GHRP-2

WADA Notice: GHRP-2 is prohibited under WADA S2.2.4 (Growth Hormone-Releasing Peptides), both in- and out-of-competition, on the 2026 WADA Prohibited List.

What is GHRP-2 (Pralmorelin)?

GHRP-2 (Growth Hormone Releasing Peptide-2, INN: pralmorelin) is a synthetic hexapeptide (D-Ala-D-β-Nal-Ala-Trp-D-Phe-Lys-NH₂) and a potent agonist of the growth hormone secretagogue receptor type 1a (GHS-R1a, ghrelin receptor). Developed from structure-activity relationship studies on enkephalin sequences, GHRP-2 stimulates pulsatile GH release from anterior pituitary somatotrophs via Gq/11-coupled PLCβ/IP3/Ca²⁺ signalling. It contains three unnatural D-amino acids (D-Ala, D-β-naphthylalanine, D-Phe) conferring enzymatic degradation resistance. Unlike ipamorelin (the first selective GHS-R1a agonist), GHRP-2 co-stimulates ACTH and cortisol at GH-releasing concentrations. Not FDA-approved. WADA S2.2.4. Supplied for laboratory research only.

Chemical Properties

How Does GHRP-2 Work?

GHS-R1a → Gq/PLCβ/IP3/Ca²⁺ → Pituitary GH Exocytosis: GHRP-2 binds GHS-R1a (ghrelin receptor) on anterior pituitary somatotrophs, activating Gq/11 → PLCβ → IP3 generation → Ca²⁺ release from somatotroph ER → GH vesicle exocytosis. Published data (Muccioli et al. 2007, PMID 17622734) document GHS-R1a as a Gq-preferring GPCR activated by both endogenous ghrelin and synthetic GHRPs, including GHRP-2. GHRP-2 is one of the most potent peptide GHS-R1a agonists, with greater GH-releasing activity than GHRP-6 or hexarelin at equivalent concentrations in comparative studies.

Non-Selective Co-Stimulation (ACTH/Cortisol): In contrast to ipamorelin (first selective GHS secretagogue; Raun et al. 1998, PMID 9849822), GHRP-2 co-stimulates ACTH and cortisol release at GH-releasing concentrations in preclinical and clinical data. This non-selective profile is attributed to GHS-R1a expression on corticotroph cells and GHRP-2's central CRH-stimulating activity. For research design: GHRP-2 is not appropriate as a tool compound when isolated GH axis activation without adrenal co-stimulation is required - use ipamorelin for that application.

What are the Potential Research Applications of GHRP-2?

• GHS-R1a high-potency reference agonist for competitive binding displacement assays and Gq/calcium mobilisation assays in GHS-R1a-transfected cell lines
• GHRP-2 vs ipamorelin selectivity comparison: quantifying ACTH/cortisol co-stimulation in primary pituitary cell cultures to characterise GHS-R1a vs corticotroph pathway contributions
• GHS-R1a Gq signalling pharmacology: IP3 accumulation, Ca²⁺ flux, and PKC activation dose-response in GHS-R1a-expressing cell models
• GHRP-2 + CJC-1295 DAC synergistic GH release: receptor pathway convergence and GH pulse amplitude amplification in somatotroph models

What are the Potential Side Effects of GHRP-2?

• ACTH and cortisol co-elevation documented in preclinical models at GH-releasing concentrations - adrenal pathway confound must be controlled in experimental designs with hormonal endpoints
• Appetite stimulation via ghrelin receptor activation in animal models - controls for food intake required in body composition endpoint studies
• No human safety data established for research-grade GHRP-2 at injectable concentrations. No long-term toxicity data. Data remains limited.

Risk & Handling

Handling Precautions

• Trained personnel only. Reconstitute in sterile water or 0.1% acetic acid under aseptic conditions. PPE: gloves, lab coat, eye protection.
• Handle as a CNS-active neuroendocrine research peptide. Institutional biosafety review recommended.

Exposure Risks

• Risk Tier: HIGH - Potent GHS-R1a agonist with documented GH, ACTH, and cortisol stimulation. No human safety data has been established for research-grade GHRP-2. No long-term toxicity data. Dependency potential via GH axis stimulation is plausible but uncharacterised.

Storage

• Store at −20°C sealed, light-protected. Reconstituted solution is stable for ~2–4 weeks at 2–8°C. Stable ≥24 months lyophilized.

FAQs

How does GHRP-2 differ from ipamorelin mechanistically?

Both activate GHS-R1a via Gq/Ca²⁺. Ipamorelin is selective - GH only, no ACTH/cortisol even at 200-fold ED50 (Raun et al. 1998). GHRP-2 co-stimulates ACTH and cortisol. GHRP-2 is the preferred tool compound when broader GHS-R1a pathway co-stimulation is the research target; ipamorelin when isolated GH axis activation is required.

WADA classification?

WADA S2.2.4 - Growth Hormone-Releasing Peptides. Prohibited in- and out-of-competition on the 2026 WADA Prohibited List.

References

• Muccioli G, Baragli A, Granata R, Papotti M, Ghigo E. Heterogeneity of ghrelin/growth hormone secretagogue receptors: toward the understanding of the molecular identity of novel ghrelin/GHS receptors. Frontiers in Neuroendocrinology. 2007;28(4):215–228. https://pubmed.ncbi.nlm.nih.gov/17622734/
• Raun K, Hansen BS, Johansen NL, et al. Ipamorelin, the first selective growth hormone secretagogue. European Journal of Endocrinology. 1998;139(5):552–561. https://pubmed.ncbi.nlm.nih.gov/9849822/

Disclaimer: GHRP-2 (Pralmorelin) is exclusively for laboratory research purposes. RCDbio products are not intended to diagnose, prevent, treat, or cure any disease or medical condition.

The Food and Drug Administration has not evaluated the statements on our website. This product is not approved for human or veterinary use. Researchers must comply with all applicable local, state, and federal laws and regulations governing the purchase and use of research compounds. By purchasing, you agree to our Terms and Conditions.

ATTENTION: All RCDbio products are strictly for LABORATORY AND RESEARCH PURPOSES ONLY. Contact support@rcdbio.co for queries.