GHRP-2

GHRP-2 (Growth Hormone Releasing Peptide 2) is a synthetic hexapeptide that selectively binds the ghrelin/GHS-R1a receptor on the pituitary gland, stimulating release of growth hormone (GH). It is part of the GHRP family along with GHRP-6, hexarelin, and ipamorelin. GHRP-2 is one of the most potent GHRPs at GH release per microgram but, unlike ipamorelin, also causes a modest rise in prolactin and cortisol. It is sold strictly for laboratory research.

GHRP-2 is one of the original research peptides used to study growth hormone pulses. It acts on the ghrelin receptor (the same receptor that gets activated when you are hungry) to tell the pituitary to release a burst of GH. It is potent, fast-acting, and reliable in research. The downside compared to ipamorelin is that it also slightly raises cortisol and prolactin — which most forum users want to avoid — and is well known to increase appetite.

GHRP-2 binds the growth hormone secretagogue receptor (GHS-R1a) on pituitary somatotrophs, triggering calcium-mediated GH release. This signal is independent of and synergistic with GHRH, which is why GHRP-2 is often paired with a GHRH analog (CJC-1295, sermorelin, tesamorelin) in research to amplify the pulse.

Second-generation growth hormone-releasing peptide. Robust GH release with mild side-effect profile.

1. GHRP-2
2. GHRH and/or ghrelin receptors in the pituitary
3. Pulsatile growth hormone release
4. Downstream IGF-1, body-composition and recovery endpoints

A plain-English read on how much published evidence currently exists for GHRP-2. These ratings describe the volume and maturity of the literature — not effectiveness, safety, or suitability for any use.

Current limitations: most compounds in this category are studied in preclinical or small-sample settings. Absence of large controlled human trials is the single biggest limitation to keep in mind when reading any summary of GHRP-2.

Lyophilized compounds are supplied as a dry powder. Concentration is simply the total amount in the vial divided by the volume of bacteriostatic water added:

Concentration (mg/mL) = total mg in vial ÷ mL of diluent added

Commonly supplied vial sizes

5mg vial

Worked concentration example

5mg + 2mL BAC water → 2.5mg/mL On U-100 insulin syringe:

• • 4 units = 100mcg

Run your own numbers with the reconstitution calculator — it converts vial size and diluent volume into mg/mL and mcg/mL.

The figures below are reported here descriptively, because they are the values most frequently cited in publicly available research literature and reference material. They are not instructions, not a protocol, and not a recommendation. These compounds are supplied for laboratory research use only and are not approved by the FDA for human consumption.

Commonly cited amounts

100mcg, 2–3× daily subcutaneous

Commonly cited frequency

2–3× daily

Commonly cited study duration

8–12 weeks

Peptides are supplied freeze-dried because peptide bonds degrade far faster in solution than in a dry state. Understanding storage is part of understanding why the powder form exists at all.

• •Lyophilized powder: stored refrigerated, typically stable for months to years.
• •Reconstituted solution: refrigerated at 2–8°C, generally discussed as stable for roughly 30–60 days.
• •Heat and direct light accelerate degradation — vials are kept cool and dark.
• •Reconstituted material is not re-frozen; ice crystal formation disrupts peptide structure.
• •Bacteriostatic water contains 0.9% benzyl alcohol as a preservative, which is what allows multi-day storage after reconstitution.

More detail in the storage & handling guide and how peptide quality is evaluated.

• •GH-axis stimulation testing
• •Adult GH deficiency diagnostic research
• •Ghrelin and appetite regulation
• •Comparative GHRP pharmacology
• •Cortisol and prolactin off-target effects

GHRP-2 was once the default GHRP in research peptide stacks but has been largely replaced by ipamorelin for most users, because ipamorelin produces a cleaner GH pulse without raising cortisol or prolactin. GHRP-2 remains favored by users who specifically want appetite stimulation alongside GH release, or by those running diagnostic-style research protocols.

“Potent GH pulse, but bring an appetite.”

Almost always discussed in combination with a GHRH analog — most commonly CJC-1295 (with or without DAC). This is the classic 'GHRP + GHRH' synergy. Pairing with ipamorelin is uncommon because ipamorelin is functionally a cleaner replacement for GHRP-2.

GHRP-2 is a potent ghrelin-receptor-binding hexapeptide that stimulates pulsatile growth hormone release. It also raises appetite, cortisol, and prolactin modestly, which is why ipamorelin has largely replaced it in most modern research stacks. It is sold for laboratory research only.