Comparison
GHRP-2 vs Magnesium L-Threonate
Side-by-side of GHRP-2 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.
GHRP-2
GHRP-2 peptide (pralmorelin, KP-102) is a synthetic hexapeptide ghrelin-receptor agonist that triggers pulsatile growth hormone release via the pituitary.
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
GHRP-2
- •Hexapeptide ghrelin-receptor agonist that stimulates pulsatile GH release within 15 to 30 minutes
- •Strongest appetite signal among GHRPs at standard doses; centrally mediated via NPY/AgRP
- •Produces measurable cortisol and prolactin rise (more than ipamorelin, less than GHRP-6)
- •Approved in Japan as pralmorelin for GH-deficiency diagnostic provocation; not FDA approved
- •Anecdotal protocols use 100 to 300 mcg subcutaneously 2 to 3 times daily on an empty stomach
- •Banned by WADA under S2; detection methods validated in accredited labs
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 | GHRP-2 | Magnesium L-Threonate |
|---|---|---|
| Category | peptide | supplement |
| Also known as | Growth Hormone Releasing Peptide 2, Pralmorelin, KP-102, GPA-748 | Mg-T, MgT, Magtein, magnesium threonate |
| Half-life (hr) ↗ | 0.5 | 4 |
| Typical dose (mg) ↗ | 0.1 | 2000 |
| Dosing frequency | 2-3x daily | 1 to 3 times daily |
| Routes | subcutaneous, intranasal, intravenous | oral |
| Onset (hr) | 0.25 | 1 |
| Peak (hr) | 0.5 | 2 |
| Molecular weight | 817.97 | 294.5 |
| Molecular formula | C45H55N9O6 | C8H14MgO10 |
| Mechanism | Hexapeptide agonist of the growth-hormone secretagogue receptor (GHS-R1a). Suppresses hypothalamic somatostatin tone and stimulates pituitary somatotrophs, producing a pulsatile GH release with secondary cortisol, prolactin, and ACTH elevation. | 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 | Not FDA approved; approved in Japan as pralmorelin (diagnostic); research-use-only grey market in US/EU; banned by WADA | OTC dietary supplement |
| WADA status | banned | allowed |
| DEA / Rx | Not scheduled in US (research chemical); approved diagnostic in Japan | OTC supplement (not scheduled) |
| Pregnancy | Insufficient data; not recommended | Standard magnesium safety; Mg-T-specific data limited |
| CAS | 158861-67-7 | 778571-57-6 |
| PubChem CID | 9919072 | 10691810 |
| Wikidata | Q7235681 | Q27151568 |
Safety profile
GHRP-2
Common side effects
- acute hunger
- head pressure or flushing
- water retention
- vivid dreams
- tingling at injection site
- transient lethargy
Contraindications
- pregnancy
- active malignancy
- history of pituitary tumor
- uncontrolled diabetes
- severe insulin resistance
Interactions
- CJC-1295: synergistic GH release; commonly co-administered for larger pulse(minor)
- sermorelin: additive GH release via parallel GHRH and ghrelin pathways(minor)
- insulin: sustained GH can blunt insulin sensitivity over weeks(moderate)
- corticosteroids: blunt GH response and amplify cortisol load(moderate)
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?
Magnesium L-Threonate comes out ahead for most readers on the criteria we weight: 2 catalogued goals, OTC dietary supplement, oral dosing, with a Tier-B outcome catalogued. GHRP-2 is the right call when one of the conditionals below applies.
- → If your priority is growth-hormone axis, pick GHRP-2.
- → If your priority is post-training recovery, pick GHRP-2.
- → 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.
Edge case: If you want to avoid research-only / gray-market sourcing, Magnesium L-Threonate is the more accessible choice.
Default choice: Magnesium L-Threonate. Lower friction to source, and broader goal coverage. Reach for GHRP-2 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 GHRP-2 and Magnesium L-Threonate?
GHRP-2 and Magnesium L-Threonate differ in category (peptide vs supplement), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, GHRP-2 or Magnesium L-Threonate?
GHRP-2 half-life is 0.5 hours; Magnesium L-Threonate half-life is 4 hours.
Can you stack GHRP-2 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.
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