August 14, 2026

Double Wood Supplements Review 2026 + Top Alternatives

Last updated: September 25, 2026 · Originally published August 14, 2026 · Published by Eternal Elixir

Edited by Elaine Fletcher, Researcher

Quick answer: Double Wood Supplements is a legitimate budget brand founded in 2013 that sells mostly single-ingredient capsules, makes them in US facilities and posts a certificate of analysis on many product pages. It is the cheaper buy for berberine, TUDCA and spermidine per milligram. NMN is where it falls behind. Its Supplement Facts panel lists 250 mg of NMN per two-capsule serving, which works out to $6.53 per gram. Our pick is Eternal Elixir NMN 500mg: 500 mg per capsule, 90 capsules and $1.11 per gram of NMN.

Eternal Elixir makes NMN 500mg and competes with Double Wood, so read this as a competitor’s review. Every Double Wood figure below comes from Double Wood’s own product pages, its posted lab reports or the Supplement Facts panels shown by US retailers, all read on September 25, 2026. We did not buy or test Double Wood products. Here is how we write and review content.

Double Wood Supplements review: who the brand is

Twin brothers Reese and Evan Wood founded Double Wood Supplements in 2013. The company offers a 30-day money-back guarantee. Its store listed just over 200 products and bundles when we checked, and most are single ingredients sold at $19.95 to $39.95 a bottle.

The range is wide. Alongside basics such as magnesium and creatine, it sells many of the longevity actives buyers compare us on: NMN, NMNH, NAD+, AKG, spermidine, TUDCA, resveratrol, pterostilbene, glutathione, berberine, shilajit and Korean ginseng. Its product pages say the capsules are made in the USA in cGMP facilities.

The top search results for this brand are its own testing page, a ConsumerLab summary and a few reviews. A critical Reddit thread ranks too. This review focuses on what the labels and lab reports show, because that is where the real differences are.

How Double Wood tests its supplements

Double Wood’s testing page says every product is third-party tested for identity, potency and purity, and screened for heavy metals and microbes. The newer product pages go further than most budget brands. Each one we read links a certificate of analysis for the current lot, and most also show the results table, the lab and the lot number on the page:

Berberine: lot 2601-22, made March 2026, tested by Brand International. The label claim is 500 mg of berberine HCl, and the result was 600 mg.
TUDCA: lot 2534500, made February 2026, tested by Brand Nutraceuticals. The result was 525.16 mg against a 450 to 550 mg specification.
Spermidine: lot AILAB, made March 2026, tested by Canyonside Labs. The result was 10.2 mg of spermidine trihydrochloride against a 10 mg claim for a two-capsule serving.

The product pages say these tests are run by labs accredited to ISO/IEC 17025. ConsumerLab’s public page says it has tested seven Double Wood products. Five passed its quality review, two of them as Top Picks, and two did not pass. The page does not name which products fell into each group without a membership.

For a budget brand, this is strong disclosure. Posting the lot and the result on the page lets you check the bottle you receive, and we would like to see more brands do it.

Double Wood vs Eternal Elixir: doses and prices

Bottle prices are close, but the dose per capsule and the number of capsules are not. These are the single-bottle prices on each brand’s US store as of Sep 2026. Double Wood capsule counts come from the Supplement Facts panels on retailer listings, because its own pages do not state them in text.

Active	Eternal Elixir	Double Wood
NMN	NMN 500mg: 500 mg per capsule, 90 capsules, $49.99. That is $0.56 per capsule and $1.11 per gram of NMN.	NMN: 250 mg per two-capsule serving, 60 capsules, 30 servings, $48.95. That is $1.63 per serving and $6.53 per gram of NMN.
Spermidine	Spermidine 10mg: 10 mg spermidine trihydrochloride per capsule, 60 capsules, $49.99. That is $0.83 per 10 mg.	Spermidine: 5 mg spermidine trihydrochloride per capsule, 120 capsules, $39.95. That is $0.67 per 10 mg (two capsules).
TUDCA	TUDCA 500mg: one capsule per serving, 60 capsules, $59.99. That is $1.00 per serving.	TUDCA: 500 mg per two-capsule serving, 60 capsules, 30 servings, $27.95. That is $0.93 per serving.
Berberine	Berberine HCl 500mg from a 20:1 extract: one capsule per serving, 90 capsules, $49.99. That is $0.56 per serving.	Berberine: 500 mg berberine HCl per capsule, 60 capsules, $19.95. That is $0.33 per capsule.
Tongkat ali	Tongkat Ali 200:1 Extract 2000mg: 2,000 mg per three-capsule serving, 90 capsules, $29.99. That is $1.00 per serving.	Tongkat Ali Extract: 1,000 mg of 200:1 extract plus 20 mg of tribulus per two-capsule serving, $29.95.

Add NMN 500mg to cart · $49.99

A note on the NMN row. One line on Double Wood’s NMN page says each capsule delivers 250 mg, but the rest of the page and the Supplement Facts panel say 250 mg per serving of two capsules. We used the panel. If your bottle’s panel says otherwise, the per-gram figure halves to about $3.26, which is still close to three times ours.

Where Double Wood wins

We would rather say this plainly. On four of the five rows, Double Wood costs less per milligram.

Berberine. The same 500 mg of berberine HCl per capsule for $0.33 against our $0.56. If berberine is all you need, Double Wood is the value pick, and its latest lot tested above the label claim.
TUDCA. $0.93 per 500 mg serving against our $1.00. You take two capsules instead of one.
Spermidine. Both brands use spermidine trihydrochloride, so the milligrams compare directly. Double Wood costs $0.67 per 10 mg against our $0.83, and you take two capsules instead of one. Its directions allow 5 to 20 mg a day, which suits anyone who wants to start low.
Lab reports on the page. Double Wood posts the lot number, the lab and the result for each product we checked.

Its range is also broader. It sells magnesium, nattokinase and many nootropics that we do not carry.

Where Eternal Elixir wins

NMN value. One of our capsules holds 500 mg of NMN. A 90-capsule bottle holds 45,000 mg for $49.99, and a Double Wood bottle holds 7,500 mg for $48.95 on its panel. Our NMN supplement comparison runs the same per-gram maths across other US brands.
One capsule per serving. Our TUDCA gives 500 mg in one capsule and our spermidine gives 10 mg in one capsule, where Double Wood needs two of each.
Tongkat ali dose. Our serving declares 2,000 mg of 200:1 extract, twice the 1,000 mg in a Double Wood serving, for a similar bottle price. Double Wood sells tongkat ali and fadogia as separate bottles at $29.95 each. We also sell Tongkat Ali + Fadogia 2010mg as one formula, 90 capsules for $19.99, or $0.67 per serving.
Evidence labels. Our product pages state an evidence level for each active and say what has not been shown.

Buying two or more bottles of any of ours takes 10% off two, 15% off three and 20% off five, and US orders over $100 ship free.

What the research says about these doses

NMN: small human trials, blood NAD+ markers

A University of Tokyo trial published in npj Aging in 2022 (Igarashi and colleagues) gave healthy older men 250 mg of NMN a day or a placebo for 6 or 12 weeks. Blood NAD+ and related compounds rose on NMN. Changes in gait speed and grip strength were only nominally significant, and the authors said larger studies are needed. That 250 mg a day is the amount on Double Wood’s panel.

A dose-ranging trial in GeroScience in 2023 (Yi and colleagues) randomized 80 healthy middle-aged adults to a placebo or to 300 mg, 600 mg or 900 mg of NMN a day for 60 days. Blood NAD+ rose in every NMN group and was highest at 600 mg and 900 mg, and no safety issues were found up to 900 mg. Three of the authors were employees of chemical companies, which is worth knowing when you read the results. One of our capsules is 500 mg, between the 300 mg and 600 mg arms.

Evidence level: small randomized human trials that measured blood NAD+ and short-term function. NMN has not been shown to extend human lifespan. Our NAD+ supplement guide compares NMN with nicotinamide riboside.

Spermidine: one long trial, primary goal missed

The SmartAge trial in JAMA Network Open (Schwarz and colleagues, 2022) gave 100 adults aged 60 to 90 with subjective cognitive decline either 0.9 mg of spermidine a day from wheat germ extract or a placebo for 12 months. Memory performance, the primary outcome, did not change significantly compared with placebo. Both brands’ products supply more spermidine than that trial used, and no human trial has shown that a higher dose works better.

Evidence level: limited. Buy spermidine for a clearly labeled dose of a polyamine, not for a promised result. Our spermidine supplement comparison lines up the doses across brands.

TUDCA: one small trial at a much higher dose

A four-week randomized trial at Washington University in St. Louis (Kars and colleagues, 2010) gave 20 adults with an average body mass index of 37 either 1,750 mg of TUDCA a day or a placebo. Insulin sensitivity in the liver and muscle rose by about 30% on TUDCA and did not change on placebo. Fat tissue did not respond. That trial dose is three and a half times the 500 mg serving of either brand, so neither label dose has been tested in that design.

Evidence level: one small human trial. Our TUDCA supplement comparison covers the doses and brands on sale in the US.

Add TUDCA 500mg to cart · $59.99

Top alternatives to Double Wood Supplements

We ranked these for longevity buyers, with our own range first. Eternal Elixir makes the products in item 1, and they are our pick. The other three are real options with different strengths.

1. Eternal Elixir: best for NMN and one-capsule servings

NMN 500mg gives 500 mg per capsule and 45,000 mg per bottle for $49.99, or $1.11 per gram. Our TUDCA and spermidine each give a full serving in one capsule. Suits: buyers who want fewer capsules and the lowest price per gram of NMN. Doesn’t suit: anyone who wants the cheapest berberine or TUDCA per milligram.

2. Solaray: best for a long return window

Solaray sells NMN at 500 mg per VegCap, 60 VegCaps for $38.19, or $1.27 per gram. It offers a 60-day money-back guarantee and runs its own testing lab in Utah. Suits: buyers who want NMN at 500 mg per capsule from a long-running mainstream brand. Doesn’t suit: anyone who needs TUDCA, which it does not sell. Our Solaray review has the full breakdown.

3. Nootropics Depot: best for 500 mg TUDCA per capsule

Nootropics Depot sells TUDCA capsules at 500 mg per capsule, 30 capsules for $29.99, and links signed lab-testing PDFs for each size. Suits: buyers who want TUDCA in one capsule at a low price per serving. Doesn’t suit: buyers who want more than a month in the default bottle, since the 120-capsule size costs $89.99.

4. Nutricost: best for low entry prices

Nutricost sells TUDCA at 250 mg in 30 or 60 capsules ($19.97 or $27.97) and at 500 mg in 30 capsules ($28.97), one capsule per serving, and says its products go through third-party testing at an ISO-accredited lab. Suits: buyers who want to try a low dose cheaply. Doesn’t suit: buyers who want 500 mg from one capsule at the lowest price, since the 250 mg sizes need two capsules for that amount. Our Nutricost review covers the rest of its range.

For other brand comparisons, our Thorne review and Life Extension review cover two premium brands, and our NOW Foods review covers another large range sold on value. If berberine is your main purchase, our berberine supplement guide compares the forms on sale. For glutathione, our glutathione comparison lines up several brands, and our Reduced L-Glutathione 2000mg gives 2,000 mg per two-capsule serving for $39.99.

Double Wood Supplements review: frequently asked questions

Is Double Wood a reputable supplement brand?

Yes. It has sold supplements since 2013, posts outside lab results with lot numbers on many product pages and offers a 30-day money-back guarantee. ConsumerLab’s public page says five of the seven Double Wood products it tested passed its quality review and two did not. Check the certificate for the lot you buy, as you would with any brand.

Are Double Wood supplements third-party tested?

Double Wood says every product is third-party tested, and its newer product pages show results from outside labs such as Brand International, Brand Nutraceuticals and Canyonside Labs, with a lot number and a link to the full certificate. Its general testing page also says certificates are available on request.

Where are Double Wood supplements made?

Its product pages say the supplements are manufactured in the USA in cGMP facilities. The pages we read do not say where each raw ingredient comes from, so ask Double Wood if origin matters to you for a specific product.

What are people saying about Double Wood Berberine?

We don’t summarize customer reviews here, but the product facts are clear. It contains 500 mg of berberine HCl per capsule, 60 capsules for $19.95, and the latest posted lot tested at 600 mg against the 500 mg claim. Double Wood’s directions say to start with one capsule a day with food and increase slowly to limit stomach upset, up to three capsules a day. If you take prescription medicine, talk to your doctor before starting berberine.

What about Double Wood Nattokinase?

Double Wood’s nattokinase gives 4,000 fibrin units per two-capsule serving for $19.95. The page says an ISO/IEC 17025 lab checks enzyme activity on every batch. If you take a blood-thinning medicine or have surgery coming up, talk to your doctor before taking nattokinase. We do not sell nattokinase.

What is the highest-rated supplement in the world?

There isn’t one. Ratings depend on the site, the product and who is reviewing. A more useful test is whether the label states the exact dose, whether that dose matches human trials, whether an outside lab tested the lot and whether the brand says what hasn’t been shown.

Which is better value, Double Wood or Eternal Elixir?

It depends on the ingredient. Double Wood is cheaper per milligram for berberine, TUDCA and spermidine. Eternal Elixir is far cheaper per gram of NMN, at $1.11 against $6.53 on Double Wood’s panel, and gives a full serving of TUDCA or spermidine in one capsule. Compare the milligrams per serving first, then divide the price by the number of servings.

What is the best alternative to Double Wood NMN?

Our pick is Eternal Elixir NMN 500mg, which we make. It declares 500 mg of NMN per capsule on the front label, holds 90 capsules, or 45,000 mg of NMN, and costs $49.99, about $1.11 per gram.