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What it is
Growth hormone-releasing peptide 2, also called pralmorelin or KP-102, is a synthetic hexapeptide that prompts the pituitary to release growth hormone. It is related to GHRP-6 but is not growth hormone and does not copy the structure of natural GHRH.
GHRP-2 has been studied in human hormone-challenge tests and pediatric growth research. It is approved in Japan as a diagnostic agent for severe growth hormone deficiency, but it has no FDA-approved use in the United States. Research-vial claims about muscle gain, fat loss, recovery, or anti-aging go beyond the clinical evidence.
What people research it for
Produces a measurable growth hormone response
Human studiesSmall human challenge studies found strong, short-lived growth hormone release after GHRP-2. This supports endocrine testing, not claims of improved muscle or recovery.
Has been studied as a pituitary challenge test
Human studiesClinical studies have compared the GHRP-2 test with established stimulation tests for growth hormone and adrenal reserve. Diagnostic use in Japan does not make research vials approved medicines elsewhere.
Showed a modest growth signal in one small early study
Early human dataA 15-child study reported faster average height velocity during intranasal treatment, but it lacked a placebo group and found no significant IGF-1 increase.
Failed to improve growth in a larger controlled trial
Human studiesA 126-child double-blind study found no significant growth or IGF-1 advantage over placebo after 48 weeks despite transient growth hormone release.
How it works
GHRP-2 activates the growth hormone secretagogue receptor, also called the ghrelin receptor, in the hypothalamus and pituitary. That signal can produce a brief growth hormone pulse and may interact with the body's own GHRH signaling.
The effect is not limited to growth hormone. Human studies found smaller increases in prolactin, ACTH, and cortisol. A laboratory rise in one or more hormones does not establish a lasting benefit in growth, body composition, or recovery.
What the research actually shows
A comparative challenge study enrolled six healthy adults aged 22 to 27 and six adults aged 66 to 73. Intravenous GHRP-2 produced a strong growth hormone response in the younger group, greater than the response to GHRH in that experiment. The peptide also increased prolactin, ACTH, and cortisol, showing that its endocrine action was not growth-hormone-specific.
An early uncontrolled study followed 15 short children. Average height velocity rose from 3.7 cm per year at baseline to 6.1 cm per year at six months, while IGF-1 and IGF-binding protein 3 did not change significantly. Only six children continued for 18 to 24 months, so the result was promising but highly uncertain.
A later double-blind study tested intranasal GHRP-2 for 48 weeks in 126 prepubertal children with growth hormone deficiency. Changes in height standard-deviation score were 0.07 with placebo, 0.03 with the lower GHRP-2 amount, and 0.02 with the higher amount. The groups did not differ significantly, and IGF-1 did not improve.
The larger trial is an important negative result. It showed that provoking brief endogenous growth hormone release did not necessarily create a meaningful growth effect. That finding cautions against treating a hormone spike as proof of a practical benefit.
GHRP-2 has also been studied as a challenge test for the hypothalamic-pituitary-adrenal axis. Those studies reinforce that it can stimulate ACTH and cortisol as well as growth hormone, which complicates claims that it acts selectively on one pathway.
No robust randomized trial was found showing that GHRP-2 improves lean mass, athletic performance, injury healing, fat loss, or healthy aging. The available human literature centers on hormone responses, diagnostic testing, and pediatric growth, with mixed treatment results.
Handling & storage
Storage at a glance
Vendor consensus- Lyophilized
- below -18 to -20°C
- about 3 weeks at room temperature according to the checked technical sheets
- Keep sealed and desiccated.
- Reconstituted
- 2 to 8°C
- Use within 2 to 7 days where the ProSpec product instructions apply
- No universal formulation-specific expiry was found.
- Light
- Protect from moisture and unnecessary light exposure.
- Room temperature
- Checked technical sheets describe about 3 weeks for sealed dry material.
- Reconstitution
- product-specified sterile diluent
- Follow the exact product instructions and avoid repeated freezing and thawing.
Basis: Vendor consensus. Sources: ProSpec GHRP-2 technical product page, Genaxxon GHRP-2 technical data sheet
Two checked technical suppliers describe GHRP-2 as a lyophilized powder and agree on dry storage below about -18 to -20°C. Both state that sealed dry material can tolerate roughly three weeks at room temperature, which is a handling allowance rather than a universal shelf life.
The sources agree that reconstituted material should be refrigerated, with ProSpec giving 4°C for 2 to 7 days and Genaxxon listing 2 to 8°C without a shared use-by period. These are product-specific technical instructions, not a published finished-vial stability study. Protect the material from moisture and repeated freezing and thawing.
Safety & cautions
Human challenge studies show that GHRP-2 can raise prolactin, ACTH, and cortisol along with growth hormone. Possible concerns therefore include flushing, appetite changes, fluid retention, glucose disruption, and effects linked to excessive growth hormone or IGF-1 signaling. Short studies cannot define uncommon or long-term harms.
GHRP-2 is not FDA approved. Research products can vary in identity, purity, fill amount, sterility, and endotoxin burden. Safety has not been established for pregnancy, children outside supervised research, cancer, diabetes, pituitary or adrenal disorders, or long-term wellness use.
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Frequently asked questions
Is GHRP-2 FDA approved?
No. GHRP-2 has no FDA-approved medical use in the United States. It has diagnostic use in Japan, which does not make research vials approved medicines.
Is GHRP-2 the same as growth hormone?
No. It activates the ghrelin receptor and prompts the pituitary to release endogenous growth hormone. It does not supply growth hormone directly.
Does GHRP-2 build muscle or reduce fat?
Reliable randomized evidence for those outcomes was not found. Human studies mainly measured short-term hormone responses or pediatric growth.
Did GHRP-2 help children grow?
One small uncontrolled study reported faster growth, but a larger 126-child double-blind trial found no significant advantage over placebo after 48 weeks.
Does GHRP-2 affect only growth hormone?
No. Human challenge studies also found increases in prolactin, ACTH, and cortisol.
How should laboratory GHRP-2 be stored?
Checked technical sheets agree on frozen, dry storage below about -18 to -20°C and refrigeration after reconstitution. The shortest product-specific mixed window found was 2 to 7 days.
Sources
- Arvat and colleagues, GHRP-2 and hexarelin hormone responses
- Pihoker and colleagues, intranasal GHRP-2 in short children
- Tanaka and colleagues, placebo-controlled pediatric trial
- GHRP-2 test compared with insulin tolerance testing
- GHRP-2, CRH, and ACTH responses in pituitary disorders
- ProSpec GHRP-2 technical product page
- Genaxxon GHRP-2 technical data sheet
Last reviewed September 17, 2026. This guide is educational and research-focused, not medical advice. GHRP-2 products referenced on PeptidePub are sold by third parties as materials for laboratory research use only, not for human or animal consumption.
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