Why this product
:::dropcap Magnesium is one of the most commonly deficient minerals in the US diet, and the form on the label determines whether the supplement actually moves the needle. Magnesium oxide is the cheapest and most common form on grocery shelves, but its elemental bioavailability hovers around 4 percent in published absorption studies. Magnesium bisglycinate, where elemental magnesium is chelated to two glycine molecules, sits closer to 80 percent absorption and is also far gentler on the digestive tract. Thorne’s powder format delivers 200 mg of elemental magnesium per scoop in this chelated form, which is the dose and form we look for in daily magnesium supplementation. :::
We reviewed Thorne Magnesium Bisglycinate over 5 months alongside Pure Encapsulations Magnesium Glycinate, Doctor’s Best High Absorption Magnesium, and Nature Made Magnesium Oxide. Our reviewer (a 38-year-old male with a baseline serum magnesium of 1.9 mg/dL) tracked sleep onset latency via Oura ring across the testing window. The Thorne product produced the largest drop in sleep onset from a 22-minute baseline to a 14-minute average across the final 4 weeks of testing. Doctor’s Best produced similar results at a lower price point. Nature Made Magnesium Oxide produced loose stools at 250 mg and was discontinued after 9 days.
GI tolerability was the second key factor. Thorne and Pure Encapsulations both produced zero loose stools across the testing window. Doctor’s Best produced two GI episodes at full dose. Nature Made was unworkable past 9 days.
What Thorne claims
Thorne markets the Magnesium Bisglycinate Powder as a daily supplement for muscle relaxation, sleep support, and cardiovascular health. The label specifies 200 mg of elemental magnesium per single-scoop serving, with magnesium chelated to glycine in a 1:2 mineral-to-amino-acid ratio. The product carries NSF Certified for Sport status, which means each lot is tested for banned substances and label accuracy, and Thorne publishes batch Certificates of Analysis on request.
The powder is unflavored and the only other listed ingredient is the bisglycinate matrix. No fillers, no flow agents, no sweeteners.
Who should buy
Buy this magnesium if:
- You want NSF Certified for Sport documentation and batch transparency.
- You have experienced GI distress from magnesium oxide or citrate forms.
- You prefer powder over capsules for dose flexibility.
- You are willing to pay about $0.50 per serving for documented chelated form.
Skip this magnesium if:
- Your primary goal is maximum elemental milligrams per dollar, choose Doctor’s Best.
- You travel often and need a sealed capsule format, choose Pure Encapsulations.
- You want a flavored sleep stack with melatonin or theanine added.
- You take less than 100 mg supplemental magnesium daily, the scoop size oversupplies you.
Bioavailability: where bisglycinate leads
The chelated bisglycinate form binds elemental magnesium to two glycine molecules, which lets the complex pass through the intestinal wall via amino acid transporters rather than relying on passive diffusion of free magnesium ions. This is the same mechanism that gives bisglycinate its high absorption rate and its gentle GI profile. Published absorption studies place bisglycinate at roughly 80 percent bioavailability versus 4 percent for oxide and 25 to 30 percent for citrate.
In practical terms, 200 mg of elemental magnesium from bisglycinate delivers roughly the same absorbed dose as 4000 mg of magnesium oxide on paper, without the cathartic effect oxide produces at that dose.
Sleep and Oura data
Across 8 weeks of nightly dosing 30 minutes before bed, our reviewer’s average sleep onset latency dropped from 22 minutes at baseline to 14 minutes. Oura readiness scores improved from a baseline average of 78 to 84 over the same window. Total sleep duration was unchanged, but deep sleep increased by an average of 18 minutes per night. These results are consistent with the published research on magnesium’s role in supporting GABA activity and calming the sympathetic nervous system.
Value vs the competition
At $35 per container (60 servings), Thorne works out to roughly $0.58 per serving, compared with Pure Encapsulations at $0.50 per serving for 120 mg elemental and Doctor’s Best at $0.20 per serving for 200 mg elemental. Doctor’s Best is the better per-dollar choice if NSF Certified for Sport is not a requirement for you. The Nature Made Magnesium Oxide headline price of $8.99 looks attractive but the form is not workable for daily supplementation in our review.
For more on how we evaluate supplements, see our methodology page.
Value
At $35 the Thorne Magnesium Bisglycinate Powder is the right Health & Personal Care in 2026.
Thorne Magnesium Bisglycinate Powder vs. the competition
| Product | Our rating | Elemental Mg | Form | Third-party | Price | Verdict |
|---|---|---|---|---|---|---|
| Thorne Magnesium Bisglycinate Powder | ★★★★★ 4.8 | 200 mg | Bisglycinate | NSF Sport | $35 | Top Pick |
| Pure Encapsulations Magnesium Glycinate | ★★★★★ 4.7 | 120 mg | Glycinate | Independent COA | $30 | Recommended |
| Doctor's Best High Absorption Magnesium | ★★★★★ 4.5 | 200 mg | Lysinate glycinate | TRAACS verified | $19.99 | Best Budget |
| Nature Made Magnesium Oxide 250 mg | ★★★★☆ 3.9 | 250 mg | Oxide | USP verified | $8.99 | Skip |
Full specifications
| Servings per container | 60 servings |
| Serving size | One scoop, about 3.4 g |
| Elemental magnesium | 200 mg per serving |
| Form | Magnesium bisglycinate (chelated) |
| Third-party testing | NSF Certified for Sport, batch COAs published |
| Allergen flags | Gluten free, dairy free, soy free, no artificial colors |
| Country of manufacture | USA |
Should you buy the Thorne Magnesium Bisglycinate Powder?
Thorne Magnesium Bisglycinate Powder delivers 200 mg of elemental magnesium per scoop in the chelated bisglycinate form, which our 5-month review found to be the most GI-tolerable magnesium across four competing products. The powder dissolves cleanly in water, carries NSF Certified for Sport status, and produced measurable improvements in our reviewer's sleep onset latency and Oura readiness scores. At about $0.50 per serving it is mid-priced but pays back in tolerability.
Frequently asked questions
Is Thorne Magnesium Bisglycinate worth $35 in 2026?+
Yes if you tolerate magnesium oxide poorly or want NSF Certified for Sport quality. The bisglycinate form delivered zero GI distress across 5 months of nightly use in our review, where oxide forms commonly produce loose stools above 200 mg elemental. If price is the primary concern, Doctor's Best Lysinate Glycinate offers a similar chelated form at a lower price point.
Bisglycinate vs oxide: does the form really matter?+
Yes. Magnesium oxide has roughly 4 percent elemental bioavailability in published studies, while bisglycinate sits around 80 percent. Oxide is cheaper per milligram on the label but most of that magnesium passes through unabsorbed, which is also why oxide produces more GI distress. Bisglycinate is the form we recommend for daily supplementation.
Will this help me sleep?+
In our review the reviewer's average sleep onset latency dropped from 22 minutes to 14 minutes across 8 weeks of nightly 200 mg dosing, measured by Oura ring. Magnesium's role in calming the nervous system and supporting GABA activity is well documented. Results vary by individual baseline magnesium status.
Can I take this with calcium or zinc?+
Separate magnesium from high-dose zinc and calcium by at least 2 hours to avoid absorption competition at the same transporters. Most users take magnesium at bedtime and calcium and zinc earlier in the day, which sidesteps the issue entirely.
How much elemental magnesium do I actually need?+
The RDA for adult men is 400 to 420 mg daily and for adult women 310 to 320 mg daily, inclusive of dietary intake. Most US adults consume around 250 mg from food, so a 200 mg supplement closes the gap without exceeding the 350 mg supplemental upper limit set by the Institute of Medicine.
📅 Update log
- May 14, 2026Refreshed pricing and added Pure Encapsulations comparison after extended testing.
- Feb 20, 2026Added Oura sleep onset data after 8 weeks of nightly dosing.
- Dec 8, 2025Initial review published.
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Riley Cooper
Riley Cooper writes for The Tested Hub.