GHRP-6 (Growth Hormone Releasing Hexapeptide)
GHRP-6 is the original growth hormone releasing peptide, a synthetic hexapeptide that binds the ghrelin receptor (GHS-R1a). It produces the strongest appetite stimulation of any GHRP and has unique cardioprotective data from Cuban research showing 78% reduction in infarct mass in MI models. Phase I PK study confirmed a 2.5-hour elimination half-life.
FormBlends Peptide Context
Reviewed May 14, 2026Use Ghrp 6 peptide guide as a decision-support page, not a shortcut. Its job is to frame benefits, dosing, evidence strength, sourcing, and safety boundaries in one place, especially where the search overlaps with peptide therapy. A useful reader should leave with better questions about clinician oversight, evidence quality, safety limits, cost, pharmacy path, and what changes for their own health history.
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Clinical decision snapshot
GHRP-6 authority snapshot
GHRP-6 is evaluated by mechanism, evidence quality, regulatory status, practical access, and safety questions a licensed clinician would need to review before use.
Evidence signal
Meaningful evidence with limits
Regulatory reality
Expected to remain Category 2 (restricted from compounding)
Safety screen
Strong appetite increase (the most intense of any GHRP), Cortisol elevation of 25-35% (transient), Prolactin elevation of 15-25% (transient) should be reviewed in context.
This page currently connects to 6 source-backed evidence items through visible references or structured citation data.
Decision path
What is the supervised-review path for GHRP-6?
GHRP-6 should be evaluated by evidence quality, safety status, source quality, dosing context, and whether the goal fits a legitimate clinical pathway. This page is a research and decision aid, not a self-prescribing guide.
- Peptide
- GHRP-6
- Category
- Growth Hormone
- Evidence
- Meaningful evidence with limits
- FDA status
- Not FDA approved
Step 1
Check evidence level
GHRP-6 has Phase I human PK data (Mendez et al., Eur J Pharm Sci 2013, PMID: 23099431) showing bi-exponential kinetics with a 2.5-hour elimination half-life. Berlanga-Acosta et al. (Clinical Science 2007, PMID: 16989643) showed 78% infarct mass reduction and 50% less wall thinning in MI models. Bowers et al. (JCEM 1995) confirmed GH responses don't decline in late adulthood.
Review evidenceStep 2
Screen safety context
Strong appetite increase (the most intense of any GHRP), Cortisol elevation of 25-35% (transient), Prolactin elevation of 15-25% (transient) should be discussed in light of history, dose, and source.
Check side effectsStep 3
Confirm access route
If FormBlends offers access, review the product page and provider pathway before deciding.
Review product accessLast updated: April 6, 2026
Typical Dosage
100-300 mcg subcutaneous injection, 1-3 times daily on an empty stomach. Expect strong hunger within 20 minutes. Avoid eating fats/carbs 30 minutes before or after to maximize GH pulse.
Administration
Subcutaneous injection
Typical Cost
$15-40 per 5 mg vial (research); $80-200/month compounded
FDA Status
Not FDA Approved
Half-Life
Distribution half-life 7.6 minutes; elimination half-life 2.5 hours. GH pulse duration approximately 60-90 minutes.
Onset of Action
Peak GH at 15-30 minutes post-SC injection. Appetite stimulation within 20 minutes.
Bioavailability
High via subcutaneous injection. Less than 1% orally.
About GHRP-6
GHRP-6 (Growth Hormone Releasing Peptide-6) is a synthetic hexapeptide with the sequence His-D-Trp-Ala-Trp-D-Phe-Lys-NH2. CAS number: 87616-84-0 (free base). Molecular weight: 873.01 Da. GHRP-6 was the first growth hormone releasing peptide discovered, and it remains the least selective of the family. That lack of selectivity is both its weakness and, in certain contexts, its strength. It hits the ghrelin receptor hard, which means potent GH release, but it also activates NPY/AgRP neurons in the hypothalamus more aggressively than any other GHRP. The result is intense hunger that kicks in about 20 minutes after injection. For people recovering from illness, surgery, or cachexia, that appetite drive is exactly what they need. For people trying to manage body composition, it's a liability. The cardioprotective data is where GHRP-6 gets genuinely interesting. Berlanga-Acosta's group at Cuba's Center for Genetic Engineering and Biotechnology (CIGB) published a 2007 study in Clinical Science (PMID: 16989643) showing that GHRP-6 reduced infarct mass by 78% and wall thickness loss by 50% in a myocardial infarction model. A follow-up showed post-MI mortality of 6.7% in the GHRP-6 group versus 50% in vehicle controls. These effects appear to be mediated through CD36 receptors on cardiac tissue rather than through GH release, which makes them mechanistically distinct from the peptide's growth hormone effects. A 2024 Frontiers in Pharmacology study showed GHRP-6 protected against doxorubicin-induced organ damage by enhancing antioxidant reserves and upregulating anti-apoptotic Bcl-2 pathways. This cytoprotective property extends beyond the heart to hepatic and neural tissue. Phase I pharmacokinetics were characterized by Mendez et al. (European Journal of Pharmaceutical Sciences 2013, PMID: 23099431) in 9 healthy male volunteers. IV doses of 100-400 mcg/kg showed bi-exponential kinetics with a distribution half-life of 7.6 minutes and an elimination half-life of 2.5 hours. AUC increased proportionally with dose. Like GHRP-2, GHRP-6 raises cortisol (~25-35%) and prolactin (~15-25%) transiently. This is why ipamorelin has become the clinical GHRP of choice: it provides clean GH release without these hormonal side effects. GHRP-6 stays relevant primarily for its appetite-stimulating properties and the unique cardioprotective research. GHRP-6 is expected to remain on the FDA Category 2 restricted list along with GHRP-2. Neither was included in the 14 peptides returning to Category 1 under the 2026 HHS announcement. The cortisol and prolactin elevation were cited as contributing safety concerns.
How GHRP-6 Works
GHRP-6 activates GHS-R1a through the same Gq/11 signaling cascade as GHRP-2. What sets it apart is stronger ghrelin-mimetic activity in the hypothalamus, where it strongly activates NPY/AgRP neurons in the arcuate nucleus. This drives the intense appetite stimulation that GHRP-6 is known for. It also targets CD36 scavenger receptors, which may explain the cytoprotective effects seen in cardiac, hepatic, and neural tissue. Cryo-EM studies have mapped its binding pocket within GHS-R1a, revealing unique accommodation for its D-amino acid residues.
Receptor targets:
Benefits
- Strong GH release through ghrelin receptor activation
- Most potent appetite stimulation of any GHRP (useful for wasting/cachexia)
- 78% reduction in infarct mass in myocardial infarction models (Berlanga-Acosta et al.)
- Cytoprotective properties in cardiac, hepatic, and neural tissue
- GH response does not decline with age
- Synergistic with GHRH analogs for amplified GH output
What Does the Research Say?
GHRP-6 has Phase I human PK data (Mendez et al., Eur J Pharm Sci 2013, PMID: 23099431) showing bi-exponential kinetics with a 2.5-hour elimination half-life. Berlanga-Acosta et al. (Clinical Science 2007, PMID: 16989643) showed 78% infarct mass reduction and 50% less wall thinning in MI models. Bowers et al. (JCEM 1995) confirmed GH responses don't decline in late adulthood.
Pharmacokinetic study of Growth Hormone-Releasing Peptide 6 (GHRP-6) in nine male healthy volunteers
European Journal of Pharmaceutical Sciences, 2013 · DOI · PubMed
Bi-exponential PK with distribution half-life of 7.6 minutes and elimination half-life of 2.5 hours; dose-proportional AUC at 100-400 mcg/kg IV
Growth-hormone-releasing peptide 6 (GHRP-6) prevents oxidant cytotoxicity and reduces myocardial necrosis in a model of acute myocardial infarction
Clinical Science, 2007 · DOI · PubMed
GHRP-6 reduced infarct mass by 78% and wall thickness loss by 50% in an MI model, effects independent of GH release
Synthetic Growth Hormone-Releasing Peptides: A Historical Appraisal of the Evidences Supporting Their Cytoprotective Effects
Clinical Medicine Insights: Cardiology, 2017 · DOI · PubMed
Full review establishing GHRPs as cytoprotective agents with cardioprotective, neuroprotective, and hepatoprotective properties independent of GH release
PubMed evidence trail
Research sources used to frame this page
For GHRP-6, FormBlends checks the page topic against primary trials, systematic reviews, guidelines, and current PubMed-indexed literature where available. These citations are context, not a claim that every study applies to every patient.
Ipamorelin, the first selective growth hormone secretagogue
Background source for ipamorelin selectivity and GH-secretagogue mechanism.
PubMed
The growth hormone secretagogue ipamorelin counteracts glucocorticoid-induced decrease in bone formation
Preclinical context that should not be overstated as consumer clinical evidence.
PubMed
Potential Side Effects
- Strong appetite increase (the most intense of any GHRP)
- Cortisol elevation of 25-35% (transient)
- Prolactin elevation of 15-25% (transient)
- Water retention (mild to moderate)
- Injection site reactions
- Decreased insulin sensitivity (FDA concern)
- Gastric motility increase and cramping in some users
Drug Interactions
| Compound | Interaction | Severity |
|---|---|---|
| Somatostatin analogs (octreotide) | Directly antagonize GH release. Will blunt GHRP-6 effect. | major |
| GHRH analogs (sermorelin, CJC-1295) | Synergistic GH release far greater than either alone. Standard stacking protocol. | moderate |
| Insulin and oral hypoglycemics | GH elevation decreases insulin sensitivity transiently. Monitor glucose. | moderate |
Who Is GHRP-6 For?
Women
No sex-based differences in GH response. Response is independent of menstrual cycle phase. Same cortisol and prolactin effects apply.
Adults Over 50
GH secretion after GHRP-6 does not decline in late adulthood (Bowers et al., JCEM 1995). The strong elderly response suggests age-related GH decline is functional and reversible, making this a key area of research interest.
Athletes
Prohibited at all times by WADA under S2. Detectable via LC-MS/MS in urine. Strict liability applies.
Regulatory Status
FDA Approved
No
Compounding Legal
No
2026 HHS Status
Expected to remain Category 2 (restricted from compounding)
GHRP-6 was placed on the FDA Category 2 restricted list and is expected to remain restricted. Like GHRP-2, it was excluded from the 14 peptides returning to Category 1 under the February 2026 HHS announcement.
Last verified: 2026-04-06
Stacking Options
GHRP-6 is commonly stacked with the following peptides for enhanced results:
Conditions Addressed
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