Comparison
Ipamorelin vs Vitamin D3 + K2
Side-by-side of Ipamorelin and Vitamin D3 + K2. 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.
Ipamorelin
Ipamorelin peptide benefits: selective ghrelin-receptor GHRP, 200 to 300 mcg dosage, GH pulse without cortisol or prolactin rise, CJC-1295 stack vs sermorelin.
Vitamin D3 + K2
Vitamin D3 K2 supplement profile: cholecalciferol at 1000-4000 IU/day corrects deficiency, MK-7 directs calcium to bone, away from arteries.
Effects at a glance
Ipamorelin
- •Pentapeptide GHS-R1a agonist with the cleanest selectivity profile in the GHRP class
- •Minimal cortisol and prolactin elevation at standard doses (substantially less than GHRP-2 or hexarelin)
- •~2 hour plasma half-life, longest of the synthetic GHRPs
- •Largest human safety database (~600 participants in Helsinn's postoperative ileus phase 2)
- •Standard pairing for CJC-1295 no-DAC at 200 to 300 mcg subcutaneously 2 to 3 times daily
- •Banned by WADA under S2; never reached registration despite phase 2b development
Vitamin D3 + K2
- •Reduces non-vertebral fractures 10-20% in older adults at 800 IU/day or above when combined with calcium
- •VITAL trial showed neutral results on primary CV and cancer endpoints at 2000 IU/day over 5 years
- •Vitamin D supplementation reduces respiratory infection incidence ~10-20% in deficient populations
- •K2 MK-7 has 72-hour plasma half-life vs 1-2 hours for MK-4; once-daily dosing is sufficient
- •Synergy hypothesis is largely preclinical; dedicated combination RCTs are limited
- •Daily dosing outperforms bolus dosing for immune and infection outcomes
Side-by-side
| Attribute | Ipamorelin | Vitamin D3 + K2 |
|---|---|---|
| Category | peptide | supplement |
| Also known as | NNC 26-0161, Aib-His-D-2-Nal-D-Phe-Lys-NH2 | cholecalciferol + menaquinone, D3/K2, vitamin D3 with MK-7 |
| Half-life (hr) ↗ | 2 | 360 |
| Typical dose (mg) ↗ | 0.2 | 0.05 |
| Dosing frequency | 2-3x daily | daily with a fat-containing meal |
| Routes | subcutaneous, intravenous | oral |
| Onset (hr) | 0.25 | 24 |
| Peak (hr) | 1 | 168 |
| Molecular weight | 711.86 | 384.64 |
| Molecular formula | C38H49N9O5 | C27H44O (D3); C46H64O2 (MK-7) |
| Mechanism | Selective GHS-R1a agonist that stimulates pulsatile GH release with minimal cortisol or prolactin co-activation. Suppresses hypothalamic somatostatin and stimulates pituitary somatotrophs. | D3 converts to calcidiol then calcitriol, activating the vitamin D receptor (VDR) to increase intestinal calcium absorption and modulate immune and bone gene transcription. K2 carboxylates osteocalcin and matrix Gla protein, directing calcium toward bone and inhibiting vascular calcification. |
| Legal status | Not FDA approved; advanced through phase 2b in postoperative ileus before discontinuation; research-use-only grey market; banned by WADA | Dietary supplement (global) |
| WADA status | banned | allowed |
| DEA / Rx | Not scheduled (research chemical) | Not scheduled |
| Pregnancy | Insufficient data; not recommended | Recommended at standard doses for fetal bone development; consult clinician at higher doses |
| CAS | 170851-70-4 | 67-97-0 |
| PubChem CID | 11338566 | 5280795 |
| Wikidata | Q1666741 | Q139347 |
Safety profile
Ipamorelin
Common side effects
- injection-site irritation
- vivid dreams
- transient mild head pressure
- occasional headache
Contraindications
- pregnancy
- active malignancy
- history of pituitary tumor
- uncontrolled diabetes
Interactions
- CJC-1295: synergistic GH release via parallel GHRH and ghrelin pathways; standard pairing(minor)
- sermorelin: additive GH release; functionally similar pairing to CJC-1295 with shorter GHRH half-life(minor)
- insulin: sustained GH can blunt insulin sensitivity over weeks(moderate)
- corticosteroids: blunt GH response; reduce expected efficacy(moderate)
Vitamin D3 + K2
Common side effects
- GI upset at high doses
- headache (rare)
- hypercalcemia (only at sustained very high D3 doses)
Contraindications
- hypercalcemia
- sarcoidosis
- active hyperparathyroidism
- warfarin therapy (K2 component requires stable intake)
Interactions
- warfarin: K2 component can affect anticoagulation; maintain stable intake and inform anticoagulation clinic(moderate)
- thiazide diuretics: additive calcium retention; hypercalcemia risk with high-dose D3(moderate)
- digoxin and calcium channel blockers: additive effects from D3-induced hypercalcemia(moderate)
- glucocorticoids: reduced vitamin D efficacy and bone effects(moderate)
- cholestyramine and orlistat: bind fat-soluble vitamins; separate dosing by 2 to 4 hours(moderate)
Which Should You Take?
Vitamin D3 + K2 comes out ahead for most readers on the criteria we weight: 3 catalogued goals, OTC dietary supplement, oral dosing, with a Tier-A outcome catalogued. Ipamorelin is the right call when one of the conditionals below applies.
- → If your priority is growth-hormone axis, pick Ipamorelin.
- → If your priority is post-training recovery, pick Ipamorelin.
- → If your priority is bone density, pick Vitamin D3 + K2.
- → If your priority is healthspan extension, pick Vitamin D3 + K2.
Edge case: If you want to avoid research-only / gray-market sourcing, Vitamin D3 + K2 is the more accessible choice.
Default choice: Vitamin D3 + K2. Lower friction to source, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for Ipamorelin 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 Ipamorelin and Vitamin D3 + K2?
Ipamorelin and Vitamin D3 + K2 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, Ipamorelin or Vitamin D3 + K2?
Ipamorelin half-life is 2 hours; Vitamin D3 + K2 half-life is 360 hours.
Can you stack Ipamorelin with Vitamin D3 + K2?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
Go deeper