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NOW Foods vs Double Wood Magnesium L-Threonate (2026)
Disclosure: We earn commissions on purchases made through our links. This never influences our scores. Editorial policy
The Verdict
These two are essentially tied on our rubric - Double Wood posts an 86 execution score to NOW Foods' 85 on our 0-100 scale. Both cost about $1.00-$1.03 per day at the full 2000mg Magtein dose. Double Wood carries the Best Value badge in our magnesium L-threonate scoring and publishes ISO-accredited COAs; NOW Foods brings NPA A-rated GMP manufacturing. In our view this is a near tie between two same-form, same-price products - Double Wood for the published COAs and slight score edge, NOW Foods for its established GMP program.
NOW Foods Magtein Magnesium L-Threonate
NOW Foods
Double Wood Supplements Magnesium L-Threonate
Double Wood Supplements
Head-to-Head Comparison
| Category | NOW Foods Magtein Magnesium L-Threonate NOW Foods | Double Wood Supplements Magnesium L-Threonate Double Wood Supplements |
|---|---|---|
| Brand Score | 85/100 | 86/100Winner |
| Dosing & Form | 25/25Winner | 25/25 |
| Purity | 20/25Winner | 19/25 |
| Value | 20/25 | 22/25Winner |
| Transparency | 20/25Winner | 20/25 |
| Cost/Day | $1.03 | $1.00Winner |
| Dose/Serving | 2000mg | 2000mg |
| Form | magnesium L-threonate (Magtein) | magnesium L-threonate (Magtein) |
| Third-Party Tested | ✓ Yes | ✓ Yes |
| Proprietary Blend | No | No |
Why This Comparison Matters
NOW Foods and Double Wood both use Magtein magnesium L-threonate at the full 2000mg dose, so the active ingredient and dose match. NOW Foods brings its NPA A-rated GMP manufacturing; Double Wood publishes ISO-accredited COAs and markets itself as a transparency-forward value brand. This is a value-tier matchup where both share the same researched form.
Because both use Magtein at 2000mg, the cognitive research applies equally. The decision is about testing documentation and cost per day.
We scored both on evidence, quality, cost per dose, and transparency.
Detailed Score Breakdown
NOW Foods Magtein Magnesium L-Threonate
NOW Foods
2,000mg Magtein per 3-capsule serving - correct clinical dose
NPA A-rated GMP facility. In-house ISO testing plus selective third-party testing. NOW Foods is a reliable mid-tier brand.
$1.03/day at 2,000mg Magtein
Magtein trademark listed. Standard label disclosure.
Solid NOW Foods quality at a fair price. NPA A-rated GMP is a meaningful quality credential.
Double Wood Supplements Magnesium L-Threonate
Double Wood Supplements
2,000mg Magtein per 3-capsule serving - correctly dosed at the clinical threshold
ISO-accredited COAs available. GMP certified facility. Less established brand than Life Extension or Sports Research.
$1.00/day - tied with Sports Research for best value in the category
Magtein form identified. Clear dosing information. Minimal excipients.
Same $1.00/day cost as Sports Research without the NSF certification. Good option for cost-focused buyers who want authentic Magtein.
How We Compared These Products
Every product in our database is scored on four equally-weighted pillars: dosing accuracy and form quality, purity verification (third-party testing), cost per clinically effective dose (not cost per pill), and label transparency. Each pillar is worth 25 points for a total of 100.
Cost per effective dose is calculated using the clinically studied dose from published research, not the manufacturer's suggested serving. If a product requires multiple servings to reach the dose used in clinical trials, that cost is reflected in the value score.
For a full explanation of our scoring methodology, see our methodology page. Prices were last checked on the dates listed for each product and may have changed.
More Magnesium L-Threonate Comparisons
We earn commissions on purchases made through our links. This never influences our scores or recommendations. See our editorial policy.
FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. Dietary supplements are not intended to diagnose, treat, cure, or prevent any disease. Always consult with a qualified healthcare professional before starting any supplement regimen.