Brand investigation Published Sep 30, 2025

Double Wood Supplements

The Paradox: A transparency-forward supplement brand with uneven third-party verification and compliance signals

Overall grade

61 /100 Mixed

Investigation confirms Double Wood posts Certificates of Analysis for products—and in at least some cases includes ISO 17025–accredited third-party potency tests—but independent industry testing has flagged underlabeling on certain items and the brand was named in a 2025 Proposition 65 lead notice, creating a split picture of quality control and transparency. ³⁴¹⁴².

Transparency

75 /100

Adequate

Scandal-Free

55 /100

Poor

Innovation

42 /100

Poor

Satisfaction

60 /100

Mixed

Value

72 /100

Adequate

The investigation

We analyzed regulatory records (FDA, Proposition 65), the company's posted COAs and third-party reports, pricing and product pages, investor/ownership disclosures, and complaint patterns (BBB, Trustpilot, Reddit). Where claims were unstable or contested, we prioritized primary documents (FDA letters, lab PDFs) and identified whether testing was finished-product or 'by input' component testing.

Key findings

What our investigation surfaced

01

Double Wood publishes Certificates of Analysis and, for some SKUs, links to ISO/IEC 17025–accredited third-party potency tests (e.g., Fisetin: Colmaric Analyticals). This is above the industry norm for public access, though coverage appears inconsistent across the catalog. ³⁴⁵⁶.
02

Some manufacturer COAs show 'result is substantiated through component testing'—a 'by input' approach that verifies formula inputs rather than finished-product identity/potency, which is less protective for consumers. ³.
03

Independent industry testing has reported significant shortfalls for specific Double Wood items: NOW Foods' PS testing found 16%–45% of label claim on a Double Wood Phosphatidylserine lot purchased on Amazon; NaturPro's 'bad supplements' list flags Double Wood magnesium glycinate front-panel labeling (400 mg compound vs. 60 mg elemental) and shows ~69–71 mg elemental per cap (fits 60 mg claim but can mislead shoppers). ¹⁴¹⁵.
04

Regulatory risk signals exist: a 2020 FDA Warning Letter for drug claims (Dycetin) and a 2025 Proposition 65 Notice alleging lead exposures without warning for several botanicals. ¹².
05

Customer sentiment is mixed: BBB shows both strong praise and sharp complaints, including subscription/returns friction; Trustpilot reflects similar variance with some alleging poor quality and others praising service. ¹²¹¹¹³.

Most surprising finding

An outside lab program reported a Double Wood phosphatidylserine lot at just 16% of labeled potency—illustrating why lot-matched third-party PDFs matter. ¹⁴.

Company profile

Who they actually are

Ownership

Founded by brothers Reese and Evan Wood (2013). In Jan 2021, Boyne Capital acquired a majority stake in Double Wood LLC, with leadership including CEO Eric Wenke. ⁹¹⁰.

Founded

2013 in Pennsylvania; grew via Amazon and direct-to-consumer. ⁹.

Headquarters

3510 Scotts Ln, Suite 219, Philadelphia, PA 19129; additional address used on lab docs: 205 Elmwood Ave, Sharon Hill, PA. ⁹⁶¹¹.

Market position

Mid-priced DTC brand emphasizing single-ingredient products, published COAs, and 'value' positioning; offers branded ingredients like Magtein and AstaReal. ⁷¹⁶.

Regulatory record

FDA Warning Letter (July 23, 2020) for disease-treatment claims related to 'Dycetin' (website promotion established the product as an unapproved drug). No FDA recall specific to Double Wood found. In Feb 2025, Environmental Research Center (ERC) issued a California Prop 65 Notice of Violation alleging lead exposure without warning for four botanicals (Astragalus, Marshmallow Root, Psyllium Husk, Bee Pollen). Case timeline ongoing. ¹².

Certifications

Claims products are made in FDA-registered, cGMP facilities (per investor release); BBB Accredited business since Aug 12, 2025 (A+ rating on one listing). ¹⁰¹¹.

Active controversies

Forum debates allege inconsistent third-party testing and incentivized reviews; however, at least some SKUs (e.g., Fisetin) do show independent potency verification. Treat claims as SKU-specific. ⁶⁴.

Astaxanthin 12 mg (AstaReal)

Antioxidant · $24.95 for 60 softgels (listed). [^7].

Strength

Uses AstaReal, a patented, extensively studied astaxanthin raw with numerous human trials; domestic supply chain in WA via AstaReal. ⁷.

Weakness

No posted finished-product potency chromatograms; relies on branded ingredient's evidence rather than brand-run trials. ⁷.

Evidence

Product page cites AstaReal's 70+ human studies; Amazon listing shows 'sold by Double Wood LLC'. ⁷⁸.

Strong pick if you want AstaReal at a competitive price, with the caveat that evidence pertains to the ingredient brand, not Double Wood's lot-level clinicals.

Fisetin 100 mg

Polyphenol/Healthy Aging · $22.95 for 60 caps (listed). [^6].

Strength

Has both a manufacturer COA with HPLC potency and an ISO 17025 third-party potency verification posted (Colmaric Analyticals). ³⁴⁵⁶.

Weakness

Third-party posting is SKU-specific; not clear that every Double Wood product has equivalent potency documentation. ⁶.

Evidence

COA shows 113.5 mg by HPLC; independent lab report shows 'Pass' at 100 mg/cap ±10%. ³⁴.

One of the brand's better-documented items, demonstrating the transparency customers expect.

Magnesium L-Threonate (Magtein)

Mineral/Cognitive Support · $30.95 for 100 x 500 mg caps (listed). [^16].

Strength

Uses Magtein, a branded form with published cognitive data; price is competitive versus well-known alternatives. ¹⁶¹⁷.

Weakness

Page does not consistently provide finished-product potency chromatograms; transparency varies by SKU. ¹⁶.

Evidence

Brand page and Life Extension's Magtein monograph support the form's rationale (cognitive). ¹⁶¹⁷.

Reasonable value route to Magtein if you don't need NSF/USP verification.

Approach with caution

Products with issues

Phosphatidylserine (various counts)

Nootropic/Phospholipid · Varies

Issue

NOW/Eurofins testing (2020 sample set) reported Double Wood PS capsules contained 16%–45% of label claim on the tested lot. ¹⁴.

Avoid until the brand provides robust third-party potency data by lot and addresses the discrepancy.

Magnesium Glycinate '400 mg' front-panel labeling

Mineral · Varies

Issue

Front label '400 mg' refers to compound weight, not elemental—flagged by NaturPro as potentially misleading. ¹⁵.

Check 'elemental magnesium' on the facts panel; consider brands that front-label elemental dose to reduce confusion.

Red flags

Concerning patterns we found

FDA enforcement for disease claims (Dycetin)

2020 FDA Warning Letter classifying Dycetin as an unapproved drug based on cure/mitigation claims. ¹.

FrequencySingle letter identified

ResponseNo public response found on FDA page; resolution status not detailed in the letter.

Prop 65 Notice alleging lead in select botanicals

ERC Notice of Violation filed Feb 19, 2025 naming 4 Double Wood products for lead exposure without warning. ².

FrequencyOne 2025 action; case outcome pending

ResponseNot posted on the brand site at time of review.

Testing methodology clarity

Manufacturer COA footnote cites 'component testing' for result substantiation; best practice is finished-product ID/assay on every lot. ³.

FrequencyObserved on at least one posted COA

ResponseBrand also posts some third-party potency tests (e.g., Fisetin), suggesting partial progress toward best practice. [^4][^6].

Outside test failures on specific products

NOW/Eurofins report listing Double Wood PS underdosing; NaturPro flagging magnesium labeling. ¹⁴¹⁵.

FrequencyIssue-specific; not across the whole catalog

ResponseNo consolidated public rebuttal found.

What customers say

Patterns across the reviews

Service split: fast fixes vs. subscription/ friction

BBB shows both praise and frustration in 2024–2025 posts. ¹²¹¹.

"really impressed with the company and response."

"Very inconsistent and bad quality control."

Customer experience may depend on issue type; confirm terms for subscriptions and consider purchasing direct for support.

Perceived quality variance

Trustpilot contains both satisfied users and claimants of 'no effect' or contamination concerns. ¹³.

"Supplements have no effect whatsoever for us."

"We're very sorry to hear about your concern...please send order details."

Results vary; for sensitive categories, prioritize lots with posted third-party potency PDFs and consider brands with broader certifications.

Counterfeits risk on marketplaces

Forum reports of counterfeit Double Wood products in certain countries via 3rd-party sellers on Amazon; buy from official store or authorized sellers. ¹⁹.

"they don't sell supplements in my country and it is a counterfeit product"

To reduce risk, order direct or from the official Amazon storefront and inspect seals and lot numbers.

Value analysis

What you actually pay for

Pricing strategy

Mid-market with frequent promos (e.g., category BOGOs) and loyalty credits; many single-ingredient SKUs price below premium competitors.

Ingredient cost

Use of branded raws (AstaReal, Magtein) in some SKUs likely elevates COGS but enhances perceived value. ⁷¹⁶.

Markup

Quercetin 500 mg + Bromelain at $24.95/120 (Double Wood) vs. NOW Quercetin+Bromelain ~$23.10–$39.99 suggests competitive or slightly lower mid-range pricing. ¹⁸²⁰²¹²².

Subscription warning

Several BBB complaints surprise subscription renewals and -label disputes; read terms carefully. ¹².

Good-to-very-good value when third-party potency documents are posted for the lot you're buying; weaker value on SKUs with only component-based COAs.

Alternatives

Other brands worth considering

Nootropics Depot

Robust transparency pages, batch COAs compiled by an ISO-accredited partner lab; strong lot-level disclosure culture.

Price

Often higher than Double Wood for comparable nootropics.

Choose when

When third-party documentation depth is your top priority. ²³²⁴.

Thorne

NSF Certified for Sport coverage on many products and strong GMP posture; widely trusted by clinicians and pro sports.

Price

Typically premium vs. Double Wood.

Choose when

For athletes or when you want NSF/third-party program rigor. ²⁶²⁷.

NOW Foods

NPA A-rated GMP certification, extensive in-house and third-party testing, and aggressive category surveillance.

Price

Comparable or lower on many single-ingredient items.

Choose when

Budget-friendly with deep quality infrastructure. ²⁵²⁸²⁹.

Verdict matrix

Who should buy, who should skip

Ideal for

Shoppers who want posted COAs and occasional third-party potency PDFs at mid-market prices
Ingredient-savvy users seeking specific raws (e.g., AstaReal, Magtein) without premium brand markups

Avoid if

You require NSF/USP/USP-Verified or sport certification across your stack
You prefer brands with lot-by-lot finished-product chromatography for every SKU
You're buying from international third-party sellers where counterfeit risk is higher

Best products

Astaxanthin 12 mg (AstaReal)
Fisetin 100 mg
Magnesium L-Threonate (Magtein)

Skip these

Phosphatidylserine until more potency data is posted
Any SKU with only component-based COAs and no finished-product testing visible

The bottom line

Comprehensive analysis shows a nuanced brand. On one side: a visible COA culture and, at least for some products, ISO-17025 third-party potency verification—concrete steps many budget brands still skip. On the other: historical regulatory friction (an FDA Warning Letter for drug claims), a live Prop 65 lead notice on several botanicals, and outside lab reports flagging under-potency or labeling confusion on select items. Bottom line: Double Wood can deliver solid value when you buy SKUs with posted, lot-matched third-party potency PDFs; but risk-averse buyers or athletes needing higher-assurance certifications may prefer alternatives with NSF/USP programs or deeper, uniform batch transparency. ¹²³⁴¹⁴¹⁵.

What to watch for

Watch for outcomes from the 2025 Prop 65 notice (settlement, reformulation, or labeling), any expansion of third-party potency postings across the catalog, and whether Double Wood formalizes certification footprints (e.g., NSF, USP) to match its transparency positioning.

Expert perspectives

NOW Foods' in-house and Eurofins testing report is a credible, detailed third-party benchmark for PS category quality, though it is a 2020 Amazon sample set rather than a 2025 snapshot. ¹⁴.

Frequently asked

Common questions

Does Double Wood test every product in an ISO-accredited third-party lab?

The brand posts COAs for all products and provides third-party potency PDFs for some SKUs (e.g., Fisetin). Others rely on manufacturer COAs and component testing. ³⁴⁶.

Has Double Wood had recalls or FDA actions?

No recalls were found specific to Double Wood. FDA issued a 2020 Warning Letter (disease claims), and a Prop 65 lead notice was filed in 2025 for several botanicals. ¹².

Is Double Wood good value?

Often yes for single-ingredient items (e.g., Quercetin vs. NOW pricing). Value is strongest when your chosen lot has a posted third-party potency PDF. ¹⁸²⁰²¹²².

What should I check before buying?

Open the product page's 'Certificate of Analysis' and 'Third-Party Test Results,' verify lab identity (ISO 17025), and confirm the lot number matches your bottle. ⁴⁵⁶.

Are Amazon purchases safe?

Counterfeits can appear via third-party sellers—especially outside the U.S. Buy direct or from the official Amazon seller and verify seals/lot numbers. ¹⁹.

How we investigated

Document review of FDA enforcement actions and public databases
Analysis of COA PDFs and third-party lab reports linked from product pages
Review of ownership press releases
Price/value comparisons vs. peers
And pattern analysis of verified consumer complaints and discussions across BBB, Trustpilot, and forums.

Sources

1. FDA Warning Letter to Double Wood LLC (Dycetin) (2020)
2. Environmental Research Center – Double Wood Prop 65 Notice (lead) (2025)
3. Double Wood Fisetin – Manufacturer COA (NutraSolutions USA, ISO 17025 no. 113907) (2023)
4. Double Wood Fisetin – Third-Party Certificate of Analysis (Colmaric Analyticals, ISO/IEC 17025 PJLA 86258) (2024)
5. Colmaric Analyticals – Contact (address matches lab report header) (2024)
6. Double Wood Fisetin product page (links to COA and third-party results) (2025)
7. Double Wood Astaxanthin 12 mg (AstaReal) product page (2025)
8. Amazon – Double Wood Astaxanthin (Sold by Double Wood LLC) (2025)
9. LinkedIn – Double Wood Supplements company profile (2025)
10. Boyne Capital acquires majority interest in Double Wood LLC (2021)
11. BBB – Double Wood Supplements (A+, accredited 8/12/2025) (2025)
12. BBB – Complaints for Double Wood Supplements (2025)
13. Trustpilot – Double Wood Supplements reviews (2025)
14. NOW Foods report – Phosphatidylserine testing (includes Double Wood lot) (2020)
15. NaturPro Scientific – The Bad Supplements List (includes Double Wood magnesium glycinate and PS flags) (2023)
16. Magnesium L-Threonate (Magtein) – Double Wood product page and pricing (2025)
17. Life Extension – Neuro-Mag (Magtein) overview (2025)
18. Double Wood Quercetin with Bromelain – product page (2025)
19. Reddit – Counterfeit report outside the U.S. (Double Wood responded brand not selling in that country) (2025)
20. NOW Foods – Quercetin with Bromelain price references (Amazon/Walmart/NOW) (2025)
21. NOW Foods – Quercetin with Bromelain product page price (2025)
22. Walmart – NOW Quercetin with Bromelain pricing (2025)
23. Nootropics Depot – Meet Our Third-Party Labs (2025)
24. Nootropics Depot – Trust Through Transparency (2025)
25. NOW Foods – NPA A-Rated GMP/quality summary (2025)
26. NSF Listings – Thorne Certified for Sport (database) (2025)
27. BusinessWire – Thorne Research Announces NSF Certification (2015)
28. NOW Foods – Going Beyond GMP Quality Assured (2025)
29. NOW Foods – Press release and data on PS category testing (2020)

Investigation date 2025-09-30 · 29 sources