GHRP-2 Guía & Tabla de Dosis

What is GHRP-2?

GHRP-2 stands for Growth Hormone-Releasing Peptide 2. Its clinical research name is pralmorelin. It is a small, synthetic peptide — just a short chain of amino acids — created by researchers at Tulane University and Polygen in Germany.^[1] Scientists designed it to mimic ghrelin, a natural hormone produced in the gut that tells the brain to release growth hormone (GH) and to feel hungry.^[2]

GHRP-2 is a research-use-only compound. It is not an approved drug for general human use in most countries, though it has been studied in clinical trials as a diagnostic tool for growth hormone deficiency.^[1] It appears on the World Anti-Doping Agency (WADA) Prohibited List, and sports drug-testing labs have developed urine tests to detect it in athletes.^[3]

How GHRP-2 Works

Think of your pituitary gland — a pea-sized gland at the base of your brain — as a factory that makes growth hormone. GHRP-2 is like a doorbell for that factory. When it rings, the factory ramps up production and releases a pulse of GH into the bloodstream.^[1]

More specifically, GHRP-2 binds to a receptor called the GH secretagogue receptor (GHS-R) — the same receptor that ghrelin uses.^[2] Importantly, research has confirmed that GHRP-2 does not work through the separate growth hormone-releasing factor (GRF) receptor, meaning it has its own distinct signaling pathway.^[5] This distinction matters to scientists studying exactly how GH release is controlled.

Beyond the pituitary, GHS-R receptors also exist on muscle cells. Lab studies show that GHRP-2 can act directly on muscle tissue, dialing down the activity of proteins called Atrogin-1 and MuRF1 — molecules that break down muscle fiber during stress or illness.^[4] This finding has sparked interest in GHRP-2 as a research tool for understanding muscle wasting.

What the Research Shows

Here is a plain-language summary of key findings from published studies:

• GH release in healthy people: Early research established that GHRP-2 reliably raises GH levels in healthy men and women regardless of age, sex, or body weight. In people with true GH deficiency, the GH response is much blunter — a difference researchers used to set a diagnostic cut-off value.^[1]
• Appetite increase in humans: In a controlled human study, seven healthy lean men received a slow subcutaneous infusion of GHRP-2 or a saline placebo, then sat down to a freely available buffet. The men ate about 36% more calories during the GHRP-2 infusion compared to placebo — and every single subject ate more, not just the average.^[2] This mirrors what is seen with ghrelin itself, confirming that GHRP-2 activates appetite circuits as well as GH release.^[2]
• Muscle protection in the lab: Cell culture and animal studies found that GHRP-2 reduced the expression of muscle-breakdown genes triggered by the stress hormone dexamethasone, and that this protective effect was blocked when researchers used a GHS-R blocker — confirming the receptor pathway is essential.^[4]
• Anti-doping detection: Sports testing researchers have shown that GHRP-2 and its breakdown products can be detected in urine for up to roughly 47 hours after nasal administration, making it trackable in doping control.^[6] Labs have validated mass spectrometry methods to find GHRP-2 and related peptides in athlete urine samples.^[3]
• Diagnostic use: Under the research name KP-102D, pralmorelin was studied in Japan as a diagnostic agent for hypothalamo-pituitary function, with approval applications submitted as of the early 2000s.^[1]

What GHRP-2 Is Being Studied For

Researchers have investigated GHRP-2 across several areas:

• Diagnosing GH deficiency — using a single standardized dose to see whether the pituitary responds normally^[1]
• Understanding appetite and eating behavior — as a pharmacological tool to probe how ghrelin-like signals influence food intake in humans^[2]
• Muscle atrophy and wasting — exploring whether GHS-R activation in muscle cells can slow breakdown processes^[4]
• Preclinical growth research — tested in animal models including swine and yaks to study GH release and growth performance
• Anti-doping science — developing detection methods to identify misuse in sport^[3][6]

How GHRP-2 Is Dosed in Research

Doses vary widely depending on the research question, the species being studied, and the route of administration. Human studies have used everything from microgram-level injections to milligram-level oral doses in animal models. Rather than restate every number here, please refer to the dosage chart on this page for a full breakdown of protocols from published trials — and use the calculator to work out weight-based amounts for any specific research protocol. All dosing information is provided strictly for reference purposes.

Mixing and Storing GHRP-2

GHRP-2 is typically supplied as a lyophilized powder — a freeze-dried white or off-white solid in a sealed vial. To prepare it for use in research, the powder is reconstituted by slowly adding bacteriostatic water (water with a small amount of benzyl alcohol to prevent bacterial growth) directly to the vial. Aim the liquid at the glass wall, not at the powder directly, and gently swirl — never shake vigorously, as this can break down peptide chains. Once mixed, the solution should be clear and colorless. Store unreconstituted vials in a cool, dry place away from light; many researchers keep them refrigerated at 2–8 °C. After reconstitution, keep the vial refrigerated and use within a few weeks for best stability. Always check your specific supplier's certificate of analysis for purity and recommended handling. These are general research-handling guidelines only and do not constitute medical or pharmaceutical advice.

Sources

1. Pralmorelin: GHRP 2, GPA 748, growth hormone-releasing peptide 2, KP-102 D, KP-102 LN, KP-102D, KP-102LN. — Drugs in R&D, 2004. PMID 15230633.
2. Growth hormone releasing peptide-2 (GHRP-2), like ghrelin, increases food intake in healthy men. — The Journal of clinical endocrinology and metabolism, 2005. PMID 15699539.
3. Detection of GHRP-2 and GHRP-6 in urine samples from athletes. — Drug testing and analysis, 2015. PMID 25809000.
4. GHRP-2, a GHS-R agonist, directly acts on myocytes to attenuate the dexamethasone-induced expressions of muscle-specific ubiquitin ligases, Atrogin-1 and MuRF1. — Life sciences, 2008. PMID 18191156.
5. Growth hormone-releasing peptide-2 (GHRP-2) does not act via the human growth hormone-releasing factor receptor in GC cells. — Endocrine, 1998. PMID 9798733.
6. Determination of growth hormone releasing peptides metabolites in human urine after nasal administration of GHRP-1, GHRP-2, GHRP-6, Hexarelin, and Ipamorelin. — Drug testing and analysis, 2015. PMID 25869809.