Comparison
Magnesium L-Threonate vs NMN
Side-by-side of Magnesium L-Threonate and NMN. Every row below is pulled from the compound schema and will update as our data grows. For deeper reads, follow through to each compound page.
Magnesium L-Threonate
Magnesium l-threonate (Magtein) crosses the blood-brain barrier. Typical dose 1,500-2,000 mg. Sleep and cognitive trial data, side effects.
NMN
NMN supplements are oral nicotinamide mononucleotide capsules sold for longevity, energy, and metabolic health. They raise plasma NAD+ 30-90% at 250-1000.
Effects at a glance
Magnesium L-Threonate
- •Distinct magnesium salt designed for blood-brain barrier penetration; not a higher-quality systemic magnesium
- •Liu 2010 rodent study: elevated CSF magnesium ~15% and increased hippocampal synaptic density
- •Trial portfolio in humans is small and mostly Magtein-funded; cognitive effects are modest where reported
- •Typical dose 1500 to 2000 mg/day delivers only ~108 to 144 mg of elemental magnesium
- •GI tolerability comparable to other magnesium forms; loose stools in a minority at 2000 mg/day
- •Distinct from magnesium glycinate, which is the conventional sleep/anxiety/repletion form
NMN
- •Plasma NAD+ rises 30-90% at 250-1000 mg/day across human PK studies
- •Tissue NAD+ rise is inconsistent across human trials (Yoshino 2021, Igarashi 2022)
- •No human trials measure hard endpoints (mortality, CV events, cancer); evidence is biomarker-only
- •Most trials cluster at 250-500 mg/day; dose-response above 250 mg/day is poorly characterized
- •FDA position contested; widely sold as supplement but with regulatory uncertainty
- •Marketing claims for fertility and longevity outrun the human trial evidence substantially
Side-by-side
| Attribute | Magnesium L-Threonate | NMN |
|---|---|---|
| Category | supplement | supplement |
| Also known as | Mg-T, MgT, Magtein, magnesium threonate | nicotinamide mononucleotide, beta-NMN |
| Half-life (hr) ↗ | 4 | 4 |
| Typical dose (mg) ↗ | 2000 | 250 |
| Dosing frequency | 1 to 3 times daily | 1x daily, often morning |
| Routes | oral | oral, sublingual |
| Onset (hr) | 1 | 1 |
| Peak (hr) | 2 | 3 |
| Molecular weight | 294.5 | 334.22 |
| Molecular formula | C8H14MgO10 | C11H15N2O8P |
| Mechanism | Proposed to deliver magnesium across the blood-brain barrier more effectively than other oral salts via threonate-related transporters, raising CNS magnesium and modulating NMDA receptor function and synaptic plasticity. | Direct precursor in the NAD+ salvage pathway; converted to NAD+ by NMNAT enzymes in essentially every tissue. Raised NAD+ supports sirtuin and PARP enzyme activity. |
| Legal status | OTC dietary supplement | Contested in US (FDA position 2022); widely sold as supplement; broadly available in EU, UK, Asia |
| WADA status | allowed | allowed |
| DEA / Rx | OTC supplement (not scheduled) | Not scheduled |
| Pregnancy | Standard magnesium safety; Mg-T-specific data limited | Insufficient data; precautionary avoidance |
| CAS | 778571-57-6 | 1094-61-7 |
| PubChem CID | 10691810 | 14180 |
| Wikidata | Q27151568 | Q418972 |
Safety profile
Magnesium L-Threonate
Common side effects
- loose stools
- mild GI upset
- headache (rare)
- fatigue (rare)
Contraindications
- severe renal impairment (eGFR below 30)
- hypermagnesemia
- myasthenia gravis (high doses)
- concurrent IV magnesium therapy
Interactions
- tetracyclines and fluoroquinolones: magnesium chelation reduces antibiotic absorption; separate by 2 to 4 hours(moderate)
- bisphosphonates: reduced absorption; separate by 2 hours minimum(moderate)
- muscle relaxants and aminoglycosides: potentiated neuromuscular blockade at high doses(moderate)
- antihypertensives: additive blood pressure reduction at high doses(minor)
NMN
Common side effects
- mild GI upset (rare)
- occasional headache
- flushing (rare)
Contraindications
- pregnancy and lactation (precautionary, no data)
- active cancer (theoretical concern, not evidence-based)
Interactions
- metformin: no clinically significant interaction documented; both modulate metabolism through different mechanisms(minor)
- chemotherapy agents: theoretical concern about supporting cancer cell proliferation; coordinate with oncology team(moderate)
- CD38 inhibitors: would amplify NMN-induced NAD+ rise; not clinically relevant for most users(minor)
Which Should You Take?
Magnesium L-Threonate and NMN score evenly on the criteria we weight (goal breadth, legal accessibility, evidence depth). The conditionals below should drive the decision more than any aggregate score.
- → If your priority is focus or working memory, pick Magnesium L-Threonate.
- → If your priority is sleep onset or sleep quality, pick Magnesium L-Threonate.
- → If your priority is healthspan extension, pick NMN.
- → If your priority is energy and stamina, pick NMN.
Edge case: If you want to avoid Contested in US (FDA position 2022); widely sold as supplement; broadly available in EU, UK, Asia, Magnesium L-Threonate is the more accessible choice.
Default choice: either is defensible. Magnesium L-Threonate edges out on goal breadth + legal accessibility; NMN is the right call if your priority sits in the goals listed above.
This verdict is generated from each compound's schema (goals, legal status, evidence outcomes, dosing route). It updates automatically as our compound data evolves; the deeper read sits on each individual compound page.
Common questions
What is the difference between Magnesium L-Threonate and NMN?
Magnesium L-Threonate and NMN differ in category (supplement vs supplement), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Magnesium L-Threonate or NMN?
Magnesium L-Threonate half-life is 4 hours; NMN half-life is 4 hours.
Can you stack Magnesium L-Threonate with NMN?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
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