Source comparison
MK-677 Help Sarcopenia Research: Comparison
Mechanism Ghrelin receptor agonist. Stimulates endogenous GH/IGF-1 release Direct GH replacement. Bypasses pituitary entirely Androgen receptor activation. Increases protein synthesis Mechanical tension. Stimulates mTOR through mechanotransduction MK-677 prese
This comparison does not assign a generated winner or score.
- Mechanism
- Ghrelin receptor agonist. Stimulates endogenous GH/IGF-1 release
- Direct GH replacement. Bypasses pituitary entirely
- Androgen receptor activation. Increases protein synthesis
- Mechanical tension. Stimulates mTOR through mechanotransduction
- MK-677 preserves lean mass without suppressing endogenous production, but functional gains remain modest versus resistance training
- Lean Mass Gain (12 months)
- +1.1–1.5kg in healthy elderly
- +2.5–3.5kg in deficient adults
- +3–5kg with supraphysiological dosing
- +2–4kg with progressive overload
- Testosterone produces the largest absolute gains, but requires medical oversight due to cardiovascular and prostate risks
- Functional Improvement
- Modest. Grip strength trends positive but inconsistent
- Moderate. Strength gains limited without concurrent training
- Strong. Improves power output and gait speed
- Strong. Consistently improves ADLs and fall risk
- Functional improvement requires mechanical load. No pharmacological intervention matches resistance training for preserving mobility
- Side Effect Profile
- Elevated fasting glucose (+10–15 mg/dL), transient water retention, increased appetite
- Joint pain, carpal tunnel, insulin resistance, elevated cancer biomarkers in long-term use
- Polycythemia, prostate hypertrophy, cardiovascular events in older men
- Delayed-onset soreness, rare musculoskeletal injury
- MK-677 has the mildest side effect profile but carries glucose dysregulation risk in pre-diabetics
- Regulatory Status
- Investigational. Not FDA-approved for any indication
- FDA-approved for adult GH deficiency only
- FDA-approved for hypogonadism
- No approval required. Standard of care
- MK-677 remains unapproved. Clinical use outside trials is off-label and unsupported by regulatory guidance