GHRP-6
PeptideLast reviewed on June 1, 2026 by SupStaq
Not medical advice. This content is general, evidence-based information and is not a substitute for professional medical advice, diagnosis, or treatment.
The medical score (28) is substantially lower than the community score (58), as clinical efficacy evidence for bodybuilding indications in humans is lacking [s6, s8], while the community frequently reports subjective anabolic and regenerative effects [c1, c2]. The divergence reflects the typical gap between preclinical evidence and self-reporting in research peptides.
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TL;DR
GHRP-6 is a synthetic hexapeptide that stimulates growth hormone release via GHS-R1a receptor activation, engaging both pituitary and hypothalamic signaling pathways. The compound is experimental, not clinically approved, and carries an unfavorable benefit-risk profile (benefit 2/5, risk 3/5). Medical evidence is weak (28/100), while community reports suggest moderate effects. No therapeutic application in humans is scientifically established.
Description
Synthetic hexapeptide that triggers growth hormone pulses via activation of the ghrelin receptor (GHS-R1a); experimental, not approved [s1, s2].
GHRP-6 (Growth Hormone Releasing Peptide-6) is a synthetic hexapeptide with the amino acid sequence His-D-Trp-Ala-Trp-D-Phe-Lys-NH2. It was discovered in the 1980s by Cyril Bowers during work on enkephalin analogues and was the first synthetic peptide designed to specifically stimulate growth hormone secretion [s1, s2]. GHRP-6 binds to the GHS-R1a receptor (ghrelin receptor) in the pituitary gland and hypothalamus, thereby triggering a pulsatile rise in growth hormone (GH) [s1, s3]. Compared to GHRH, GHRP-6 acts via an independent receptor pathway, enabling synergistic combination with GHRH analogues (e.g., CJC-1295, Sermorelin) [s7]. Beyond GH release, GHRP-6 also activates the hypothalamic-pituitary-adrenocortical axis (HPA axis), which can lead to a transient increase in cortisol and prolactin [s4, s5]. A pronounced appetite stimulus through ghrelin release is the most commonly reported effect [s4, s5]. Preclinical studies (animal and cell models) demonstrate cardioprotective, anti-inflammatory, and tissue-preserving properties via the PI3K/Akt signaling pathway [s6]. A Phase I/II human study tested GHRP-6 in combination with EGF in acute ischemic stroke [s8]. Overall, clinical data in humans are very limited. GHRP-6 is not approved for human use. The substance is classified as a research chemical in Germany and is prohibited by WADA [s9, s10, s11].
Legal Status (DE)
GHRP-6 is not approved as a medicinal product in Germany and has no marketable status as a dietary supplement. It falls under the Medicinal Products Act (AMG) if marketed with a therapeutic intended purpose. Personal possession for self-use is legally ambiguous; commercial distribution to end consumers is not legally permitted. GHRP-6 is frequently declared as a "research chemical," which does not, however, constitute a legal exemption [s10, s11]. Furthermore, GHRP-6 is explicitly listed by WADA as a prohibited substance (category S2) — both in- and out-of-competition [s9].
Mechanism of Action
GHRP-6 exerts its effects primarily through two mechanisms [s1, s3]: 1. Direct GHS-R1a activation: GHRP-6 binds to the GHS-R1a receptor (ghrelin receptor) on somatotropic cells of the pituitary gland. This activates the Gq protein–PLC–calcium signaling pathway, resulting in growth hormone release [s3]. Simultaneously, GHS-R1a receptors in the hypothalamus are activated, which can further increase GHRH release [s1]. 2. Inhibition of somatostatin tone: GHRP-6 indirectly reduces the inhibitory effect of somatostatin on GH release, thereby amplifying the GH pulse [s2]. Side effects on other axes: - HPA axis: Activation leads to a transient cortisol increase [s4, s5]. - Prolactin axis: Elevated prolactin secretion at doses above 100 mcg [s5]. - Appetite: Ghrelin release stimulates the hunger center in the hypothalamus, resulting in strong appetite shortly after injection [s4]. Cytoprotective effects (preclinical): In animal and cell studies, GHRP-6 activates the PI3K/Akt signaling pathway in cardiac, hepatic, and neural tissue, mediating anti-apoptotic and anti-inflammatory effects [s6]. Reductions in TGF-β1, TNF-α, and oxidative stress, as well as promotion of mitochondrial biogenesis, have been observed in animal models [s6, s8]. The released GH secondarily stimulates IGF-1 production in the liver, which accounts for anabolic effects on muscle and bone tissue [s2].
Dosing
GH-Stimulation (allgemein)
- Dose
- 100 mcg per injection
- Frequency
- 2–3× täglich, subkutan
- Route
- injektion-subkutan
- Duration
- 8–12 Wochen, dann Pause
- Timing
- Inject fasted (at least 2h after last meal, at least 30 min before next meal), as glucose and fatty acids attenuate the GH response
- With food
- vermeiden
Kombination mit GHRH-Analogon (z. B. CJC-1295 no-DAC)
- Dose
- 100 mcg GHRP-6 + 100 mcg CJC-1295 (no-DAC) per injection
- Frequency
- 2–3× täglich, subkutan
- Route
- injektion-subkutan
- Duration
- 8–12 Wochen
- Timing
- Inject simultaneously fasted for synergistic GH pulse
- With food
- vermeiden
No officially validated maximum human dose exists, as GHRP-6 is not approved. Single doses above 300 mcg are not recommended in research protocols; at ≥100 mcg, the risk of cortisol and prolactin elevations increases [s5]. Any use outside controlled studies must be considered experimental [s10].
An insulin syringe (0.3–1 ml) is the standard administration device for subcutaneous injection. Bacteriostatic water or sterile water is used for reconstitution. No officially recommended human dose exists [s10].
Calculate reconstitution, plan dosing, look up injection technique
Side Effects
| Side Effect | Frequency | Severity |
|---|---|---|
| Starker Appetitreiz (Heißhunger) kurz nach der Injektion Ghrelin release activates hypothalamic hunger signaling pathways; this effect is the most frequent and characteristic distinction from more selective GHRPs such as ipamorelin [s4, s5]. | häufig | leicht |
| Transienter Cortisol-Anstieg HPA axis activation; at doses ≤100 mcg generally not clinically relevant according to study data, but detectable at higher doses [s5]. | gelegentlich | leicht |
| Transienter Prolaktin-Anstieg At doses >100 mcg; can lead to galactorrhea or loss of libido with prolonged use [s5]. | gelegentlich | leicht |
| Wassereinlagerungen (Ödeme) GH-induced sodium retention; typical for GH secretagogues, usually reversible upon discontinuation [s4]. | gelegentlich | leicht |
| Injektionsstellen-Reaktionen (Rötung, Schwellung, Schmerz) Local tissue irritation from subcutaneous injection; common with all peptide injections [s4]. | häufig | leicht |
| Kribbeln oder Taubheitsgefühl in Händen/Handgelenken GH-induced carpal tunnel syndrome-like symptom; described in community reports [c1]. | gelegentlich | leicht |
| Hitzewallungen, Schwindel nach Injektion Transient vasodilatory response following GHRP-6 injection; documented in user reports and case reports [c1]. | gelegentlich | leicht |
| Gynäkomastie (bei längerem Prolaktin-Anstieg) Theoretical with prolonged hyperprolactinemia; occasionally mentioned in community reports, no systematic data [s5, c1]. | selten | moderat |
| Verschlechterung der Insulinsensitivität GH can increase insulin resistance with prolonged use; relevant at supraphysiological GH levels [s2]. | theoretisch | moderat |
Contraindications
GH and IGF-1 can promote tumor growth; all GH secretagogues are contraindicated in active malignancy [s2].
GH elevation impairs insulin sensitivity and can significantly destabilize blood glucose [s2].
No human safety data available; prolactin elevation and unresolved effects on the fetus render use unacceptable [s10].
GHRP-6 can elevate prolactin and exacerbate pre-existing hyperprolactinemia [s5].
Impaired renal clearance of peptides; risk of accumulation and uncontrolled GH/IGF-1 levels possible [s13].
Further GH stimulation is counterproductive and potentially dangerous [s2].
Uncontrolled GH stimulation may affect epiphyseal plates and normal growth; no safety data available [s10].
Interactions
Synergistic
Combined use with GHRH analogues synergistically amplifies the GH pulse through dual receptor activation (GHS-R1a + GHRH-R) [s7].
Both activate GHS-R1a; GHRP-2 has slightly fewer appetite and cortisol side effects; structural similarity and additive GH stimulation possible when stacking [s14].
CJC-1295 DAC prolongs the GH pulse through extended GHRH receptor activation, while GHRP-6 triggers a rapid GH burst – the combination increases GH secretion more than either substance alone.
Sermorelin, as a GHRH analogue, complements GHRP-6 by activating the GHRH receptor, producing a more physiological and stronger GH pulse than either agent alone.
Ipamorelin and GHRP-6 both activate GHS-R1a, with ipamorelin being more selective and having fewer cortisol/prolactin side effects. Combination can provide an additive GH effect at low doses.
Hexarelin is the most potent GHRP and can be combined short-term with GHRP-6, though the risk of desensitization is increased with long-term stacking.
GHRP-6 combined with BPC-157 is used to support healing of tendons, joints, and muscles, as both peptides activate complementary regenerative mechanisms.
The combination of GHRP-6 and TB-500 is used to maximize recovery following injury or surgery, with both substances targeting distinct healing pathways.
Caution
GH elevation by GHRP-6 can increase insulin resistance and alter insulin requirements/dosing in diabetic patients; blood glucose monitoring required [s2].
Additive cortisol elevation possible; combined HPA axis activation of both substances may be clinically relevant [s5].
GH-induced insulin resistance may reduce the efficacy of antidiabetic agents and require dose adjustments [s2].
GHRP-6 increases prolactin; this may counteract the effect of cabergoline/bromocriptine [s5].
Simultaneous stacking of two or more GHRPs (e.g., ipamorelin + GHRP-6 + hexarelin) results in diminishing additional benefit alongside increased side effects such as elevated cortisol and prolactin levels and enhanced appetite.
Hexarelin has the highest desensitization rate among GHRPs; long-term combination with GHRP-6 may lead to rapid loss of efficacy of both substances.
Studies
Tier A: High Evidence
Outcome: Safety and tolerability of EGF+GHRP-6 combination in acute ischemic stroke; 30% serious adverse events as safety threshold
Effect Size: No safety signal above threshold; tolerability confirmed; functional outcomes exploratively positive
Tier B: Moderate Evidence
Outcome: Pharmacokinetic parameters (half-life, Cmax, AUC) following subcutaneous GHRP-6 injection
Effect Size: Short half-life (~15–30 min); rapid GH increase within 15–30 min post-injection
Outcome: GH response to GHRP-6 vs. GHRH in hypothyroid patients; GHRP-6 elicited significantly higher GH release than GHRH
Effect Size: Hypothyroid patients: GH 12.6 ± 1.9 µg/L after GHRP-6 vs. 4.1 ± 0.9 µg/L after GHRH (p < 0.05)
Tier C: Low Evidence
Outcome: Ventricular remodeling and systolic dysfunction following myocardial infarction; GHRP-6 reduced inflammatory cell infiltration and scar tissue
Effect Size: Significant improvement in cardiac endpoints vs. control; details in PMC full text
Community Evidence
Top reported benefits
- Increase in muscle mass when combined with CJC-1295
- Accelerated recovery after intense training
- Improved sleep (deep sleep phases)
- Mild fat reduction with consistent use
Top reported issues
- Extreme food cravings shortly after injection (very frequently reported)
- Cortisol and prolactin elevation as undesired side effects
- Preference for Ipamorelin or GHRP-2 due to better side effect profile
- Difficulties sourcing high-quality product
GHRP-6 is increasingly referred to in the community as a "dirty" GHRP, as it stimulates cortisol and prolactin in addition to GH [c1, c3]. Experienced users frequently advise more selective alternatives (Ipamorelin) or recommend GHRP-6 only in combination with CJC-1295 [c2]. The WADA prohibited status is largely known among athletes in the community [c1].
Scientific Sources
- GHRP-6 (Growth Hormone Releasing Peptide-6): Research Evidence & Safety Profile
PeptideInsight Editorial Team (2024). PeptideInsight (Online Resource)CLink - GHRP-6 – Wirkung, Anwendung und Risiken
Artgerecht.com Editorial Team (2024). Artgerecht.com Glossar (Online Resource)CLink - Peptide legal in Deutschland? Rechtslage 2026
Peptide Culture Editorial Team (2026). Peptide-Culture.com (Online Resource)CLink - GHRP-6 Protocol: Dosing, Timing & Cycle Guide (Peptide Dosages)
PeptideDosages.com Editorial Team (2024). PeptideDosages.com (Online Resource)CLink - Pharmacokinetic study of Growth Hormone-Releasing Peptide 6 (GHRP-6) in nine male healthy volunteers
Berlanga Acosta J, et al. (2004). ResearchGate / Peer-reviewed journal (original)BLink - GHRP-2 vs. GHRP-6: Die Feinheiten von Wachstumshormon-freisetzenden Peptiden im Detail
Anabolic Planner Editorial Team (2024). AnabolicPlanner.com (Online Resource)CLink - Growth hormone responses to GH-releasing peptide (GHRP-6) in hypothyroidism
Valcavi R, Zini M, Portioli I, et al. (1997). Clinical EndocrinologyBPMID:9156038 - Growth hormone releasing peptide-6 (GHRP-6) prevents doxorubicin-induced myocardial and extra-myocardial damages by activating prosurvival mechanisms
Berlanga-Acosta J, Cibrian D, Valiente-Mustelier J, Suárez-Alba J, García-Ojalvo A, Falcón-Cama V, Jiang B, Wang L, Guillén-Nieto G (2024). Frontiers in PharmacologyCPMID:38873418DOI - On the in vitro and in vivo activity of a new synthetic hexapeptide that acts on the pituitary to specifically release growth hormone
Bowers CY, Momany FA, Reynolds GA, Hong A (1984). EndocrinologyCLink - GHRP-6: Growth Hormone Releasing Peptide-6 Guide
Peptidepedia Editorial Team (2024). Peptidepedia (Online Resource)CLink - GHRP-6: Complete Science Guide
PeptideBond Editorial Team (2024). PeptideBond.com (Online Resource)CLink - GHRP-6 side effects and safety considerations
Peptides Lab UK Editorial Team (2024). PeptidesLabUK (Online Resource)CLink - GHRP-6 Nebenwirkungen
Steroidzentrum.de Editorial Team (2023). Steroidzentrum.de (Online Resource)CLink - Growth Hormone-Releasing Peptide-6 (GHRP-6) Ameliorates Post-Infarct Ventricular Remodeling and Systolic Dysfunction in a Model of Permanent Coronary Ligation
Unpublished Authors et al. (2025). PMC / PubMed CentralCLink - GHRP-6 Protocol: Dosing, Timing & Cycle Guide
ThePeptideGuides Editorial Team (2024). ThePeptideGuides.com (Online Resource)CLink - Combination therapy of Epidermal Growth Factor and Growth Hormone-Releasing Hexapeptide in acute ischemic stroke: a phase I/II non-blinded, randomized clinical trial
Rodriguez Blanco S, Verdecia Jarque M, Fernandez Mayola M, et al. (2024). Frontiers in NeurologyADOI - The Prohibited List 2025 — World Anti-Doping Code International Standard
World Anti-Doping Agency (2024). WADA (World Anti-Doping Agency)ALink
Community Sources
Storage
Unopened
Lyophilized powder: store at 2–8 °C (refrigerator) or at -20 °C for long-term storage. Protection from light required.
Opened
After reconstitution with bacteriostatic water: store at 2–8 °C, use within 28–30 days. Do not freeze after reconstitution.
Notes
Peptides are sensitive to heat, light, and repeated freeze/thaw cycles. Sterility must be strictly maintained during reconstitution.