Growth Hormone Axis · Dosing reference

GHRP-2 dosage

What the human evidence does and does not show, how long studies ran, and the arithmetic for working with vials.

Approved outside the USBLimited human dataNone established

Full research page Cycle-length evidence Compare Prefer Amiravo on Google

Regulatory status: Approved outside the US
Human amounts: None established in humans
Route studied: —
Frequency: Not established
Half-life: In a Japanese package insert, the terminal elimination half-life after intravenous administration to healthy adult men was reported as roughly 0.4 to 0.7 hours ^5.
Evidence grade: Grade B · Limited human data
Vial sizes on the market: 5 mg · 10 mg
Other forms seen: —

What GHRP-2 is

GHRP-2 (pralmorelin) is a synthetic hexapeptide that acts on the ghrelin/growth hormone secretagogue receptor system. Its best-documented human use is as a single-administration diagnostic test for growth hormone deficiency in Japan. It is not approved by the FDA and is prohibited in sport.

Synthetic growth hormone secretagogues were found to act on a G protein-coupled receptor cloned from swine and human pituitary and hypothalamus ^12. The endogenous ligand for that receptor was later purified from rat stomach and named ghrelin, a 28-amino-acid acylated peptide that releases GH in vivo and in vitro ^13. GHRP-2 has been described as a synthetic agonist of ghrelin that binds the GH secretagogue… How it works →

Key evidence

Chihara et al. (KP-102 Study Group), Eur J Endocrinol · 2007 · Humans (77 healthy adults, 58 adults with GH deficiency)
Peak GH after GHRP-2 was significantly lower in patients than in healthy subjects, with no difference between hypothalamic and pituitary disease, and the test showed favourable reproducibility. ³
Laferrere et al., J Clin Endocrinol Metab · 2005 · Humans (7 lean healthy men)
Participants ate about 36% more during GHRP-2 infusion than during saline, every participant increased intake, and serum GH rose. ⁶
Laferrere et al., Obesity · 2006 · Humans (10 lean and 9 obese healthy adults)
Food intake rose in a dose-dependent manner, obesity status did not change the response, and serum GH increased dose dependently. ⁷

All studies on the research page

What the human evidence shows

No approved or established human dose

We searched PubMed and ClinicalTrials.gov and found no human studies that administered GHRP-2. The research described on its page is from cells or animals, and animal amounts do not translate to people.

How long did human studies run?

No human study durations are recorded for GHRP-2.

Cycle-length evidence for GHRP-2

Side effects reported in studies

Sensation of warmth
16.0% (listed in the 5% or higher category) · Clinical experience summarized in the Japanese package insert for the diagnostic product ⁵
Other listed reactions: hypotension, ALT elevation, gastrointestinal symptoms (borborygmi, nausea, abdominal discomfort or pain, bloating), somnolence, dizziness, rhinorrhea, leukocytosis, sweating, thirst, hunger, malaise, bitter taste, back pain, headache, facial flushing
Listed in lower-frequency or frequency-unknown categories; per-event rates are not tabulated here · Japanese package insert, diagnostic use ⁵
Increased food intake (pharmacodynamic effect)
About 36% more intake than saline in 7 lean men; dose-dependent in a 19-participant study · Healthy lean and obese volunteers receiving infusions ⁶

Full adverse-event data

GHRP-2 draw calculator

Pick the vial strength and the water added, enter an amount, and see the concentration, the units to draw and how many draws the vial holds. Arithmetic only.

1 · Vial strength

sizes on the market

2 · Water added

3 · Amount per draw

4 · Syringe

Your mix

10 mg + 2 mL water = 5 mg/mL

10 units holds 0.5 mg (500 mcg)

Draw toEnter an amount in step 3

U-100 syringe · 100 units = 1 mL

Computed from your inputs. Not a dose or a recommendation.

Compare water volumes for this vialShow

More water = lower concentration = a larger, easier-to-measure draw. Tap a row to use it.

Water	mg/mL	Draw
0.5 mL	20	—
1 mL	10	—
1.5 mL	6.667	—
2 mL	5	—
2.5 mL	4	—
3 mL	3.333	—
5 mL	2	—

Supplies and handling

Lyophilized vial
Sealed vial with the freeze-dried cake. Check the label, lot and the certificate of analysis before opening.
Sterile diluent
The diluent named on the product documentation. Bacteriostatic water contains benzyl alcohol; sterile water does not.
Graduated syringes
Sized to the volume being measured. U-100 insulin syringes are graduated in units where 100 units = 1 mL.
Alcohol prep pads
For wiping vial stoppers before each puncture.
Nitrile gloves
Clean gloves for aseptic handling.
Sharps container
Puncture-resistant container for used needles.

Step-by-step reconstitution guide Storage and transport accessories

Storage

General research-context handling for lyophilized peptides: keep cold, dry and protected from light, avoid repeated freeze-thaw of any solution, and follow the supplier's documentation. Published stability data for reconstituted material are limited.

Lyophilized (unmixed) vials: typically stored cold and dry, away from light, as the documentation directs. Many are stable longer frozen.
Reconstituted vials: typically refrigerated (about 2–8 °C), protected from light and not frozen.
Bacteriostatic water contains benzyl alcohol, which inhibits bacterial growth in multi-use vials; sterile water has no preservative.

Handling mistakes and troubleshooting

Added the wrong volume of diluent: The concentration changes, not the amount of compound in the vial. Recalculate with the volume actually added and relabel the vial.
Shook the vial and it foamed: Let it settle in the refrigerator. Foam is a sign of agitation; some peptides aggregate when shaken. Note it on the label.
The solution is cloudy or has particles: Do not use it. Cloudiness can indicate incomplete dissolution, contamination or degradation. Record the lot and contact the supplier with the certificate of analysis.
The powder cake looks melted or shrunken before reconstitution: This can indicate the vial was exposed to heat or moisture. Record the lot and condition on arrival.
Liquid sprayed back when the needle was removed: Pressure built up in the vial. Withdraw a small volume of air while adding diluent to keep pressure neutral.

Regulatory status

Status: Not approved by the FDA for any use ^10. In Japan, a single-dose pralmorelin injection (GHRP Kaken 100, Kaken Pharmaceutical) is a prescription diagnostic agent for growth hormone secretion failure, with a listed sales start of February 2005 ^5.
United States (FDA): GHRP-2 is not approved by the FDA for any use ^10. FDA's categorization of nominated 503A bulk drug substances (updated May 14, 2026) lists GHRP-2 in Category 3, bulk drug substances nominated without adequate support ^10. A drug profile reported that a US phase II program for GH deficiency with Wyeth appeared to have been discontinued ^1.
Sport (WADA): The WADA 2026 Prohibited List names GHRP-2 (pralmorelin) under S2.2.4 (growth hormone releasing factors, including GH-releasing peptides); S2 substances are prohibited at all times, in and out of competition, and are non-Specified Substances ^11.

Status varies by country and changes over time. How we describe regulatory status.

GHRP-2 compared with related compounds

Compound	Status	Evidence	Human amounts	Half-life
GHRP-2	Approved outside the US	B	None established	In a Japanese package insert, the termin
GHRP-6	Not approved — research use only	B	None established	—
Ipamorelin	Not approved — research use only	B	None established	Terminal half-life of about 2 hours in h
Kisspeptin-10	Not approved — research use only	B	None established	—
CJC-1295 (no DAC)	Not approved — research use only	C	None established	No half-life data specific to the no-DAC
CJC-1295 (with DAC)	Not approved — research use only	B	None established	Estimated half-life of 5.8 to 8.1 days a

Frequently asked questions

What doses of GHRP-2 have been studied in humans?

None that establish an amount. GHRP-2 is not approved anywhere and we found no human studies that administered it. Amiravo does not publish community or vendor figures.

Is there an established GHRP-2 cycle length?

No. We found no human studies that report treatment duration for GHRP-2.

How much bacteriostatic water should be added to a GHRP-2 vial?

There is no compound-specific volume. The diluent volume only sets the concentration: concentration = mass in the vial ÷ volume added (for example, 10 mg in 2 mL gives 5 mg/mL). The calculator on this page shows the arithmetic for any combination.

How many units is a given amount on an insulin syringe?

On a U-100 syringe, 100 units = 1 mL. Units for an amount = amount ÷ (concentration per unit). The calculator converts any amount you enter at the concentration you choose; a unit is a volume mark, not an amount of compound.

What is the half-life of GHRP-2?

In a Japanese package insert, the terminal elimination half-life after intravenous administration to healthy adult men was reported as roughly 0.4 to 0.7 hours ^5.

Is GHRP-2 FDA-approved?

Approved outside the US. Not approved by the FDA for any use ^10. In Japan, a single-dose pralmorelin injection (GHRP Kaken 100, Kaken Pharmaceutical) is a prescription diagnostic agent for growth hormone secretion failure, with a listed sales start of February 2005 ^5.

References

Pralmorelin: GHRP 2, GPA 748, growth hormone-releasing peptide 2, KP-102 D, KP-102 LN, KP-102D, KP-102LN Drugs R D. 2004
Pharmacological characteristics of KP-102 (GHRP-2), a potent growth hormone-releasing peptide Arzneimittelforschung. 2004
A simple diagnostic test using GH-releasing peptide-2 in adult GH deficiency Eur J Endocrinol. 2007
Adult growth hormone deficiency: current concepts Neurol Med Chir (Tokyo). 2014
Package insert: GHRP Kaken 100 Injection (pralmorelin hydrochloride), 3rd revision PMDA (Japan) prescription drug information. 2025
Growth hormone releasing peptide-2 (GHRP-2), like ghrelin, increases food intake in healthy men J Clin Endocrinol Metab. 2005
Obese subjects respond to the stimulatory effect of the ghrelin agonist growth hormone-releasing peptide-2 on food intake Obesity (Silver Spring). 2006
Robust growth hormone responses to GH-releasing peptide 2 in adolescents J Pediatr Endocrinol Metab. 2024
Assessment of anterior pituitary reserve capacity based on growth hormone response to growth hormone-releasing peptide-2 test in the elderly Growth Horm IGF Res. 2023
Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the FD&C Act (categories 1, 2 and 3; updated May 14, 2026) FDA. 2026
International Standard: Prohibited List 2026 (S0 Non-approved substances; S2 Peptide hormones, growth factors, related substances and mimetics) World Anti-Doping Agency. 2026
A receptor in pituitary and hypothalamus that functions in growth hormone release Science. 1996
Ghrelin is a growth-hormone-releasing acylated peptide from stomach Nature. 1999

Last reviewed October 22, 2026 by the Amiravo editorial team. Editorial policy · Report an error