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Brand-quality audit Published Sep 30, 2025 Recalibrated Jun 14, 2026

Double Wood Supplements

Mid-tier single-ingredient supplement brand with strong COA access but imperfect regulatory and community trust signals.

Double Wood Supplements brand audit

Composite trust

75 /100 Adequate

Double Wood Supplements is a mid-tier, U.S.-based direct-to-consumer supplement brand whose strongest objective signal is testing transparency: sampled products provide public COA/test links, potency checks, heavy-metal panels, microbial panels, and some ISO/IEC 17025-accredited third-party reports.2456815 Formulation quality is uneven but generally respectable for a single-ingredient brand: some products match study-level dosing or use premium forms such as Magtein, while some trend-driven claims and botanicals are less well supported.10152430 The main trust caveats are no verified NSF/USP/Informed Sport certification, ConsumerLab’s mixed 4-approved/2-not-approved public report card, an older FDA warning letter for hangover/intoxication claims, and a recent Prop 65 lead-warning notice involving Maca Root.1617192425 Overall, this is a reasonable brand for shoppers who value accessible COAs and fair pricing, but not the best fit for athletes needing banned-substance certification or shoppers who want practitioner-grade certification and spotless regulatory history.212435

Quality

89 /100

Strong

Formulation

68 /100

Mixed

Transparency

89 /100

Strong

Safety

70 /100

Adequate

Value

72 /100

Adequate

Sentiment

64 /100

Mixed

Evidence summary

Evidence summary

Double Wood Supplements presents a transparent, third-party-tested brand posture, but public evidence here is limited to product-level documentation rather than a full company-wide audit.

  • Double Wood publishes batch-specific COAs for magnesium glycinate, indicating product-level third-party assay documentation 5.
  • A dedicated blog post frames third-party testing as a core brand promise and explains why it matters 3.
  • No material red flags surfaced, but public documentation does not verify manufacturing practices across the whole brand 2.

Top strengths

  • Unusually accessible product-level COAs and third-party test reports
  • Fair mid-tier pricing for a brand with visible testing documentation
  • Mostly single-ingredient formulas with disclosed amounts
  • Current BBB A+ accreditation and visible complaint responses

Key concerns

  • No verified NSF, USP, or Informed Sport certification found
  • ConsumerLab public report card is mixed: 4 of 6 approved, 2 not approved
  • Older FDA warning letter for Dycetin hangover/intoxication claims
  • Recent California Prop 65 notice alleging unwarned lead exposure for Maca Root

Badges

Public COAs Third-party tested Premium ingredients Fair value Responsive support Recent safety issue

Axis by axis

What the evidence shows

Quality

89/100 Strong

Manufacturing/testing quality is Double Wood’s strongest objective category. The brand has product-page COA/test links, sampled potency/identity results, heavy-metal panels, microbial panels, and ISO/IEC 17025-accredited assay evidence, but it lacks NSF/USP-style certification and ConsumerLab’s public report card shows a mixed 4-of-6 approved record.

Formulation

68/100 Mixed

Double Wood’s formulation profile is better than many budget brands because it leans single-ingredient, discloses amounts, and uses some premium forms. The main limitation is not hidden blends but evidence calibration: some products are well-dosed and research-aligned, while trend-driven categories such as GLP-1 support, fadogia/testosterone support, and older hangover positioning are less convincing.

Transparency

89/100 Strong

Transparency is above average for product testing and below perfect for ownership/supply-chain clarity. The public COA/test-link practice is a real strength, but current parent ownership and exact ingredient sourcing remain less clear than the lab-documentation story.

Safety

70/100 Adequate

Double Wood does not show the kind of recent federal recall or confirmed contamination event that would drive the safety score into the lowest tier, but its record is not clean. The main safety/regulatory hits are an older FDA warning letter for unapproved hangover/intoxication claims and a recent California Prop 65 lead-warning notice involving Maca Root.

Value

72/100 Adequate

Double Wood generally offers fair value: mid-tier pricing, frequent single-ingredient formats, and stronger-than-average test-document access. The value weak spots are capsule burden, some specialty-product cost per effective serving, and a small but real cluster of autoship/billing complaints.

Sentiment

64/100 Mixed

Social sentiment is mixed but not broadly hostile. BBB status is currently positive and the brand has loyal users, but Reddit/Trustpilot complaints and ConsumerLab’s mixed public test record keep sentiment below 'community favorite' territory.

The rubric

How every score was built

Each axis opens at a category baseline, then moves only on dated, cited evidence — never a gut call. That is the whole difference from a star rating: every one of these 35 adjustments is a receipt you can check.

Points What moved the score
Quality baseline 50 89 Strong
+16 Public product-page COAs and test links for sampled products: sampled magnesium glycinate, spermidine, fadogia, TUDCA, and magnesium L-threonate pages each exposed Certificate of Analysis and/or third-party test-report links. This is not a single batch-lookup portal, so I awarded the low/mid end of the public-COA range: +16 rather than +20. 2457810111315 Current website and 2024-2026 COA documents; full weight. · full weight
+11 Third-party independent testing disclosed and evidenced in sampled lab documents. The company claims all products are third-party tested; sampled PDFs include external assay reports and COAs prepared for Double Wood LLC. 23568911121415 Current site plus 2024-2026 documents; full weight. · full weight
+8 ISO/IEC 17025-accredited testing evidence. Multiple third-party assay PDFs list ISO/IEC 17025:2017 accreditation by PJLA, but this appears concentrated in a specific outside lab rather than a brand-owned accredited lab program, so I used the low end of the +8 to +12 range. 69121415 2024-2026 lab reports; full weight. · full weight
+5 Heavy-metal testing disclosed and shown in sampled COAs for arsenic, cadmium, lead, and mercury, with methods such as ICP/ICP-MS and limits/results shown on product COAs. 457810111315 2024-2026 COAs and current product pages; full weight. · full weight
+5 Microbiological testing disclosed and shown in sampled COAs, including total plate count, yeast/mold, coliform, E. coli, Salmonella, and Staphylococcus aureus on several sampled documents. 581115 2024-2026 COAs; full weight. · full weight
−6 Mixed independent quality report card: ConsumerLab’s public Double Wood page says 6 products were tested, 4 were Approved for quality, and 2 were Not Approved. Pattern calculation: 2/6 not approved = 33% of tested sample; because details are paywalled and the sample is limited, I applied a modest -6 rather than a severe quality-failure penalty. 16 Current public ConsumerLab brand page; full weight. · full weight
— Not scored No complete line-wide audit was possible. ConsumerLab’s product-specific pass/fail details are paywalled, so the -6 adjustment is based only on the public brand report card. I also did not verify every active SKU’s current lot-specific COA.
Formulation baseline 50 68 Mixed
+10 Effective dosing across sampled products: sampled products with reasonably evidence-aligned servings included L-theanine 200 mg, Magtein magnesium L-threonate 2 g/serving, TUDCA 500 mg/day, spermidine 10 mg/serving, and vitamin D3/K2 drops. Pattern calculation: about 5 of 8 reviewed products had dosing that clearly matched or plausibly tracked common study/market dosing, so I awarded the low end of the +10 to +15 majority-of-line range. 713152425 Current product pages and 2025 reviews; full weight. · full weight
+8 Bioavailability technology and premium forms in sampled products: Magtein magnesium L-threonate, magnesium bisglycinate/glycinate, synthetic non-animal TUDCA, and disclosed spermidine trihydrochloride provide stronger ingredient-form signals than generic commodity forms. Not line-wide enough for the high end. 471315 Current product pages and 2024-2026 COAs; full weight. · full weight
+5 Branded/premium ingredient signal: magnesium L-threonate product is labeled as Magtein, a patented clinically studied ingredient form. Because this signal is not demonstrated across most of the catalog, I awarded a partial +5 rather than +8. 1524 Current product page and 2025 review; full weight. · full weight
+6 Mostly single-ingredient, non-proprietary approach. Official and editorial sources describe Double Wood as emphasizing single ingredients and avoiding proprietary-blend style stacking, making ingredient amounts easier to evaluate. 12425 Current brand page and 2025 reviews; full weight. · full weight
+3 Minimal inactive ingredients in sampled COAs: examples include simple capsule/filler systems such as HPMC/hypromellose, rice flour, microcrystalline cellulose, and stearate. Awarded +3 because this is observed in sampled documents but not proven line-wide. 5811 2024-2026 COAs; full weight. · full weight
−8 Claims without strong evidence or overstated marketing in parts of the line. Healthline states some claims are overstated and some ingredients have limited evidence; FDA’s 2020 warning letter found hangover/intoxication claims for Dycetin created unapproved-drug issues; and a 2026 law-firm investigation alleges unsupported GLP-1 support/weight claims. Because the 2026 item is only an investigation and the FDA letter is older, I used a mid penalty, not the maximum. 172430 Mixed timing: 2026 investigation full weight, 2025 review full weight, 2020 FDA letter 50% historical context; blended penalty. · full weight
−6 Limited human-evidence concern for some niche botanicals/men’s-health products. Fadogia product marketing includes testosterone, athletic performance, libido, fertility, and immune claims, while broader editorial review notes limited evidence for some ingredients in the line. Pattern is emerging, not proven line-wide, so I applied a partial -6. 1024 Current product page and 2025 review; full weight. · full weight
— Not scored No comprehensive SKU-by-SKU clinical-dose audit was completed. Several product claims depend on ingredient-level literature that varies in quality, and I did not access paywalled ConsumerLab product-level details.
Transparency baseline 50 89 Strong
+21 Public COA/test accessibility on product pages. Unlike brands that only say 'tested,' sampled Double Wood pages link COAs and/or third-party reports directly from the product page. Because this is product-page access rather than a centralized batch lookup portal, I awarded +21 instead of the full +25 public-portal maximum. 45781011131415 Current website and 2024-2026 documents; full weight. · full weight
+10 Third-party testing disclosed with lab details. Double Wood says every supplement is third-party tested and sampled reports identify outside labs, methods, dates, lot numbers, and in several cases ISO/IEC 17025 accreditation. 2369121415 Current website and 2024-2026 reports; full weight. · full weight
+12 Test results published regularly/at point of sale. Product pages contain COA/test links and sometimes explanatory testing copy, but coverage was sampled rather than confirmed for every SKU, so I used +12 rather than the top +18. 4710131524 Current product pages; full weight. · full weight
+7 Basic ownership/entity and management disclosure. Official About page names CEO Eric Wenke and founders Reese and Evan Wood; BBB lists Double Wood LLC, addresses, entity type, alternate name, and management contacts. This is basic-to-good disclosure, not full parent-company disclosure. 12126 Current official/BBB/LinkedIn pages; full weight. · full weight
+6 Manufacturing and location disclosure. Product pages state manufactured in an FDA-registered cGMP facility in the USA from globally sourced materials, and BBB/LinkedIn list Pennsylvania business locations. Facility names and complete supply chain are not disclosed, so this stays at +6. 4713152126 Current pages; full weight. · full weight
−5 Ownership/parent-company ambiguity after private-equity transactions. Public deal sources report Boyne acquired a majority interest in 2021 and later sold Double Wood to Gryphon Investors in March 2026, while the official About page and BBB profile emphasize management/founders and do not clearly reconcile that parent-ownership chain. Small penalty because ownership is findable, but not clearly surfaced by the brand. 1212829 2026 transaction source is within 2 years; full weight. · full weight
−5 Emerging subscription/autoship transparency complaints. BBB shows recent billing complaints including disputed auto-refill/subscription issues, but the volume is limited relative to the business and BBB also shows company responses. Pattern calculation: 2 billing complaints among 7 BBB complaints in 3 years plus Trustpilot mentions = emerging, not systematic; applying about 25-30% of a -18 subscription-trap penalty. 2223 2024-2026 complaints; full weight. · full weight
−7 Marketing claims challenged by regulators/investigators. FDA’s 2020 warning letter cited unapproved-drug hangover/intoxication claims, and a 2026 law-firm investigation alleges unsupported GLP-1 support/weight-management marketing. Because one source is an old resolved regulatory letter and the other is only an investigation, I applied a moderate transparency penalty. 171830 2020 FDA item discounted as 5-10 years old; 2026 investigation full weight; blended. · full weight
— Not scored I did not verify every SKU for current lot-specific COA availability. I also could not confirm from an official Double Wood or Gryphon page whether the March 2026 PE transaction is fully closed and reflected in current ownership records.
Safety baseline 90 70 Adequate
−15 FDA warning letter for Dycetin hangover/intoxication claims. FDA issued a July 23, 2020 warning letter stating claims established the product as an unapproved new drug; FDA’s July 29, 2020 update included Double Wood LLC among companies warned over illegal hangover-product claims. Severity selected: -30 for unapproved-drug/disease-style claims; temporal discount: 5-10 years old = 50%; final -15. 1718 July 2020; 5-10 years old as of 2026-06-14; 50% temporal weight applied. · 50% weight
−5 California Proposition 65 60-day notice alleging unwarned lead exposure from Double Wood Supplements Maca Root. This is a notice/allegation, not a final judgment in the reviewed sources. Safety exception applies even though it appears product-specific; selected low -5 due to single product, Prop 65 context, and lack of adjudicated finding. 1920 Filed July 5, 2024; within 2 years of scoring date; full weight. · full weight
— Not scored I did not access FDA inspectional 483 records through FOIA or paid regulatory databases. I also did not find a final court outcome for the Prop 65 notice in the reviewed sources.
Value baseline 50 72 Adequate
+14 Fair-to-affordable price positioning for a third-party-tested brand. Healthline describes Double Wood as affordable and worth considering for shoppers who want supplements that do not break the bank; product-page examples show mid-tier pricing such as $19.95 magnesium glycinate and $30.95 Magtein magnesium L-threonate. Awarded +14 for fair/below-premium pricing with testing documentation. 4152425 Current product pages and 2025 reviews; full weight. · full weight
+10 Price justified by testing transparency. The brand is not the cheapest possible option, but public COAs, third-party testing, and ConsumerLab’s 4-of-6 approved public result support better-than-generic value. Awarded +10 rather than +15 because 2 of 6 ConsumerLab-tested products were not approved and NSF/USP certifications are absent. 2451624 Current pages and 2024-2026 tests; full weight. · full weight
+6 Free shipping and 30-day money-back guarantee. Medical News Today reports free U.S. shipping and a 30-day money-back guarantee on the first bottle/multipacks; these are modest value positives. 25 2025 review; full weight. · full weight
+3 Bulk/multi-pack discounts visible on sampled product pages. Awarded the low end because discount generosity varies and was not audited line-wide. 101315 Current product pages; full weight. · full weight
−6 Serving-size/value friction in some products. Magnesium L-threonate requires 4 capsules per 2 g serving and the MNT tester criticized serving size/cost; magnesium glycinate provides 60 mg elemental magnesium per capsule despite 400 mg magnesium glycinate front-end positioning. Pattern calculation: 2 of 8 sampled products with notable serving-size friction = 25%; applying about 50% of a -12 small-serving penalty = -6. 41525 Current pages and 2025 review; full weight. · full weight
−5 Subscription/autoship complaints can create perceived value loss. BBB and Trustpilot include recent complaints about auto-refill, delivery, refund, or subscription handling. Pattern is limited/emerging rather than systematic, so -5 rather than -12 to -18. 2223 2024-2026 complaints; full weight. · full weight
— Not scored No full market basket audit was completed. Pricing changes frequently, and I sampled representative products rather than every SKU and every competitor.
Sentiment baseline 60 64 Mixed
+8 Current BBB A+ rating and accreditation. BBB lists Double Wood as accredited since August 12, 2025 with an A+ rating. Awarded +8, the low end of the BBB-positive range, because accreditation is recent and complaint history still exists. 21 Current BBB profile; full weight. · full weight
+5 Documented responsiveness to complaints. BBB complaint pages show company responses to several complaints, and Trustpilot shows company replies to recent reviews. Awarded +5 because responses are visible but not uniformly praised by consumers. 2223 2024-2026 complaint/review responses; full weight. · full weight
+7 Positive customer/editorial sentiment around quality, price, and COA access. Healthline reports satisfied customers praise quality ingredients, affordable prices, and public COAs; product pages show strong internal review ratings for products such as Magtein, though own-site reviews are weighted cautiously. 152440 Current product page, 2025 review, 2025 Reddit thread; full weight. · full weight
−7 Mixed service/shipping/refund sentiment. Healthline calls reviews mixed; BBB shows 7 complaints in the last 3 years; Trustpilot includes recent delivery/refund/customer-service complaints. Pattern is mixed, not overwhelmingly negative, so -7 rather than -12 to -18. 222324 2024-2026 complaints and 2025 review; full weight. · full weight
−5 Community skepticism on Reddit/forums about testing depth, review incentives, and perceived effectiveness. Multiple threads raise concerns, but they are anecdotal, sometimes old, and counterbalanced by positive/defensive community comments; applying a modest -5. 37383940 Mixed: 2022-2025 threads; mainly 2-5 years old or recent; blended full/75% effect represented in modest penalty. · 75% weight
−4 ConsumerLab mixed public report card affects community trust. 4 of 6 products approved is a positive, but 2 Not Approved products create legitimate skepticism. Scored as -4 in social because shoppers see mixed external validation. 16 Current public ConsumerLab page; full weight. · full weight
— Not scored I did not scrape all Amazon reviews, TikTok/Instagram comments, or every Reddit thread. Social scoring is based on representative BBB, Trustpilot, editorial, ConsumerLab, and forum evidence.

Best for

  • Budget-conscious supplement stackers who want mostly single-ingredient products with visible COAs and third-party test documents rather than proprietary blends.[^1][^4][^24]
  • Nootropics/biohacker shoppers comparing niche ingredients such as Magtein, spermidine, TUDCA, and magnesium glycinate who are willing to verify lot-specific COAs before buying.[^7][^13][^15]
  • Shoppers who prioritize fair direct-to-consumer pricing and public test documentation over NSF/USP certification marks.[^2][^16][^24]

Skip if

  • You are a tested athlete, military user, or NCAA/USADA-regulated competitor who needs NSF Certified for Sport, Informed Sport, or BSCG-style banned-substance certification; I did not verify those certifications for Double Wood.[^24][^25][^35]
  • You want a brand with a spotless regulatory/legal record; Double Wood has a 2020 FDA warning letter and a 2024 Prop 65 notice in the reviewed record.[^17][^19][^20]
  • You are uncomfortable with autoship/subscription friction or mixed customer-service reports; recent BBB and Trustpilot records include billing, delivery, and support complaints.[^22][^23]

Questions

What shoppers ask about Double Wood Supplements

Is Double Wood Supplements a Chinese company?

No. The business records and profiles reviewed identify Double Wood LLC as a U.S./Pennsylvania company with Pennsylvania business addresses, and the brand says products are manufactured in the USA from globally sourced materials.1421 “Globally sourced” means some raw materials may come from outside the U.S.; it does not make the company Chinese.

What is the #1 most trustworthy vitamin company?

There is no single objective “#1” vitamin company for every shopper. If your definition of trustworthy is third-party certification, brands/products carrying USP Verified, NSF, or Informed Sport marks have stronger external verification than brands relying mainly on their own COA program; Double Wood has COAs and third-party testing but no verified USP/NSF/Informed Sport certification in the reviewed evidence.24343536

Who owns Double Wood Supplements?

The operating brand is Double Wood LLC; the official site names Eric Wenke as chief executive and Reese and Evan Wood as founders/strategic advisors, while BBB lists Eric Wenke as CEO/Owner.121 Transaction sources report Boyne Capital acquired a majority stake in 2021 and that Boyne sold Double Wood to Gryphon Investors in March 2026; I did not find an official Double Wood page clearly reconciling that current parent-ownership chain.2829

Are Double Wood Supplements FDA approved?

No. Dietary supplements are generally not FDA-approved before sale the way drugs are, and Double Wood’s site carries the standard supplement disclaimer that its statements have not been evaluated by FDA.333 FDA did issue a 2020 warning letter to Double Wood LLC over Dycetin hangover/intoxication claims, which is a post-market enforcement action, not an approval.1718

Is Double Wood Supplements a trustworthy brand?

Reasonably trustworthy for shoppers who value public COAs and fair pricing, but not top-tier verified. The positives are product-level COAs, third-party test reports, current BBB A+ accreditation, and some ConsumerLab approvals; the caveats are no NSF/USP/Informed Sport certification found, a mixed ConsumerLab 4-of-6 approved public record, an older FDA warning letter, and a recent Prop 65 notice.4516171921

What vitamin cuts dementia risk by 40%?

The headline refers to vitamin D: a 2023 observational study reported that vitamin D supplement exposure was associated with 40% fewer dementia diagnoses compared with no exposure.3132 That finding is association, not proof that vitamin D prevents dementia, so dosing decisions should be based on blood levels, diet, sun exposure, and clinician guidance rather than the headline alone.

Sources

  1. 1. Double Wood Supplements — About / Team / Story (2026)
  2. 2. Are Double Wood supplements third-party tested? (2026)
  3. 3. The Importance of Third-Party Tested Supplements — Double Wood blog (2025)
  4. 4. Double Wood Magnesium Glycinate product page (2026)
  5. 5. AILCI Double Wood Magnesium Glycinate Capsules COA, 2026 (2026)
  6. 6. Double Wood Magnesium Glycinate third-party assay report, 2025 (2025)
  7. 7. Double Wood Spermidine product page (2026)
  8. 8. AILAB Double Wood Spermidine Trihydrochloride COA, 2026 (2026)
  9. 9. Double Wood Spermidine third-party identification report, 2024 (2024)
  10. 10. Double Wood Fadogia Agrestis product page (2026)
  11. 11. Double Wood Fadogia Agrestis COA, 2024 (2024)
  12. 12. Double Wood Fadogia third-party identity report, 2026 (2026)
  13. 13. Double Wood TUDCA product page (2026)
  14. 14. Double Wood TUDCA third-party assay report, 2025 (2025)
  15. 15. Double Wood Magnesium L-Threonate / Magtein product page (2026)
  16. 16. ConsumerLab.com — Double Wood testing report card public page (2026)
  17. 17. FDA Warning Letter: Double Wood LLC, MARCS-CMS 593766 (2020)
  18. 18. FDA constituent update: warning letters to seven companies selling hangover products (2020)
  19. 19. California OAG Prop 65 60-Day Notice 2024-02785 (2024)
  20. 20. Prop 65 notice PDF: Double Wood Supplements Maca Root / lead (2024)
  21. 21. BBB Business Profile — Double Wood Supplements (2026)
  22. 22. BBB Complaints — Double Wood Supplements (2026)
  23. 23. Trustpilot reviews — doublewoodsupplements.com (2026)
  24. 24. Healthline: Double Wood Supplements Review — A Dietitian’s Take (2025)
  25. 25. Medical News Today: Double Wood Supplements Review (2025)
  26. 26. LinkedIn company profile — Double Wood Supplements (2026)
  27. 27. Inc. 5000 company profile — Double Wood (2025)
  28. 28. Dealroom: Boyne Capital sells Double Wood to Gryphon Investors (2026)
  29. 29. PrivSource: Boyne Capital acquires majority stake in Double Wood Supplements (2021)
  30. 30. Migliaccio & Rathod LLP: Double Wood GLP-1 Support Supplements Investigation (2026)
  31. 31. ScienceDaily / University of Exeter: Taking vitamin D could help prevent dementia (2023)
  32. 32. Alzheimer’s & Dementia: Vitamin D supplementation and incident dementia (2023)
  33. 33. FDA: Dietary Supplements — What You Need to Know (2026)
  34. 34. USP Verified Mark — dietary supplement verification (2026)
  35. 35. Informed Sport certified supplement brands (2026)
  36. 36. USP Dietary Supplement Verification Program (2026)
  37. 37. Reddit: Negative review of Double Wood Supplements (2024)
  38. 38. Reddit: Double Woods' third party tests are a sham? (2022)
  39. 39. Reddit: Doublewood Supplements is shady / third-party testing discussion (2024)
  40. 40. Reddit: Double Wood Supplements Review — Is it a good brand? (2025)

Recalibrated Jun 14, 2026 · 35 scored adjustments · 33 distinct citations across 40 sources

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