“in GMP CERTIFIED”
Evidence →“GMP-certified” describes factory processes, not what is in the bottle. The claim does not name a certifier or public register that a shopper can check.
Exact product checked · barcode not publishedDouble Wood Supplements · checked Aug 2, 2026 · on sale since Jul 12, 2022🇺🇸 USPTO wordmark owner · Double Wood LLC · PENNSYLVANIA, USA
Quick read · Double Wood Supplements
Magnesium Glycinate 400mg for Relaxation
Checked against public sources on August 2, 2026 · LookCloser does not sell or recommend supplements.
90capsules
90servings per container
Does the marketing hold up?
Testing claimed — documentation not found. The observed listing claims third-party testing without naming a lab or certifier. No product-bound report is saved, so the claim cannot be verified as stated. …
Is the dose real?✓Listing and panel agreeboth say 60 mg of Magnesium
What a serving costsNo price found for this exact barcode
Is it tested?NSF seal printed on the labelwe read it off the package photo; not confirmed in NSF’s registry
Who’s behind it?🇺🇸Double Wood LLClimited liability company · PENNSYLVANIA, USA
Is it the real thing?No barcode publishedso it can’t be matched against certification, recall or other retailer records
Trouble on record?✓No recalls found
“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.
1◖ partly confirmed2? couldn’t verifyno contradictions · no recalls
The label itself
What the Supplement Facts panel says
| Magnesium (as magnesium glycinate) | 60 mg |
|---|---|
| Magnesium Glycinate | 400 mg |
Printed on the package: GMP · NSF · CONTENTS CERTIFIED · Third-Party Tested · Manufactured in the USA · NSF Contents Certified
We read 2 lines from the package photograph. It is our transcript of the label, not the manufacturer’s panel, and it may be incomplete.
Marketing claims, checked
The checks, one by one
The public sources did not settle the marketing promises on this label.
◐Partly confirmed1
Ingredient research can support context, but it is not a trial of this exact product.
?Couldn’t verify independently2
“Tested”
Evidence →No named laboratory or lot-specific certificate was found for this exact product. A related brand page names no testing issuer and links no product-bound report; its UPC is not published. NSF, IFOS, USP, and Informed-Sport were not checked in this record. This is a public-evidence limit, not a finding that testing did not occur.
“in the USA From Globally Sourced”
Evidence →“Made in USA” can describe only final bottling. Ingredient-sourcing records were not located for this product.
We looked and found no public proof. That does not count against the product.
Quick read · 2 useful findings
What is worth knowing.
Headlines first. Open evidence only when you want the source trail.
CheckedIs the label honest?
Listing claim matches the Supplement Facts panel
The label promise and the Supplement Facts amount agree.
Evidence and sources
The listing claims 60 mg; the photo-read Supplement Facts panel shows Magnesium (as magnesium glycinate) at 60 mg per serving — the listing text and its photo-read panel agree; this is internal consistency, not independent testing.
Locked evidence record →Open the full source-linked findingCheckedIs the label honest?
Every ingredient shows its amount · 2 ingredients listed.
Every ingredient shows its real amount — nothing is hidden in a proprietary blend.
Evidence and sources
The panel gives a per-ingredient amount rather than hiding quantities inside a proprietary blend, so each one can be compared to published research.
Locked evidence record →Open the full source-linked findingWhat remains open 1
- No FDA recall matched this brand in the current search.
These are evidence gaps, not strikes against the product.
Who owns the brand wordmark?
🇺🇸
Double Wood LLCLimited Liability Company · exact supplement-class mark for DOUBLE WOOD SUPPLEMENTS
Filed address
22 Lindsey Ave, Danville, PENNSYLVANIA 17821, 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 ↗
Research behind the findings
Dose and research context
The label amount is shown beside the range used in the linked ingredient studies.
Dose vs research
Magnesium
STUDIED RANGE0525 mg
60 mg per serving — below the 200–420 mg/day used in the linked studies.
Linked ingredient research · label amount, not a recommendation
Background reading
What the research says about these amounts
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 60 mg of magnesium per serving. Studies we found used 200 mg–420 mg a day, so this sits below that range.
0studied 200 mg–420 mg
Study ranges differ between trials and change as research changes. This is background reading, not a pass, a failure, or a recommendation.
Buying options
Where you can check or buy it
Open related seller leads before buying, then confirm the flavor, count, and serving size. Their prices are visible, but LookCloser does not claim savings until the pages share a UPC/GTIN.
Amazon
Submitted listing$10.95
Lowest New observed via Keepa on 2026-08-02.
View on Amazon ↗Brand website
Official product-page candidate · UPC absent$24.95
Useful official shopping lead; excluded from exact price comparisons.
Magnesium Glycinate Extra Strength · One Bottle. The page matches 90 capsules, but omits the identifier needed to bind the exact sellable unit.
Check brand website ↗iHerb
Not confirmedNo price confirmed
No matching product page was confirmed in the current record. Search results cannot be attached as this product until the UPC/GTIN matches.
Search iHerb ↗Target
Not confirmedNo price confirmed
No matching product page was confirmed in the current record. Search results cannot be attached as this product until the UPC/GTIN matches.
Search Target ↗Walmart
Not confirmedNo price confirmed
No matching product page was confirmed in the current record. Search results cannot be attached as this product until the UPC/GTIN matches.
Search Walmart ↗Related brand page publishes 3.0/5 across 1 reviews
The related page's review pool may differ from the observed listing. Because the page does not publish a matching UPC/GTIN, LookCloser does not attribute that review aggregate to this exact sellable unit.
Prices and stock are point-in-time observations. Related pages are never used as product evidence. No affiliate links; LookCloser earns nothing from these sellers.
Want to inspect the evidence?
The full report shows every source, the exact unresolved question, and the documentation that would settle it.
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.