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GHRP-2

From PeptidePlaza, the free peptide reference · Entry #017 · Anti-Aging · Hand-curated entry · Editorial standards

Research warning. For educational reference only. Cortisol and prolactin elevation, while less than Hexarelin/GHRP-6, may still confound research results requiring isolated GH evaluation.

GHRP-2 (also known as KP-102, Pralmorelin) is a anti-aging research peptide. A second-generation synthetic hexapeptide GHRP and potent GHSR-1a agonist. More selective than GHRP-6 with less ghrelin-like appetite stimulation, making it widely used in GH axis research protocols.

GHRP-2 (D-Ala-D-β-Nal-Ala-Trp-D-Phe-Lys-NH₂) is a second-generation synthetic hexapeptide growth hormone secretagogue with higher GH-releasing potency than GHRP-6 and less appetite stimulation due to reduced ghrelin-receptor side activity. It is one of the most studied GHRPs with extensive human pharmacology data. Like GHRP-6, it elevates cortisol and prolactin, but to a lesser degree. Research has also examined GHRP-2 in the context of GH deficiency diagnosis (as a provocation test) and muscle protein synthesis.

1 Mechanism of action

Selective GHSR-1a agonism in pituitary and hypothalamus. Stimulates GH release in a pulsatile manner; also mildly elevates cortisol and prolactin. Synergistic with GHRH analogs (CJC-1295, Tesamorelin).

Primary targets: GHSR-1a

2 Reported effects

Effects below are those reported in the published literature cited on this page. They are not claims of clinical benefit and not medical advice.

2.1 Reported benefits

  • Potent GH stimulation (3–5x GHRP-6 at equivalent doses)
  • Clinically validated diagnostic tool for GH deficiency
  • Less appetite stimulation than GHRP-6

2.2 Side effects

  • Mild cortisol and prolactin elevation
  • Increased appetite (less than GHRP-6)
  • Headache and flushing in some protocols

3 Chemical and physical properties

CAS number158861-67-7
Molar mass817.95 g/mol
Purity (typical)>99.2%
Half-life~1 hour
Storage−20 °C, lyophilised powder, desiccated
SolubilitySterile water / bacteriostatic water
Receptors / targetsGHSR-1a

3.1 Amino acid sequence

D-Ala-D-β-Nal-Ala-Trp-D-Phe-Lys-NH₂

4 Research dosages

100–300 μg SC 2–3x daily; 1 μg/kg for GH deficiency testing.

Dosages are reported from published protocols for reference only. Research chemicals are not for human consumption.

5 Research studies (8)

  1. Growth Hormone-Releasing Effect of GHRP-2 in Humans
    Journal of Clinical Endocrinology & Metabolism (1997) · RCT · N=12
    Dose-response characterization of GHRP-2 in healthy adults; demonstrated potent GH secretion with modest cortisol and prolactin co-elevation.
    Key finding: GHRP-2 produced 3–5x greater GH peak than GHRP-6 at equivalent doses with less appetite stimulation.
  2. GHRP-2 as a Diagnostic Test for GH Deficiency
    European Journal of Endocrinology (2010) · RCT · N=142
    Validated GHRP-2 stimulation test as a reliable alternative to insulin tolerance test for GH deficiency diagnosis in adults.
    Key finding: GHRP-2 stimulation test demonstrated 92% sensitivity and 88% specificity for adult GH deficiency diagnosis.
  3. Growth Hormone-Releasing Peptide 2 May Be Associated With Decreased M1 Macrophage Production and Increased Histologic and Biomechanical Tendon-Bone Healing Properties in a Rat Rotator Cuff Tear Model
    Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association (2025) · Preclinical
    GHRP-2 may be associated with decreased M1 macrophage production and increased histologic and biomechanical tendon-bone healing properties in a rat RCT model.
  4. Assessment of anterior pituitary reserve capacity based on growth hormone response to growth hormone-releasing peptide-2 test in the elderly
    Growth hormone & IGF research : official journal of the Growth Hormone Research Society and the International IGF Research Society (2023) · Preclinical
    The present study indicated that adrenocortical function was significantly correlated with GH response to the GHRP-2 test in elderly patients before pituitary surgery.
  5. Clinical Usefulness of the Growth Hormone-Releasing Peptide-2 Test for Hypothalamic-Pituitary Disorder
    Journal of the Endocrine Society (2022) · Preclinical · n=36
    We recommend measuring ACTH as well as GH during the GHRP2 test to avoid overlooking or delaying diagnosis of secondary AI that frequently accompanies GHD.
  6. On the road of dried blood spot sampling for antidoping tests: Detection of GHRP-2 abuse
    Drug testing and analysis (2021) · Preclinical
    In summary, this study provides specific evidence supporting DBS usefulness to detect GHRP-2, and potentially other GHRPs family members, for antidoping tests.
  7. Identification of a novel growth hormone releasing peptide (a glycine analogue of GHRP-2) in a seized injection vial
    Drug testing and analysis (2019) · Review
    The results of this study may indicate a new approach to circumvent a detection of doping practices.
  8. Evaluation of growth hormone-releasing peptide-2 for diagnosis of thyrotropin-producing pituitary adenomas
    Endocrine journal (2018) · Preclinical · n=5
    In addition to TRH test, the GHRP-2 test as a potential diagnostic tool for TSH-producing pituitary adenomas.

6 Safety and risk profile

6.1 Regulatory status

GHRP-2 is currently classified as Investigational. It has no approved human indication in the United States; availability elsewhere does not imply demonstrated safety or efficacy.

Safety score: 48/100 — moderate concern. Derived from clinical data volume, known risks and regulatory status.

6.2 Contraindications

Conditions and populations in which use is contraindicated:

  • Active malignancy (IGF-1 concern)
  • Uncontrolled diabetes
  • Hyperprolactinemia
  • Pregnancy

6.3 Drug interactions

Drug or classInteractionRisk
CorticosteroidsGH + cortisol co-elevation may compound hyperglycemic effects of steroids.Moderate
Insulin / oral hypoglycemicsGH-induced insulin resistance — may increase diabetes medication requirements.Moderate

6.4 Long-term risks

  • Prolonged cortisol elevation and metabolic effects
  • IGF-1 mediated cancer risk
  • Pituitary desensitization with chronic supraphysiological dosing
  • Joint pain and carpal tunnel symptoms

6.5 Research best practices

  • Store at −20 °C; avoid repeated freeze-thaw
  • Administer fasted for optimal GH response
  • Use within 30 days of reconstitution
  • Space doses 3+ hours apart to avoid receptor desensitization
Safety data disclaimer. Safety assessments are based on published literature and are for educational reference only. Clinical evidence varies significantly between peptides. Always consult primary research and current regulatory guidance.

7 Frequently asked questions

How does GHRP-2 compare to other GH secretagogues?
GHRP-2 sits between Ipamorelin (most selective, mildest GH release) and Hexarelin (most potent, least selective) — providing strong GH release with intermediate cortisol/prolactin effects and less appetite stimulation than GHRP-6.
Can GHRP-2 diagnose GH deficiency?
Yes, GHRP-2 has been validated as a diagnostic provocation test for adult growth hormone deficiency, with sensitivity exceeding the traditional insulin tolerance test in some studies while avoiding the risks of inducing hypoglycemia.

8 References

  1. Growth Hormone-Releasing Peptide 2 May Be Associated With Decreased M1 Macrophage Production and Increased Histologic and Biomechanical Tendon-Bone Healing Properties in a Rat Rotator Cuff Tear Model PubMed (2025). Li Y, et al.. View source
  2. Assessment of anterior pituitary reserve capacity based on growth hormone response to growth hormone-releasing peptide-2 test in the elderly PubMed (2023). Teramoto S, et al.. View source
  3. Clinical Usefulness of the Growth Hormone-Releasing Peptide-2 Test for Hypothalamic-Pituitary Disorder PubMed (2022). Suzuki S, et al.. View source
  4. On the road of dried blood spot sampling for antidoping tests: Detection of GHRP-2 abuse PubMed (2021). Reverter-Branchat G, et al.. View source

Related compounds

Entries that share a target, a mechanism, or a research area with GHRP-2.

Ipamorelinanti-aging

Also targets GHSR-1a

A pentapeptide ghrelin mimetic renowned for its exceptional receptor selectivity. Unlike other GHSRs, Ipamorelin does not significantly raise cortisol, ACTH, or prolactin — making it a clean research tool for isolated GH axis studies.

Hexarelinanti-aging

Also targets GHSR-1a

A potent six-amino acid growth hormone secretagogue. Among the strongest GHRPs studied, but notable for also elevating cortisol and prolactin — making it useful for studying GH axis effects with concurrent stress-hormone activation.

CJC-1295anti-aging

Shares ghrh and pituitary pharmacology

A tetrasubstituted GHRH analog with four amino acid substitutions that increase receptor affinity and proteolytic resistance. Most commonly studied in combination with Ipamorelin for synergistic GH pulse amplification.

Sermorelinapproved

Shares ghrh and pituitary pharmacology

A synthetic 29-amino-acid fragment of growth hormone-releasing hormone (GHRH 1-29), FDA-approved as a diagnostic agent for GH deficiency. Stimulates the pituitary to release endogenous growth hormone.

Tesamorelinapproved

Shares pituitary and pulsatile pharmacology

A 44-amino acid GHRH analog with a trans-3-hexenoic acid N-terminal modification. FDA-approved for HIV-associated lipodystrophy. The most clinically validated GHRH analog for visceral adipose tissue reduction.

GHRP-6recovery

Shares release and pituitary pharmacology

A synthetic ghrelin-mimetic hexapeptide that potently stimulates GH release through the ghrelin receptor. One of the first growth hormone secretagogues developed, with over 25 years of research history.

9 See also

For research reference only. Not medical advice. Peptides may be regulated or restricted in your jurisdiction. Entry validated by the PeptidePlaza Biomedical Research Desk; see editorial standards.

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