Source comparison
MK-677 Nitrogen Retention: Research Compound Comparison
MK-677 Ghrelin receptor agonist 23–31% (sustained) Pulsatile GH + basal elevation; IGF-1 remains elevated 16–20 hrs Once daily (oral) Best option for long-duration studies requiring consistent nitrogen retention without injection protocols or endogenous suppre
This comparison does not assign a generated winner or score.
- MK-677
- Ghrelin receptor agonist
- 23–31% (sustained)
- Pulsatile GH + basal elevation; IGF-1 remains elevated 16–20 hrs
- Once daily (oral)
- Best option for long-duration studies requiring consistent nitrogen retention without injection protocols or endogenous suppression
- Exogenous GH
- Direct GH replacement
- 18–25% (variable)
- Supraphysiological peak, suppresses endogenous pulses
- Daily subcutaneous injection
- Higher cost, requires injection compliance, suppresses natural GH production. Less suitable for studies examining endogenous regulation
- Testosterone (research)
- Androgen receptor agonist
- 15–22%
- IGF-1 elevation secondary to AR activation
- Varies (injection or transdermal)
- Confounds nitrogen data with androgenic effects; useful for androgen-specific pathways but not ideal for isolating GH/IGF-1 mechanisms
- CJC-1295/Ipamorelin
- GHRH + GHRP analogs
- 12–18%
- Pulsatile GH only, shorter IGF-1 elevation window
- Multiple daily injections
- Requires more frequent dosing; nitrogen retention lower than MK-677 due to shorter IGF-1 exposure
- Leucine supplementation
- mTOR activator (dietary)
- 5–9%
- No GH/IGF-1 effect
- Multiple daily doses with meals
- Weakest nitrogen retention; useful as adjunct but insufficient as primary intervention in catabolic states