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Growth Hormone

GHRP-1 Guide & Dosage Chart

A growth-hormone-releasing peptide studied for GH release.

Routesubcutaneous
GHRP-1 — Dosage chart
Every row cited
GoalDoseFrequencyDurationEvidenceSource
Cited dosing data is being compiled for this compound.
For research and educational use only. Not medical advice.

What is GHRP-1?

GHRP-1 — short for Growth Hormone-Releasing Peptide 1 — is a small, fully synthetic peptide made up of seven amino acids (making it a heptapeptide).[6] It does not exist in nature. Scientists designed it specifically to trigger the pituitary gland to release growth hormone (GH). It belongs to a family of lab-made compounds called GHRPs, which also includes the better-known GHRP-2, GHRP-6, and Hexarelin.[2] GHRP-1 is sometimes referred to by its research code name KP 101.[3] It is studied strictly as a research compound and is not approved for human therapeutic use.

How GHRP-1 Works

Think of growth hormone release like a locked door. Your pituitary gland holds the door; it needs the right key to swing open and pour out GH. GHRP-1 acts like one of those keys — it binds to specific receptors on pituitary cells (and possibly in the hypothalamus, the brain region above it) and signals them to release GH.[6]

Here is what makes GHRP-1 interesting: it works through a completely different lock than the body's own natural signal, a hormone called GHRH (Growth Hormone-Releasing Hormone). Lab studies confirmed that blocking the GHRH receptor with a chemical antagonist did not stop GHRP-1 from releasing GH — proof that it uses its own distinct pathway.[3] The receptor it binds to has been cloned by researchers, and it does not look like any other known receptor in the body, which hints that a natural GHRP-like messenger molecule may exist in humans — though scientists have not found it yet.[2]

Calcium is also part of the story. When researchers blocked calcium channels in pituitary cells, GHRP-1's ability to stimulate GH release was completely switched off — showing that calcium flow inside the cell is essential to the process.[3]

What the Research Shows

Early cell studies

In one of the first detailed lab investigations, researchers used sheep pituitary cells in continuous perifusion (a method where fluid flows constantly over the cells) to test GHRP-1 alongside GHRP-6 and natural GHRH. GHRP-1 raised GH release in a dose-dependent way — more peptide, more GH — though it took roughly ten times the dose to reach the same effect as GHRH on those particular cells.[3]

Animal studies

In live lambs, intravenous injections of GHRP-1 did raise blood GH levels, with the highest test dose (6 nmol/kg) producing the clearest response. However, a much smaller dose of GHRH outperformed it in those animals, suggesting GHRP-1 is a weaker stimulant of GH in sheep than in some other species.[4] Researchers noted that animals with a strong reaction to GHRP-1 tended to show a weaker reaction to GHRH, and vice versa — hinting at different intracellular mechanisms at play.[4]

Human pharmacology research

Studies in humans placed GHRP-1 in a trio with GHRP-6 and GHRP-2, all three of which were found to release GH more effectively than GHRH 1-44 NH₂ when given to healthy volunteers. Notably, GHRP-1 was shown to stimulate significant GH release even after oral administration — a property rare among peptides, which usually break down in the gut.[5] Combining a small intravenous dose of GHRP-1 with GHRH produced a synergistic effect — meaning the two together released far more GH than either alone.[5] This synergy has been consistently observed across the GHRP family.[2]

Routes of administration and detection

Anti-doping researchers studied what happens to GHRP-1 after it enters the body. When administered nasally, the parent compound itself was not found in urine at all — it was broken down quickly. However, six metabolites (breakdown products) were identified, with one fragment called GHRP-1 (2-4) free acid detectable in urine for up to 27 hours after dosing.[1] GHRP-1 is listed on the World Anti-Doping Agency (WADA) Prohibited List.[1]

Age and other factors

Research across the GHRP family shows that GH-releasing activity generally peaks around puberty, stays relatively stable through adulthood, and then declines with age — though it remains detectable even in older individuals.[6] The effect does not differ between males and females.[6]

What GHRP-1 Is Being Studied For

  • GH secretion mechanisms — understanding how GH release is triggered independently of GHRH
  • Synergistic GH release — exploring how GHRPs and GHRH interact to amplify output[5]
  • Age-related GH decline — investigating whether GHRPs can restore blunted GH responses[6]
  • Anti-doping science — developing urine tests to detect GHRP use in sport[1]
  • Metabolic and body-composition research — as part of broader GH secretagogue programs[2]

How GHRP-1 Is Dosed in Research

Because dosing depends heavily on the specific research model, administration route, and goals of a given study, there is no single universal protocol for GHRP-1. Published animal research used intravenous bolus doses measured in nanomoles per kilogram of body weight,[4] while human pharmacology work explored intravenous, subcutaneous, intranasal, and oral routes.[5] For a structured overview of the amounts used across studies, please refer to the dosage chart on this page and use the interactive calculator to explore weight-based reference values from the published literature. This page is for research and educational reference only — none of this constitutes medical advice or a prescription.

Mixing and Storing GHRP-1

GHRP-1 is supplied as a lyophilized powder — a freeze-dried solid that must be reconstituted (dissolved) before use in research. The standard solvent is bacteriostatic water (sterile water containing a small amount of benzyl alcohol to prevent bacterial growth). To reconstitute, researchers inject the solvent slowly down the inside wall of the vial — never directly onto the powder — and gently swirl rather than shake, which can damage the peptide structure. Once dissolved, the solution should be stored in a refrigerator (2–8 °C / 36–46 °F) and protected from light. Most reconstituted solutions are considered stable for up to four weeks when refrigerated. Unused dry powder should be kept frozen (around −20 °C) until needed, away from moisture and light. Always label vials with the date of reconstitution.

Sources

  1. 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.
  2. Growth hormone-releasing peptides. — European journal of endocrinology, 1997. PMID 9186261.
  3. Effects in vitro of new growth hormone releasing peptide (GHRP-1) on growth hormone secretion from ovine pituitary cells in primary culture. — Journal of neuroendocrinology, 1994. PMID 8049717.
  4. In vivo effects of the GH-releasing heptapeptide GHRP-1 in lambs. — Reproduction, nutrition, development, 1998. PMID 9698275.
  5. GH releasing peptides--structure and kinetics. — The Journal of pediatric endocrinology, 1993. PMID 8374685.
  6. Growth hormone-releasing peptides and their analogs. — Frontiers in neuroendocrinology, 1998. PMID 9465289.

GHRP-1 FAQ

What is GHRP-1?
GHRP-1 is a synthetic seven-amino-acid peptide (heptapeptide) designed in the laboratory to stimulate the pituitary gland to release growth hormone. It belongs to the GHRP family of research compounds and is sometimes called KP 101.[3] It is not a naturally occurring substance and is not approved for human therapeutic use — it is studied as a research compound only.[6]
How does GHRP-1 work?
GHRP-1 binds to specific receptors on pituitary and hypothalamic cells that are entirely separate from the receptors used by the body's own growth-hormone signal (GHRH).[2] This triggers calcium-dependent signaling inside the cell, causing GH to be released.[3] Because it uses a different receptor, it can work alongside GHRH to produce a synergistic — greater-than-additive — release of GH.[5]
What is GHRP-1 used for in research?
Researchers study GHRP-1 mainly to understand how growth hormone release is regulated, how GHRPs interact synergistically with GHRH, and how GH secretion changes with age.[6] Anti-doping scientists also study it to develop urine tests capable of detecting its metabolites after administration, since it is on the WADA Prohibited List.[1]
How is GHRP-1 dosed in research studies?
Doses vary widely depending on the research model. Animal studies used intravenous bolus doses in the nanomole-per-kilogram range,[4] while human pharmacology research explored intravenous, subcutaneous, intranasal, and oral routes.[5] Refer to the dosage chart on this page for a structured summary and use the calculator for weight-based reference values. This is for research reference only.
How do you reconstitute GHRP-1?
GHRP-1 research vials come as a freeze-dried powder. Researchers dissolve it by slowly injecting bacteriostatic water down the inside wall of the vial and gently swirling — never shaking. The reconstituted solution is then refrigerated at 2–8 °C, protected from light, and typically used within four weeks. Dry powder should be stored frozen at around −20 °C until needed.
Is GHRP-1 considered safe?
GHRP-1 is a research compound, not an approved drug, so comprehensive human safety data are limited. It is listed on the WADA Prohibited List, meaning its use in competitive sport is banned.[1] Like other GHRPs, partial desensitization has been observed with continuous use.[2] No safety conclusions can be drawn from this page. Anyone considering research involving GHRP-1 should follow all applicable institutional and regulatory guidelines.