GHRP-6 Dosing Guide: Protocols (2026)

GHRP-6 (Growth Hormone Releasing Peptide-6) is a synthetic hexapeptide that potently stimulates growth hormone secretion through the ghrelin/GHS receptor. It was one of the first GH secretagogues developed and remains widely used despite newer alternatives like ipamorelin.

The most hunger-inducing GHRP: GHRP-6's strong ghrelin receptor activation makes it uniquely effective for those seeking appetite stimulation alongside GH release, but problematic for those managing caloric intake. This is not medical advice.

Quick Reference: Community Dosing

Standard protocol: 100 mcg subcutaneous 3x daily (morning, pre-workout, bedtime) on an empty stomach. Saturation dose: ~100 mcg per injection is considered near-maximal for GH release per bolus.

For the full GHRP-6 peptide profile and comparison guides, see our GHRP-6 Complete Guide and GHRH vs GHRP comparison.

Loading vs Maintenance

GHRP-6 doesn't require a loading phase but benefits from strategic timing:

Week 1 (Assessment): Start at 100 mcg once daily (bedtime) to gauge hunger response and GH effects. Hunger is the most immediate indicator of peptide activity.

Weeks 2–16 (Full protocol): Increase to 100 mcg 2–3x daily. Three daily injections provide pulsatile GH release mimicking natural secretion patterns.

Cycling rationale: Extended GHRP-6 use may lead to pituitary desensitization. The 8–16 week on / 4–8 week off approach helps maintain receptor sensitivity.

Optimal Injection Timing

• Morning (fasted): Upon waking, before breakfast — capitalizes on natural AM cortisol/GH dynamics
• Pre-workout: 30–60 minutes before training on empty stomach
• Before bed: 30–60 minutes before sleep, at least 2 hours after dinner — synergizes with nocturnal GH pulse
• Food timing critical: Fats and carbohydrates suppress GH response; inject fasted, eat 20–30 min after

Routes of Administration

Subcutaneous Injection (Standard)

The primary and most effective route for GHRP-6:

• Injection sites: Lower abdomen, love handles — rotate daily
• Volume: Very small — typically 0.04–0.12 mL per injection
• Needle: 29–31 gauge, ½ inch insulin syringe
• Onset: GH release begins within 5–15 minutes; hunger within 15–30 minutes

Oral Administration (Studied but Less Effective)

GHRP-6 has been studied via oral and intranasal routes with retained GH-releasing activity, though at significantly lower potency than subcutaneous injection (Bowers et al., 1995).

Reconstitution Guide

Where These Numbers Come From: Clinical Context

GHRP-6 has more human clinical data than many research peptides, as it was extensively studied in endocrinology research.

GH Release Studies

GHRP-6 is a synthetic hexapeptide that specifically stimulates GH secretion both in vitro and in vivo. Studies demonstrated its mechanism involves phosphatidylinositol turnover in pituitary somatotroph cells (Lei & Bhargava, 1995).

GHRH Synergy

Research established that GHRP-6 requires endogenous hypothalamic GHRH for maximal GH stimulation, explaining the synergistic effects when co-administered with GHRH analogs (Pandya et al., 1998).

Oral Bioavailability

Clinical studies in children demonstrated that oral GHRP-6 retains GH-releasing activity, confirming the peptide's activity across multiple routes of administration, though subcutaneous remains most potent (Bowers et al., 1995).

Cytoprotective Properties

Beyond GH release, GHRP-6 has demonstrated cardioprotective and cytoprotective properties independent of GH pathways, acting through GH secretagogue receptor-mediated mechanisms in cardiac and other tissues (Berlanga-Acosta et al., 2017).

Appetite Mechanism

GHRP-6 activates the ghrelin receptor (GHS-R1a), the same receptor stimulated by the endogenous hunger hormone ghrelin. Central administration of GHRP-6 activates appetite centers in the hypothalamus, including orexin-containing neurons in the lateral hypothalamus (Wren et al., 2001).

Mechanism of Action

GHRP-6 works through ghrelin receptor activation with several downstream effects:

GHS-R1a receptor agonism — GHRP-6 binds and activates the growth hormone secretagogue receptor type 1a on pituitary somatotrophs, triggering intracellular calcium release and GH secretion (Lei & Bhargava, 1995).

Hypothalamic GHRH amplification — GHRP-6 also acts at the hypothalamic level to stimulate endogenous GHRH release, creating a dual mechanism of GH stimulation (direct pituitary + hypothalamic). Maximum GH release requires endogenous GHRH (Pandya et al., 1998).

Somatostatin suppression — GHRP-6 acts as a functional somatostatin antagonist, reducing the inhibitory tone on GH release. This allows larger GH pulses than GHRH alone can achieve.

Appetite stimulation — Via central GHS-R1a activation, GHRP-6 activates orexigenic pathways in the arcuate nucleus and lateral hypothalamus, producing pronounced hunger 15–30 minutes post-injection (Wren et al., 2001).

Cortisol and prolactin release — Unlike more selective GHRPs (ipamorelin), GHRP-6 stimulates ACTH/cortisol and prolactin secretion, particularly at higher doses. This is considered a less desirable effect.

IGF-1 elevation — Sustained GH release from GHRP-6 protocols leads to hepatic IGF-1 production, mediating many of the growth and recovery benefits.

Side Effects & Safety

GHRP-6 has a well-characterized side effect profile due to its extensive study history:

Common Side Effects

• Intense hunger — The hallmark side effect; 15–30 minutes post-injection, can last 30–60 minutes. Most pronounced of all GHRPs
• Water retention — Mild, GH-mediated fluid retention, particularly in hands/feet
• Cortisol elevation — Dose-dependent ACTH/cortisol stimulation, more significant than ipamorelin or GHRP-2
• Prolactin elevation — Mild increases at standard doses; more pronounced at >200 mcg
• Injection site reactions — Minor redness, occasional itching

Less Common Side Effects

• Numbness/tingling — Transient paresthesias in hands, related to GH-induced fluid shifts
• Dizziness — Occasionally reported post-injection, usually brief
• Headache — Mild, typically in the first week of use
• Blood sugar effects — GH opposes insulin; monitor if diabetic or insulin-resistant

Safety Considerations

• Pituitary desensitization — Prolonged continuous use may reduce receptor sensitivity; cycling helps prevent this
• Cortisol accumulation — Multiple daily doses can compound cortisol elevation; monitor stress/recovery
• Insulin sensitivity — Chronic GH elevation can reduce insulin sensitivity
• Cancer caution — Elevated GH/IGF-1 is theoretically concerning for cancer promotion; avoid with active malignancy

Stacking GHRP-6

GHRP-6 is most effective when paired with GHRH analogs for synergistic GH release:

GHRP-6 + CJC-1295 (Gold Standard GH Stack)

Synergistic GH release through complementary receptor pathways:

• GHRP-6 → ghrelin receptor activation (pituitary + hypothalamus)
• CJC-1295 → GHRH receptor activation (direct pituitary stimulation)

GHRP-6 + Ipamorelin (Moderate Stack)

Combining two GHRPs for broader receptor engagement:

• GHRP-6 → strong GH release + appetite stimulation
• Ipamorelin → clean GH release, no cortisol/prolactin

GHRP-6 + MK-677 (Oral + Injectable)

Sustained GH elevation through different half-lives:

• GHRP-6 → acute pulsatile GH release (short half-life)
• MK-677 → oral GH secretagogue, 24-hour half-life

Bulking-Specific Stack

For those leveraging GHRP-6's appetite stimulation:

• GHRP-6 → GH release + increased appetite for caloric surplus
• CJC-1295 → amplified GH response
• BPC-157 → gut health support for high caloric intake

Stacking Considerations

• Same syringe: GHRP-6 and GHRH analogs can be combined in the same syringe
• Fasted requirement: Both GHRP and GHRH analogs require empty stomach
• Cortisol monitoring: Stacking multiple GH secretagogues can compound HPA axis effects
• Saturation doses: Each GHRP has a per-injection ceiling; stacking doesn't bypass individual receptor saturation

Frequently Asked Questions

What is the standard GHRP-6 dose?

100 mcg subcutaneous 2–3 times daily on an empty stomach. This is considered near the saturation dose for maximal GH release per injection.

Does GHRP-6 increase hunger?

Yes — significantly. GHRP-6 activates the ghrelin receptor, producing intense hunger 15–30 minutes post-injection. This is the most pronounced appetite effect of any GHRP, making it beneficial for bulking but challenging for cutting.

Should GHRP-6 be taken on an empty stomach?

Yes — fats and carbohydrates blunt the GH response. Wait at least 2 hours after eating, and 20–30 minutes after injection before consuming food.

How does GHRP-6 compare to GHRP-2?

GHRP-6 causes much more hunger. GHRP-2 may produce slightly higher GH output per dose with less appetite stimulation and lower cortisol/prolactin elevation. Choose GHRP-6 if appetite stimulation is desired.

Can GHRP-6 be stacked with CJC-1295?

Yes — this is the standard GH-releasing stack. The combination produces synergistic GH release far exceeding either peptide alone. They can be mixed in the same syringe.

How do I reconstitute GHRP-6?

Add 2 mL bacteriostatic water to a 5 mg vial (2,500 mcg/mL). 100 mcg = 4 units on an insulin syringe. Swirl gently, refrigerate, use within 28 days.

Related Guides

• GHRP-6 Complete Guide — Full profile, research, and comparison
• GHRP-2 Dosing Guide — Lower-hunger alternative GHRP
• Ipamorelin Dosing Guide — Cleanest GHRP, no hunger/cortisol
• Hexarelin Dosing Guide — Strongest GHRP by GH output
• CJC-1295 + Ipamorelin Guide — GHRH+GHRP combination protocols
• GHRH vs GHRP — Understanding the two classes of GH secretagogues

References

For educational and research purposes only. This is not medical advice. GHRP-6 has clinical research data but is not FDA-approved for general use.