Source comparison
MK-677 for Natural GH Elevation Research: Study Design Comparison
The table below compares key parameters across major MK-677 clinical trials examining metabolic and body composition endpoints. Understanding these design differences is critical when interpreting published results or designing new protocols. Chapman et al. (1
This comparison does not assign a generated winner or score.
- The table below compares key parameters across major MK-677 clinical trials examining metabolic and body composition endpoints. Understanding these design differences is critical when interpreting published results or designing new protocols.
- Chapman et al. (1996), JCEM
- Healthy young adults (n=32)
- 25 mg daily, 8 weeks
- Body composition (DEXA)
- +89% vs baseline
- Lean mass +1.8 kg, fat mass −0.4 kg (not significant)
- Short duration limits body composition signal; IGF-1 response validates mechanism
- Svensson et al. (1998), JCEM
- GH-deficient adults (n=24)
- 25 mg daily, 4 weeks
- GH secretion pulsatility
- +127% 24-hr GH AUC
- Preserved pulsatile pattern, no hypothalamic suppression
- Demonstrates non-suppressive mechanism vs exogenous GH
- Nass et al. (2008), Ann Intern Med
- Elderly adults (n=65)
- 25 mg daily, 12 months
- Lean body mass, fat mass
- +72% at 12 months
- Lean mass +1.1 kg, visceral fat −1.1 kg, fasting glucose +5 mg/dL
- Longest-duration trial; glucose elevation requires monitoring
- Murphy et al. (2009), Growth Horm IGF Res
- Obese males (n=18)
- Visceral adipose tissue
- +61% vs baseline
- VAT −8.2%, subcutaneous fat unchanged
- GH-driven lipolysis preferentially targets visceral depots
- Johannsson et al. (2001), JCEM
- Elderly frail subjects (n=292)
- 25 mg daily, 24 months
- Physical function, bone density
- +68% sustained
- No improvement in functional endpoints despite IGF-1 rise
- IGF-1 elevation alone insufficient for frailty reversal