAQ says its ingredients and final products are "verified using advanced analytical methods like high performance liquid chromatography and mass spectrometry" and that the company is "GMP registered with NSF International." I did not find an independently verifiable product-specific COA, lab report, or registry entry for this exact Buffered Vitamin C Powder.
Laboratory
Not recorded
Certification body
Not recorded
Batch
Not recorded
Batch-specific report
Not established in this record
Report date
Not recorded
Evidence checked
2026-09-14 09:30:38

Dose & value

Vitamin C form
Buffered blendPowder
Daily dose
4,000 mgAbove adult upper limit
Serving size
Serving or nutrient confirmation pending
Pack size
454 g
Servings per day
1
Price per day
—
Price last checked
Not disclosed

Daily cost uses the recorded label serving; a larger dose earns no value advantage. The label serving is not a recommendation for your personal intake.

Vitamin C formulation details

Comparison form
Buffered blend
Chemical form as disclosed
Ascorbic acid with calcium, magnesium and potassium carbonates; zinc gluconate
Vitamin C / serving (mg)
4000
Vitamin C / day (mg)
4000
Pack size as labelled
454 g
Recommended serving / frequency
1 rounded teaspoon (5.4g) providing 4,000mg vitamin C, mixed into water; label does not state an explicit daily frequency beyond "start low, take with meals"
Comparison basis for a serving range
Not disclosed
Tablets, capsules, gummies, grams or ml / serving
5.4
Time-release claim (yes / no / unknown)
no
Liposomal claim (yes / no / unknown)
no
Bioflavonoids included / amount
Not listed
Rose hips included / amount
Not listed
Acerola included / amount
Not listed
Zinc included / amount
Yes · 2 mg per 5.4 g
Other active ingredients
Calcium 145 mg, magnesium 55 mg, zinc 2 mg, potassium 365 mg per 5.4 g
Sugars / sweeteners
None listed
Allergen statement
No separate allergen statement captured; check current pack
Vegan / vegetarian label status
Vegan claim on listing

Product sources & research notes

Listing and manufacturer details describe the label; they do not independently verify product claims. Check the current pack before use.

Ingredients & suitability

Vegan Vegetarian

Excipients
L-ascorbic acid, calcium carbonate, magnesium carbonate, zinc gluconate, potassium carbonate
Allergens
No separate allergen statement captured; check current pack
Carrier / source
Not disclosed — check the current label
Other active ingredients
Calcium 145 mg, magnesium 55 mg, zinc 2 mg, potassium 365 mg per 5.4 g

Manufacturer transparency

Brand
Life Extension
Legal company
Quality Supplements and Vitamins, Inc. (d/b/a Life Extension)
Manufacturing model
Not conclusively disclosed (mixed in-house/third-party)
Manufacturing location
United States (New Jersey facility referenced)

View the full brand profile →

What the record makes clear

  • Active amount is disclosed.
  • The current record does not support a daily cost calculation.

What to keep in mind

  • Verify the current label and the batch covered by any testing report.
  • A product score cannot determine whether you need a supplement.

Explore the alternatives

Compare alternative

Solgar Vitamin C 1000 mg, 250 Vegetable Capsules

Why this score?
Testing & evidence
21/25
Ingredient/formulation quality
12/20
Value
11/20
Dose context & clarity
14/15
Manufacturer transparency
6/10
Label/ingredient transparency
7/10
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Testing evidence
Evidence status
Recognised certification
Manufacturer statement
NSF Certified for Sport registry entry for Solgar Vitamin C 1000 mg (listing detail page id=1415634)
Laboratory
Not recorded
Certification body
NSF Certified for Sport®
Batch
Not recorded
Batch-specific report
Not established in this record
Report date
Not recorded
Evidence checked
2026-09-14 07:29:22
$0.12per day
$31.19per pack
View AnalysisBuy Nowon Amazon
Compare alternative

THORNE Vitamin C 1,000 mg, Ascorbic Acid Supplement, 60 Capsules

Why this score?
Testing & evidence
21/25
Ingredient/formulation quality
13/20
Value
5/20
Dose context & clarity
14/15
Manufacturer transparency
9/10
Label/ingredient transparency
7/10
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Testing evidence
Evidence status
Recognised certification
Manufacturer statement
Thorne product page says: "This product has been third-party tested and certified to verify what's in the package matches what's on the label and to confirm it contains no unsafe levels of contaminants, such as heavy metals, pesticides, and microorganisms." NSF registry independently lists "Thorne® Vitamin C 1,000 mg" as a finished product under NSF/ANSI Standard 173.
Laboratory
Not recorded
Certification body
NSF International
Batch
Not recorded
Batch-specific report
Not established in this record
Report date
Not recorded
Evidence checked
2026-09-14 07:29:53
$0.32per day
$19.00per pack
View AnalysisBuy Nowon Amazon
Compare alternative

Nature Made Chewable Vitamin C 1000 mg per Serving, 90 Tablets, Orange Flavor, 45 Day Supply

Why this score?
Testing & evidence
21/25
Ingredient/formulation quality
12/20
Value
7/20
Dose context & clarity
14/15
Manufacturer transparency
6/10
Label/ingredient transparency
6/10
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Testing evidence
Evidence status
Recognised certification
Manufacturer statement
Nature Made product page states: "USP Verified and from #1 pharmacist recommended vitamin and supplement brand.*" and "USP has tested and verified ingredients, potency and manufacturing process." USP’s own verification program page explains that USP is an independent third-party organization and that through comprehensive auditing, reviewing, and testing it verifies dietary supplements.
Laboratory
Not recorded
Certification body
USP
Batch
Not recorded
Batch-specific report
Not established in this record
Report date
Not recorded
Evidence checked
2026-09-14 07:23:19
$0.26per day
$11.89per pack
View AnalysisBuy Nowon Amazon