How We Evaluate Magnesium L-Threonate Supplements

What We Are — And What We Are Not

MagThreonate Brain Lab is a desk-research review site. We are not a lab. We do not run our own assays, send products to ICP-MS analysis, or conduct clinical trials. We are reviewers and editors — not analytical chemists.

Our rankings come from systematic comparison of publicly available evidence: manufacturer Certificates of Analysis (COAs), third-party certification databases (NSF, USP, ConsumerLab, Informed Sport), the peer-reviewed clinical literature on magnesium L-threonate and Magtein®, manufacturer specifications, ingredient transparency, verified customer reviews, and current retail pricing across major US channels.

This transparency matters. A site that claims to test products when it doesn't is harder to trust than one that's clear about being a careful aggregator. Saying "we are not a lab" up-front is, we believe, more credible than fabricated authority.

Our Scoring Rubric

Every Magnesium L-Threonate product we review receives a composite score from 1 to 10, calculated from four weighted sub-scores:

Purity & Magtein® authenticity (30%) — Does the product use patented Magtein® raw material from AIDP, or generic raw magnesium L-threonate? Is there a current COA confirming identity, heavy-metal limits, and microbial purity? We weight this highest because it is the single biggest differentiator between a $35 product and a $90 one.

Bioavailability & delivery format (25%) — Capsule, powder, or liposomal? Does the elemental magnesium dose per serving align with the doses used in the published Magtein® clinical studies (typically 1,500–2,000 mg total compound, ≈144 mg elemental magnesium)? Liposomal and tablet-disintegration data, where available, count here.

Vendor reliability & GMP (25%) — Is the manufacturer cGMP-certified by NSF or a comparable body? Does the company have a clean recall history, transparent contact info, a clearly stated return policy, and consistent third-party retail availability?

Value & dosage adequacy (20%) — Cost per gram of elemental magnesium L-threonate, days-supply at clinical dose, and price stability across major retailers.

What We Do Not Do

• We do not run independent lab assays. We do not commission ICP-MS, HPLC, or microbial testing. When we cite purity data, we cite the source (manufacturer COA, NSF database entry, or published third-party test).
• We do not conduct clinical trials. We summarize the existing peer-reviewed literature on magnesium L-threonate (Slutsky 2010, Liu 2016, Zhang 2024). We do not generate new clinical data.
• We do not run hands-on user trials. We do not pay panels of volunteers to use the products and report results. Our "tolerability" notes aggregate verified customer reviews — they are not from a controlled study.
• We do not accept paid placements. No brand can pay to rank higher, be added to the site, or remove a negative finding.

Our Sources

Where a claim affects scoring or ranking, we cite or link to one or more of:

• The manufacturer's current Certificate of Analysis (where the manufacturer publishes one).
• Independent third-party certification databases: NSF Contents Certified, NSF Sport, USP Verified, ConsumerLab, Informed Sport, Labdoor.
• The AIDP Magtein® brand registry (the patented raw-material supplier).
• Peer-reviewed clinical literature indexed in PubMed.
• Current US retail pricing checked across Amazon, the brand's direct-to-consumer store, iHerb, and Vitacost.
• FDA enforcement records (warning letters, recalls).

Conflicts of Interest

This site is monetized by affiliate commissions. When you click a "Check Current Price" link and purchase, we may receive a percentage of the sale at no extra cost to you. This is disclosed on every review page and in our editorial policy and disclaimer.

Commission rates vary between brands. To avoid skewing rankings toward higher-paying programs, scores are determined before pricing data is reviewed, and any commission-rate disparity is documented in our internal rubric notes. We do not adjust scores to favor higher-paying merchants. If you believe a ranking reflects commission bias, please contact us.

How Often We Update

Reviews are revisited at minimum every six months. Price data is checked monthly. When a new clinical study on magnesium L-threonate is published, we update the relevant explainer posts within four weeks and link the updated content from any affected review.

Every review page shows a visible Published and Updated date. The updated date reflects the most recent material change — pricing, schema, score, or content — not cosmetic edits.

Corrections

We make mistakes. If you spot a factual error — a wrong dose, an out-of-date COA reference, a discontinued SKU — please email us via the contact page. Material corrections are noted at the top of the affected page with the date of correction.