Contraindications: MK-677 is not appropriate for individuals with active malignancies or a personal history of hormone-sensitive cancers, as GH and IGF-1 elevation can promote cellular proliferation. Individuals with pre-existing insulin resistance or type 2 diabetes should not use this compound without endocrinological supervision; ghrelin receptor activation is associated with transient fasting glucose elevation. Not for use by persons under 21 years of age, pregnant individuals, or nursing mothers.
Side_Effects: The most frequently reported effects are dose-dependent: increased appetite (very common, onset within 1 week), fluid retention and peripheral oedema (common, typically mild to moderate), and transient increases in fasting blood glucose. Some users report lethargy or mild fatigue during the first 2 weeks of use, attributable to elevated GH activity. Elevated IGF-1 may contribute to joint aches or carpal tunnel-type discomfort at higher doses (20–25mg/day).
Monitoring: Monitor fasting blood glucose and HbA1c at baseline and every 6–8 weeks during a cycle; MK-677 demonstrably impairs insulin sensitivity in a dose-dependent manner. Track serum IGF-1 to confirm therapeutic elevation and avoid supraphysiological overshoot. Body weight and blood pressure should be assessed weekly during the first month. Discontinue if oedema becomes symptomatic or fasting glucose rises above 100 mg/dL without prior elevation.
PCT: MK-677 does not suppress testosterone production or the hypothalamic–pituitary–gonadal axis; formal post-cycle therapy with SERMs is therefore not required after a standalone MK-677 cycle. GH and IGF-1 levels return to pre-cycle baseline within approximately 1 week of cessation. If MK-677 was stacked with androgenic compounds, PCT should address the androgenic component according to standard protocols.