MK-677

1 gram powder Dry-fill capsules - 12.5mg per capsule, 60ct, 750mg total Liquid solution - 25mg per mL, 30mL, 750mg total Tablets - 50mg per tablet, 30ct, 1.5g total

• 1 gram powder Dry-fill capsules - 12.5mg per capsule, 60ct, 750mg total Liquid solution - 25mg per mL, 30mL, 750mg total Tablets - 50mg per tablet, 30ct, 1.5g total

GH release stimulation through GHSR-1a activation, where MK-677 binds the ghrelin receptor with sub-nanomolar affinity (\~0.4 nM) in the hypothalamus and anterior pituitary, reinforcing GHRH signaling while reducing somatostatin's inhibitory action, producing GH output that tracks the body's natural pulsatile rhythm rather than a flat exposure curve. Appetite and caloric-intake signaling, an effect consistently documented across GHSR-1a agonist literature and tracked as a secondary endpoint alongside GH-axis measurements in research protocols. Sleep architecture modulation, with polysomnography research recording increases in slow-wave sleep in younger study subjects and increases in REM sleep in older subjects during prolonged oral exposure, consistent with the known coupling between GH release and sleep stage.

Body composition and lean mass endpoints, examined in a two-year randomized, placebo-controlled trial that found increases in fat-free mass and restoration of GH/IGF-1 levels toward youthful ranges in older adults, alongside a flagged increase in fasting glucose and reduced insulin sensitivity as a monitored limitation. Bone turnover markers, with research reporting increased bone turnover markers in older adults, including those with functional impairment, consistent with the GH/IGF-1 axis's established role in bone remodeling. Neurological and disease-progression endpoints, where a randomized trial testing MK-677 against Alzheimer's disease progression found no clinical effect despite elevated IGF-1 — a null result worth noting alongside the positive findings above.

Metabolic markers, with elevated fasting glucose and reduced insulin sensitivity reported in longer-duration trials and commonly flagged as an endpoint requiring monitoring. Appetite-related effects, with increased hunger signaling consistently reported as a direct consequence of GHSR-1a activation. Cortisol activity, where across human studies GH and IGF-1 elevations were not accompanied by meaningful cortisol increases - a selectivity point that distinguishes MK-677 from some other secretagogues.