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Lexicon
Hormones & growth

GHRP-2

A potent ghrelin mimetic that triggers a strong GH pulse, stronger than GHRP-6, but with some appetite boost.

2 min read 14 sources

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GHRP-2 vial with white powder and the black TPD label on a white podium, next to a large blue 3D molecule model in a bright lab
Compound approved · in Japan as a growth hormone test agent

Summary

At a glance

Sources checked on 26 Oct 2026

More food eaten
+35.9 %

7 healthy men at a buffet, GHRP-2 versus saline, every one ate more1

Growth hormone in blood
13.5 -fold

area under the curve over 4 hours versus saline, calculated from the means1

GH peak in healthy adults
84.6 ng/ml

after one test dose into a vein, 1.36 ng/ml in patients with GH deficiency2

Children with more appetite
70 %

7 of 10 children with GH deficiency in the first 6 months, GHRP-2 as a tablet4

Phase 3 in registries
2 trials

two running trials of the GHRP-2 test in Japan (jRCT), none on ClinicalTrials.gov, as of 26 Oct 202612

  • GHRP-2 (pralmorelin) is a synthetic peptide that acts on the ghrelin receptor like the stomach hormone ghrelin. The pituitary gland then releases growth hormone.781
  • In Japan GHRP-2 is approved as a test agent: a single dose shows whether the pituitary gland can make enough growth hormone.562
  • In 7 healthy men GHRP-2 infused under the skin raised the amount eaten at a buffet by 35.9 percent. Growth hormone rose markedly at the same time.1
  • In children with GH deficiency night-time growth hormone rose with the dose, but IGF-1 did not. The effect of each dose was short-lived.3
  • Japanese registries list trials of the GHRP-2 test, ClinicalTrials.gov lists none (as of October 2026). There is no approval for performance or physique goals. Everything here is the state of research, not a recommendation.121310
Profile

Updated May 2026

Class
GH secretagogue

ghrelin mimetic

Use
Subcutaneous

in mcg

Half-life
short
WADA
Banned

peptide hormones

Sizes
5 to 15 mg

3 sizes in the shop

Contents 16 sections
  1. At a glance
  2. What is GHRP-2?
  3. How it works
  4. What you need
  5. Reconstitution
  6. Dosing
  7. Injection
  8. What the research shows
  9. Research status
  10. Side effects
  11. Practice
  12. Storage
  13. Related compounds
  14. FAQ
  15. Glossary
  16. Sources

What is GHRP-2?

GHRP-2 (also pralmorelin) is a synthetic GH secretagogue from Cyril Bowers' research series. Like ghrelin it activates the GH secretagogue receptor and triggers a GH pulse. Compared with GHRP-6 it acts somewhat more strongly on GH release and drives appetite less, though the hunger effect is not gone.

Comparison

Three points on the growth hormone axis

Where the peptides from the lexicon act on the growth hormone axis. Tap a card to open its entry.

Ghrelin mimetic, injection GHRP-2 GHSR GHRH-R GH-R 1 of 3 targets
Ghrelin mimetic, injection GHRP-6 GHSR GHRH-R GH-R 1 of 3 targets Ghrelin mimetic, injection Ipamorelin GHSR GHRH-R GH-R 1 of 3 targets Ghrelin agonist, tablet MK-677 (Ibutamoren) GHSR GHRH-R GH-R 1 of 3 targets GHRH analogue CJC-1295 without DAC GHSR GHRH-R GH-R 1 of 3 targets Growth hormone itself HGH 191AA (Somatropin) GHSR GHRH-R GH-R 1 of 3 targets

Simplified: GHRP-2 and ghrelin mimetics act on the ghrelin receptor, GHRH analogues on the GHRH receptor. Both routes release the body's own growth hormone. 7

How it works

GHRP-2 binds the ghrelin receptor (GHS-R1a) and through it triggers a pulsatile GH release. Combined with a GHRH analog like CJC-1295 without DAC, two signaling routes add up and the GH pulse is markedly higher.

The effect is saturable: above a certain dose (roughly 200 to 300mcg per shot) GH output barely rises further, higher doses mainly bring more side effects.

Where it acts

Where GHRP-2 acted in studies

Tap a point or a card. Colour = ghrelin receptor, grey = observed in studies.

  1. Pituitary and hypothalamus

    Growth hormone peak within 60 minutes after the test dose2

    GHSR
  2. Stomach

    Makes ghrelin, the body's own hormone at the same receptor8

    Observed in trials
  3. Growth

    Higher growth velocity in 6 children with GH deficiency during treatment3

    Observed in trials

Targets in the ChEMBL database14

Compound CHEMBL106593: one recorded mechanism, Agonist according to studies, no mechanism recorded in ChEMBL.

Ghrelin receptor (GHSR)
Gene
GHSR
UniProt
Q92847
ChEMBL
CHEMBL4616
Action
Agonist according to studies, no mechanism recorded in ChEMBL
Blue 3D molecules dock onto glass-like receptors on a light blue cell membrane
Symbolic image.

What you need

Supplies

2 things, numbered as in the picture

Tick off what you already have. Vial and BAC water are our real shop photos at the same size.

GHRP-2 vial and bacteriostatic water at the same size with the black TPD label, next to two U-100 insulin syringes, two alcohol swabs and a sharps container with a blue lid

  1. GHRP-2 vial

    The GHRP-2 vial (lyophilized powder).

    In the shop

  2. BAC water, syringes and swabs

    Bacteriostatic water, U-100 insulin syringes, alcohol swabs.

    In the shop Amazon (opens a new tab)

As an Amazon associate we earn from qualifying purchases. Links open Amazon - no extra cost for you.

Reconstitution

Use the peptide calculator. A 5mg vial with 2ml water gives 2500mcg per ml, 100mcg is then 4 units on the U-100 syringe. Just add the water to the vial and let it dissolve.

Step by step

Dissolving the powder

Four steps, the same for every vial size.

  1. 1Wipe the cap

    Clean the rubber stopper with an alcohol swab.

  2. 2Add BAC water

    Just add it, it does not matter if it hits the powder directly.

  3. 3Swirl or shake

    Until everything has dissolved, both are fine.

  4. 4Draw up

    With the U-100 insulin syringe.

Less water higher concentration fewer units on the syringe Example: 5 mg + 2 ml = 2.5 mg/ml

Dosing

Dosing

Dosing, titration and syringe

Loading the dosing information …

  • Getting started and stepping up, drawn as a staircase
  • Units on the U-100 syringe for every step
  • How long one vial lasts

Injection

The injection is subcutaneous, into the fat layer under the skin. Common spots are the abdomen (keep about two finger-widths clear of the navel), the front and the inner side of the thigh, or the back of the upper arm.

The short version:

Injection

Where and at what angle

Pick a spot or switch the angle. Subcutaneous means: into the fat layer, not the muscle.

Rotate the spot each time, never the same one twice in a row.

90°More fat under the skin

Rule of thumb: where there is more fat under the skin, insert straight at 90 degrees. In lean people with little fat, 45 degrees, so the needle stays in the fat layer. Simplified diagram.

  1. Clean the spot with an alcohol swab and let it dry

  2. Pinch up a small fold of skin

  3. Insert the needle: at 90 degrees where there is more fat under the skin, at 45 degrees in lean people with little fat

  4. Inject slowly, wait a moment, then withdraw

  5. Put the needle straight into the sharps container

Rotate the site each time so the tissue does not get irritated. Never the same spot twice in a row.

Inject fasted with a gap to meals.

What the research shows

GHRP-2 is well studied: it raises GH dose-dependently and was even used in GH-deficient children. A study in healthy men (Laferrère, 2005) showed that GHRP-2, like ghrelin, increases food intake, the appetite effect to be aware of.

Study results

What the trials measured

Interactive: switch tabs, tap points, show or hide arms. Arms are named relative to each other, no dosing advice.

Amount eaten at a buffet1

Energy per kg body weight, 7 healthy men, each once with GHRP-2 and once with saline

Meal after the infusion1 Infusion under the skin over 4.5 hours
Saline (comparison) 101.3 kJ/kg
GHRP-2 136.0 kJ/kg

Every participant ate more with GHRP-2, the composition of the meal stayed the same. Given as an infusion, not as a single injection.

Highest growth hormone level after the test2

Mean after one test dose into a vein, 77 healthy adults and 58 patients

GH peak within 2 hours2 Patients with severe GH deficiency according to the insulin tolerance test
Healthy adults 84.60 ng/ml
Patients with GH deficiency 1.36 ng/ml

Cut-off for severe GH deficiency: 15 ng/ml, 9 ng/ml with the newer WHO standard. The peak came within 60 minutes in everyone.

Bright desk by the window with a plant, a notepad and a glass anatomical model on a marble stand
Symbolic image.

Research status

Where the research stands

ClinicalTrials.gov lists no trial of GHRP-2, also not under pralmorelin or KP-102. The Japanese registries jRCT and UMIN-CTR list trials of the GHRP-2 test, its use as an approved test agent. On top come the approval study for the test and a phase 1 trial in children, both without a registry number. As of 26 Oct 2026. 1312

  1. Preclinical Animal studies on ghrelin receptor agonists
  2. Phase 1 1 trial, 1 completed
  3. Phase 2 no registered trial
  4. Phase 3 2 trials, 0 completed
  5. Approval in Japan as a growth hormone test agent
55 participants in phase 3 Planned figures for running trials Approved in Japan as a test agent for diagnosing growth hormone deficiency (according to a review). ChEMBL lists pralmorelin with phase 2 as the highest phase. No approval for performance or physique goals.5
Show all 5 trials on a timelineHide timeline 3 completed 2 running 1 with results
Phase 3
Without phase

Bar: start to primary endpoint (planned for running trials), for published trials without a stated period the year of publication. Green = completed, blue = progress until 26 Oct 2026. Phase 1: 1 trial on safety and pharmacokinetics, not shown as bars.

Side effects

  • Increased appetite (via the ghrelin signal), weaker than GHRP-6.
  • Water retention, tingling, briefly raised cortisol and prolactin at higher doses.
  • Local reactions at the injection site.

Tolerability

Tolerability in small studies

Two small studies in children with GH deficiency.

70 of 100 GHRP-2
Event GHRP-2
More appetite4 70%
Side effects or organ damage3 0%

Zero only means: nothing observed in six children. Body mass index did not rise significantly despite the appetite. Reviews list higher prolactin and cortisol, appetite changes, fluid retention, muscle and joint pain as well as blood sugar disturbances for GH secretagogues.3410

Practice

  1. Strong as a GHRP partner to a GHRH analog.

  2. Stay low, the effect is saturated above 200 to 300mcg.

  3. Banned in official competition.

Bright table with a glass of water, a bowl of rice with vegetables and two light blue dumbbells

Storage

Before mixing the powder is robust, normal room temperature (around 20 to 25 degrees) is fine, ideally kept in the dark. After mixing, keep in the fridge (2 to 8 degrees), do not freeze. It stays good there for at least 4 to 6 months with barely any loss of potency, in practice considerably longer. Swirl or shake to mix, both are fine.

Shelf life

How long it keeps

Undissolved (powder) Room temperature, around 20 to 25 degrees, dark

Robust, no fridge needed. Best kept in the dark.

Dissolved (mixed) Fridge, 2 to 8 degrees, do not freeze

At least 4 to 6 months with barely any loss of potency.

  • Keep it dark
  • Dissolved: 2 to 8 degrees
  • Note the mixing date on the vial
Nine vials with white powder and blue caps in the door shelf of a bright fridge
Powder dark at room temperature, once dissolved into the fridge (2 to 8 degrees), stable there for at least 4 to 6 months. Symbolic image.

Related

Related compounds

Same receptors or a different path: all in the TPD lexicon.

GHRP-2
GHRP-6 First peptide of this group, same receptor Hexarelin Another GH secretagogue Ipamorelin Ghrelin mimetic MK-677 (Ibutamoren) Ghrelin agonist as a tablet CJC-1295 without DAC Different path: GHRH analogue, often combined with a GHRP Sermorelin Different path: GHRH analogue Tesamorelin Different path: GHRH analogue

FAQ

Common questions about GHRP-2

Short answers, each backed by the sources below.

Is GHRP-2 approved?

Only in Japan and there as a test agent: with one dose doctors check whether the pituitary gland makes enough growth hormone. ChEMBL lists pralmorelin with phase 2 as the highest phase, Japanese registries list trials of the test. There is no approval for muscle building, performance or anti-ageing.56141210

How does the GHRP-2 test work?

After one dose into a vein, blood is drawn for two hours. In 77 healthy adults the peak averaged 84.6 ng/ml, in 58 patients with severe GH deficiency 1.36 ng/ml. Below 15 ng/ml (9 ng/ml with the newer WHO standard) this points to severe deficiency. In Japan the test is seen as a convenient and safe alternative to the insulin tolerance test.26

Why does GHRP-2 cause hunger?

GHRP-2 mimics ghrelin, a hormone from the stomach that stimulates appetite as well as growth hormone. In 7 healthy men food intake rose by 35.9 percent. In children with GH deficiency 7 of 10 reported more appetite in the first months, but body mass index did not rise significantly.814

Does GHRP-2 help growth?

In 6 children with GH deficiency night-time growth hormone rose with the dose and they grew faster during treatment. IGF-1 and IGFBP-3 did not rise, however. The effect of each dose was short. The authors concluded that longer-acting forms would be needed.3

How does GHRP-2 differ from GHRP-6?

Both act on the ghrelin receptor. GHRP-6 was described in 1984 as the first peptide of this kind, GHRP-2 came later and became a test agent in Japan. We did not find a direct human comparison of the two in the sources we checked.95

Which side effects are known?

In the study with 6 children over 8 months no side effects or organ damage were observed. The appetite effect is known. Reviews of GH secretagogues also list higher prolactin and cortisol, fluid retention, muscle and joint pain, blood sugar disturbances and injection-site reactions.3410

Glossary

Terms explained briefly

Dotted words in the text open these explanations directly.

GH secretagogue
A substance that triggers growth hormone release instead of replacing it.
Ghrelin
Hormone from the stomach. It stimulates growth hormone release and appetite.
Ghrelin receptor (GHS-R1a)
Docking site in the pituitary and hypothalamus where ghrelin and the GHRPs act. Discovered in 1996.
GHRH
Growth hormone-releasing hormone from the hypothalamus. It acts through its own receptor.
Growth hormone (GH)
Hormone of the pituitary gland, released in pulses, that controls growth and metabolism.
IGF-1
Growth factor made mainly by the liver in response to growth hormone. Used as a measure of longer-term GH action.
Insulin tolerance test
Standard test for GH deficiency in which insulin causes low blood sugar. Too risky for some patients.
Lyophilisate
Freeze-dried powder. Without water a peptide keeps much longer.
Pituitary gland
Small gland below the brain that releases many hormones, including growth hormone.
Subcutaneous
Into the fat layer just under the skin.

Evidence

Sources

Show all 14 sourcesHide sources 11 Studies2 Trial registry1 Database checked 26 Oct 2026

Studies

  1. GHRP-2, like ghrelin, increases food intake in healthy men

    Laferrère et al., Journal of Clinical Endocrinology and Metabolism, 2005

    DOI 10.1210/jc.2004-1719 PMID 15699539
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  2. Simple test for adult GH deficiency using GHRP-2

    Chihara et al., European Journal of Endocrinology, 2007

    DOI 10.1530/EJE-07-0066 PMID 17609397
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  3. Eight months of GHRP-2 in children with GH deficiency

    Mericq et al., Journal of Clinical Endocrinology and Metabolism, 1998

    DOI 10.1210/jcem.83.7.4969 PMID 9661608
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  4. Appetite and weight on oral GHRP-2 in children

    Mericq et al., Journal of Pediatric Endocrinology and Metabolism, 2003

    DOI 10.1515/jpem.2003.16.7.981 PMID 14513874
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  5. Review of ghrelin receptor ligands in clinical trials

    Vodnik et al., Hormone and Metabolic Research, 2016 (online 2015)

    DOI 10.1055/s-0035-1564149 PMID 26551992
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  6. Review of adult GH deficiency, GHRP-2 test in Japan

    Fukuda et al., Neurologia medico-chirurgica, 2014

    DOI 10.2176/nmc.ra.2014-0088 PMID 25070016
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  7. Discovery of the receptor of GH secretagogues

    Howard et al., Science, 1996

    DOI 10.1126/science.273.5277.974 PMID 8688086
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  8. Discovery of ghrelin from the stomach

    Kojima et al., Nature, 1999

    DOI 10.1038/45230 PMID 10604470
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  9. First synthetic GH-releasing hexapeptide (GHRP-6)

    Bowers et al., Endocrinology, 1984

    DOI 10.1210/endo-114-5-1537 PMID 6714155
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  10. Review of performance-enhancing peptides on the GH axis

    Dominikowski et al., Frontiers in Endocrinology, 2026

    DOI 10.3389/fendo.2026.1822475 PMID 42395176
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  11. Phase 1 study of GHRP-2 kinetics and effect in children

    Pihoker et al., Journal of Clinical Endocrinology and Metabolism, 1998

    DOI 10.1210/jcem.83.4.4744 PMID 9543135
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed

Trial registry

  1. Search on the WHO portal ICTRP (all partner registries, GHRP-2, pralmorelin, KP-102)

    WHO International Clinical Trials Registry Platform, Suche vom 26.10.2026; Einträge in jRCT und UMIN-CTR nachgelesen

    Checked 26 Oct 2026 via WHO ICTRP, jRCT, UMIN-CTR
  2. Search on ClinicalTrials.gov (no trial of GHRP-2)

    ClinicalTrials.gov, U.S. National Library of Medicine

    Checked 26 Oct 2026 via ClinicalTrials.gov API v2

Database

  1. Pralmorelin (GHRP-2) in ChEMBL

    ChEMBL, EMBL-EBI (CHEMBL106593)

    Checked 26 Oct 2026 via ChEMBL

In the shop

GHRP-2 in the catalog

Sizes, prices and shipping times are on the product page.

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