Growth Hormone Releasing Peptide 2 (GHRP-2) is a synthetic peptide. It belongs to a group of compounds called growth hormone secretagogues, which stimulate the body’s own production of growth hormone. GHRP-2 is a hexapeptide, and it was among the first of these secretagogues to be studied in clinical experiments.
Mechanism of Action
GHRP-2 exerts its effects by mimicking the action of ghrelin, a naturally occurring hormone. This synthetic peptide binds to specific receptors known as ghrelin/growth hormone secretagogue receptors (GHSRs), located in the pituitary gland and the hypothalamus in the brain.
Binding to these GHSRs increases intracellular calcium levels within pituitary cells. This action directly stimulates the pituitary gland to release pulses of growth hormone (GH). GHRP-2 also appears to enhance the natural growth hormone-releasing hormone (GHRH) signal transduction pathway and can suppress the actions of somatostatin, a hormone that inhibits GH release.
Reported Physiological Effects
Increased growth hormone levels stimulated by GHRP-2 are associated with several reported physiological outcomes. Users often seek this peptide for its potential for an increase in lean muscle mass. This can occur through enhanced muscle protein synthesis and the activation of satellite cells.
GHRP-2 is also associated with a reduction in body fat, as elevated GH and insulin-like growth factor-1 (IGF-1) levels can promote lipolysis. Improved recovery from exercise is another benefit, as GH and IGF-1 play roles in tissue repair and regeneration. Additionally, some users report enhanced sleep quality and a noticeable increase in appetite.
Associated Health Concerns and Side Effects
Despite its reported benefits, the use of GHRP-2 is linked to several potential negative health consequences. A common and marked increase in hunger can lead to unwanted weight gain for some individuals. Fluid retention is also reported due to elevated GH and IGF-1 levels.
Some users may experience tingling or numbness in the extremities, often attributed to nerve compression from fluid retention or elevated IGF-1. A more serious concern involves GHRP-2’s effect on other hormones; it can cause a slight stimulatory effect on prolactin and cortisol levels. Chronically elevated prolactin may lead to issues such as decreased libido, and in men, gynecomastia, while increased cortisol can induce stress-related symptoms.
Administration and Dosing Protocols
GHRP-2 is typically administered via subcutaneous injection, which involves injecting the peptide just under the skin. Common dosing frequencies involve injections two to three times per day, often spaced six to eight hours apart.
Typical dosage ranges found in online communities suggest between 100 to 300 micrograms (mcg) per injection. The concept of a “saturation dose” suggests that there is a point beyond which increasing the dosage will not yield significantly greater growth hormone release. It is important to remember that this information is for educational purposes only and does not constitute medical advice, as GHRP-2 is not approved for human use.
Regulatory and Safety Status
GHRP-2 is not approved by the U.S. Food and Drug Administration (FDA) for human therapeutic use. It is frequently sold online as a “research chemical” with disclaimers stating it is “not for human consumption.” While purchasing for research purposes may be legal in some regions, marketing or selling it for human consumption or medical treatment is not permitted.
Furthermore, GHRP-2 is listed as a prohibited substance by the World Anti-Doping Agency (WADA). It falls under the category of “GH-Releasing Peptides” and is banned both in and out of competition for athletes. This means that competitive athletes using GHRP-2 risk a positive doping test, highlighting its unapproved status in sports.