Checked against public sources on July 30, 2026 · LookCloser does not sell or recommend supplements.
Does the marketing hold up?
Ingredient amounts are hidden inside “C4 Sport® Performance Blend”. The panel lists “C4 Sport® Performance Blend” (3.181 g) as a combined amount. A blend total can’t tell you whether any single ingredient reaches a dose used in research.
“Couldn’t verify” means we looked and found no public proof — not a mark against the product. Most supplement claims cannot be independently verified by anyone, so grey is the normal state of this industry.
| Calories | 5 |
|---|---|
| Total Carbohydrate | 1 g |
| Total Sugars | 0 g |
| Includes 0g Added Sugars | 0 g |
| Vitamin B6 (as Pyridoxine HCl) | 3.4 mg |
| Vitamin B12 (as Cyanocobalamin) | 60 mcg |
| Calcium | 25 mg |
| Magnesium (as Magnesium Chloride) | 12 mg |
| Sodium (as Sodium Citrate) | 60 mg |
| Potassium (as Dipotassium Phosphate) | 20 mg |
| C4 Sport® Performance Blend | 3.181 g |
| C4 Sport® Energy Blend | 1.138 g |
Printed on the package: NSF · NSF CERTIFIED SPORT · NSF Certified for Sport
We read 12 lines from the package photograph. It is our transcript of the label, not the manufacturer’s panel, and it may be incomplete.
1 promise needs a closer look.
Published research exists for ingredients in this formula. Whether this product’s doses match those studies could not be confirmed.
Ingredient research can support context, but it is not a trial of this exact product.
We found no named, citable study of this product or formula. The claim may rest on ingredient research rather than a trial of this product.
Headlines first. Open evidence only when you want the source trail.
You are being sold on an ingredient the verified panel does not separately declare. The brand should explain the mismatch.
The listing presents 135 mg for caffeine, but vision:claude-cli:subscription does not contain a same-name quantified row. The saved image read may be incomplete, so this is a specific question to resolve rather than a contradiction.
Locked evidence record →Open the full source-linked findingThe barcode matches, so we are checking the right product rather than a look-alike.
Open Food Facts resolves 810390029198 to "C4 Sport Pre-Workout Blue Raspberry" (C4) — consistent with this listing.
Locked evidence record →Open the full source-linked findingThese are evidence gaps, not strikes against the product.
Filed address
332 Grace Lane, Austin, Texas 78746, UNITED STATES
USPTO identifies the public owner or applicant behind this brand wordmark. This does not by itself identify the product manufacturer or prove where the product was made. Open USPTO source ↗
We could not match an amount on this product to a studied range for the same ingredient, so these links are ingredient background rather than a measurement of this product.
Not a score. Studies disagree with each other and change over time, so this sits beside the evidence rather than counting toward it — it is here so you can read the sources yourself.
The panel lists 12 mg of magnesium per serving. Studies we found used 200 mg–420 mg a day, so this sits below that range.
Study ranges differ between trials and change as research changes. This is background reading, not a pass, a failure, or a recommendation.
$0.55 per labeled serving
matching UPC/GTIN · checked Jul 30, 2026
View on Amazon ↗We only show a price when the seller publishes the same barcode as the bottle. We haven’t found that match here.
Search iHerb ↗We only show a price when the seller publishes the same barcode as the bottle. We haven’t found that match here.
Search Target ↗We only show a price when the seller publishes the same barcode as the bottle. We haven’t found that match here.
Search Walmart ↗Only one exact price was available at build time; prices change by date, seller, and promotion.
No official brand storefront is confirmed in this record. That is neutral, but it prevents a direct brand-price, label, review, and document check.
Reference prices only · no affiliate links · every compared seller must publish the matching UPC/GTIN.
The summary stops at product-specific facts. The full report preserves every source, calculation, limitation, and unresolved check for review or sharing.
Record built August 02, 2026. Sources: source listing observed at check time · USPTO Trademark Search · Keepa exact-listing history · NIH / published research · certification and regulator records where available. LookCloser publishes evidence and gaps; it does not advise for or against any supplement. Evidence-based corrections welcome.