Comparison
Alpha-GPC vs Magnesium L-Threonate
Side-by-side of Alpha-GPC and Magnesium L-Threonate. 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.
Alpha-GPC
Alpha GPC supplement profile: 300 to 600 mg dosage, acetylcholine synthesis, attention and reaction-time evidence, side effects, and choline donor comparisons.
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.
Effects at a glance
Alpha-GPC
- •Choline donor supplement, roughly 40% choline by weight; crosses blood-brain barrier efficiently
- •Replicated small gains in attention and reaction time at 300 to 600 mg in healthy adults
- •Standard prescription cognitive medication in much of Europe (Gliatilin) at 1,200 mg/day for vascular cognitive impairment
- •ASCOMALVA trial (n=210) showed cognitive preservation when added to donepezil over 24 months
- •Increases acute power output (~14%, single trial) and transient growth hormone secretion at 600 mg
- •TMAO production raises a contested cardiovascular concern at chronic high doses
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
Side-by-side
| Attribute | Alpha-GPC | Magnesium L-Threonate |
|---|---|---|
| Category | supplement | supplement |
| Also known as | L-Alpha glycerylphosphorylcholine, choline alfoscerate, GPC, alpha-glyceryl phosphorylcholine | Mg-T, MgT, Magtein, magnesium threonate |
| Half-life (hr) ↗ | 4 | 4 |
| Typical dose (mg) ↗ | 600 | 2000 |
| Dosing frequency | 1 to 3 times daily | 1 to 3 times daily |
| Routes | oral | oral |
| Onset (hr) | 1 | 1 |
| Peak (hr) | 2 | 2 |
| Molecular weight | 257.22 | 294.5 |
| Molecular formula | C8H20NO6P | C8H14MgO10 |
| Mechanism | Hydrolyzed to free choline and glycerophosphate after absorption; choline supports acetylcholine and phosphatidylcholine synthesis in CNS. | 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. |
| Legal status | Dietary supplement (US); prescription medication in much of Europe | OTC dietary supplement |
| WADA status | allowed | allowed |
| DEA / Rx | OTC supplement | OTC supplement (not scheduled) |
| Pregnancy | Insufficient data; choline generally recommended in pregnancy | Standard magnesium safety; Mg-T-specific data limited |
| CAS | 28319-77-9 | 778571-57-6 |
| PubChem CID | 71920 | 10691810 |
| Wikidata | Q411478 | Q27151568 |
Safety profile
Alpha-GPC
Common side effects
- mild GI upset
- headache
- dizziness
- occasional insomnia with evening dosing
Contraindications
- established cardiovascular disease (TMAO concern)
- concurrent strong anticholinergic therapy
Interactions
- anticholinergic medications: partial mutual antagonism(minor)
- cholinesterase inhibitors (donepezil): additive cholinergic effect, basis for ASCOMALVA protocol(minor)
- scopolamine: partial counteraction of anticholinergic effect(minor)
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)
Which Should You Take?
Alpha-GPC comes out ahead for most readers on the criteria we weight: 3 catalogued goals, OTC dietary supplement, oral dosing, with a Tier-B outcome catalogued. Magnesium L-Threonate is the right call when one of the conditionals below applies.
- → If your priority is athletic performance, pick Alpha-GPC.
- → If your priority is choline supply, pick Alpha-GPC.
- → If your priority is sleep onset or sleep quality, pick Magnesium L-Threonate.
Default choice: Alpha-GPC. Lower friction to source, and broader goal coverage. Reach for Magnesium L-Threonate only if your priority sits squarely in the goals it owns 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 Alpha-GPC and Magnesium L-Threonate?
Alpha-GPC and Magnesium L-Threonate 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, Alpha-GPC or Magnesium L-Threonate?
Alpha-GPC half-life is 4 hours; Magnesium L-Threonate half-life is 4 hours.
Can you stack Alpha-GPC with Magnesium L-Threonate?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
Go deeper