GHRP-6

GHRP-6 acts as a potent and selective agonist of the growth hormone secretagogue receptor (GHS-R1a), a G protein-coupled receptor primarily located in the hypothalamus and pituitary gland. Upon binding to this receptor, GHRP-6 triggers an intracellular signaling cascade involving phospholipase C (PLC) activation and calcium mobilization, leading to GH release from anterior pituitary somatotrophs. Unlike GHRH, which acts via the GHRH-R, GHRP-6 potentiates GH response even in the presence of somatostatin (GH inhibitor). Additionally, it stimulates cortisol and prolactin release and has orexigenic effects (increased appetite) mediated by activation of NPY/AgRP neurons in the hypothalamus.

• Target receptor: GHS-R1a (ghrelin receptor)
• Primary mechanism: PLC activation, intracellular calcium increase, GH release
• Additional effects: Stimulation of cortisol, prolactin, and appetite

• Muscle growth research: Used in studies to increase muscle mass and strength, though without clinical approval.
• Anti-aging: Explored for potential to improve body composition and reduce fat, but lacking solid human evidence.
• Appetite stimulation: Investigated to induce appetite in patients with cachexia or eating disorders.
• Pituitary function studies: As a diagnostic tool to assess GH reserve in the pituitary gland.

The effects of GHRP-6 include a significant increase in growth hormone (GH) and insulin-like growth factor 1 (IGF-1) levels, which can promote protein synthesis, lipolysis, and tissue growth. Increased appetite has also been observed, possibly due to activation of orexigenic pathways. Other reported effects in studies include improved bone density, increased muscle strength, and enhanced sleep quality. However, these effects are variable and depend on dose and treatment duration.

GHRP-6 is not approved by the FDA or EMA for human use, and its use is restricted to research. Potential adverse effects include increased appetite (which may lead to weight gain), fluid retention, joint pain, fatigue, and hormonal imbalances such as elevated prolactin and cortisol. It may also cause transient hyperglycemia. Due to the lack of long-term studies, the risks of chronic use are not fully understood. It is contraindicated in individuals with active cancer, uncontrolled diabetes, severe heart disease, and in pregnant or lactating women. Extreme caution is advised, and use should only occur under medical supervision in research settings.

GHRP-6 is not approved by the FDA (USA), EMA (Europe), or other major regulatory agencies for clinical human use. It is classified as a research substance and is not available as a prescription medication. In some countries, it may be regulated as a growth hormone analog and subject to sports use restrictions (banned by WADA).

In research, typical doses range from 100-300 mcg subcutaneously, 1-3 times daily, usually in cycles of 8-12 weeks. However, there is no standardized approved dosage for humans. It is recommended to start with low doses and adjust based on response and tolerance, always under medical supervision.

Lyophilized GHRP-6 should be stored in a cool, dry place, protected from light, at a temperature between 2-8°C (refrigerated). Once reconstituted with bacteriostatic water or sterile saline, it should be kept refrigerated and used within 7-14 days to avoid degradation. Do not freeze the reconstituted solution.