Growth Hormone

GHRP-6

Growth Hormone Releasing Peptide 6

First-generation GHS-R1a hexapeptide. Hunger, cortisol, and prolactin are class effects. Research chemical, not a cachexia drug and not ipamorelin.

Not FDA-approved - research chemicalWADA (S2) - prohibited in sport at all times
Reviewed by CalcMyPeptide Editorial Team
Last updated: August 2026Evidence: Moderate1 peer-reviewed citation
Typical research dose
100-300 mcg/injection
Frequency
2-3× daily
Half-life
~15-60 minutes
Common vials
5 mg
CAS
87616-84-0
Molecular weight
873.01 g/mol

Use-case scores

0–10 against the evidence we have, not a gym ranking. Hidden domains do not apply here.

  • Muscle / recomp3.5/10

    GH-release hexapeptide with appetite/cortisol/prolactin baggage. Community use, not a hypertrophy RCT.

Compound card

Sequence
His-D-Trp-Ala-Trp-D-Phe-Lys-NH2
Class
First-generation GHS-R1a hexapeptide (ghrelin mimetic)
Formula
C46H56N12O6
Status
Not FDA-approved · research use
Dose it
5 mg + 2.5 mL BAC water → 2 mg/mL · 100 mcg ≈ 5 units (U-100)
Open in calculator

How it works

GHRP-6 is a first-generation hexapeptide growth hormone releasing peptide that activates the ghrelin receptor (GHS-R1a) on pituitary somatotroph cells. It produces a strong, dose-dependent GH release pulse. Unlike Ipamorelin, GHRP-6 is non-selective - it also significantly stimulates appetite via the ghrelin pathway, elevates cortisol, and increases prolactin.

The appetite-stimulating effect is pronounced and is considered either a benefit or drawback depending on the user's goals. For individuals seeking to increase caloric intake (e.g., recovery from illness or muscle building), this is advantageous.

Source: PMID: 9003422

Background & History

GHRP-6 is Bowers’ first-generation GHS-R1a hexapeptide. Hunger, cortisol, and prolactin are class effects. A research cake is not a cachexia drug.

Research Use Cases

  • ✓First-generation GHRP identity vs ipamorelin
  • ✓Appetite as a class effect, not a feature label
  • ✓Not cancer/HIV cachexia treatment

Dosing

PhaseDoseFrequencyNotes
Standard Protocol100 - 300 mcg2-3× dailyInject fasted. Strong appetite stimulation within 15-20 min of injection is expected.

Administration

Route / form
Subcutaneous injection
Timing
Must inject fasted. Best times: upon waking, pre-workout, and before bed.
Empty stomach?
Yes - Empty stomach (typical for this injectable class).

Timeline

Immediately
Strong appetite stimulation within 15-20 minutes of injection.
Week 1-4
GH pulse increases, improved recovery, enhanced caloric intake advantageous for mass building.
Month 2-3
Body composition improvements. Most pronounced in caloric surplus contexts.

Who it is for

Muscle Building / Caloric Surplus

High

Appetite stimulation is a feature, not a bug, for hardgainers and mass-building phases.

GH Optimization

Moderate

Strong GH pulse - less selective than Ipamorelin but potent raw output.

Reconstitution

VialWaterConcentrationExample dose
5 mg lyophilized2.5 mL BAC2 mg/mL200 mcg = 0.10 mL = 10 units on a U-100.

Change vial size or water volume? Open the reconstitution calculator.

Safety & Considerations

Research peptide. Strongly stimulates appetite - be aware of this if weight management is a goal. May elevate cortisol and prolactin temporarily. Use on an empty stomach.

Regulatory & Legal Status

FDA Status (US)
Research Only
WADA Status (2026)
Prohibited (S2)

Competitive athletes subject to anti-doping controls should not use GHRP-6.

Classification

Research Chemical

US Compounding: Not eligible / not available

⚠️ This information is for educational purposes only and may not reflect the most current regulatory updates. Always verify with official FDA, WADA, and jurisdiction-specific sources before use.

Limits of current evidence

  • Appetite, cortisol, and prolactin are class effects, not “dirty rumor.”
  • This is not a cachexia drug page and not a pediatric GHD protocol.

Verdict

GHRP-6 is the hungry first-generation ghrelin mimetic. The hunger is the mechanism, not a bonus stack. It is not ipamorelin and not somatropin.

Interactions & Contraindications

Appetite and cortisol make this a poor “clean GH” story. Diabetes/insulin resistance watching. Empty stomach for a pulse.

Synergies & Common Stacks

+ CJC-1295 no DAC →

GHRH+GHRP mix with more off-target than ipamorelin. Not a GI-healing pair with BPC-157.

GHRP-6 vs. Ipamorelin

Canonical comparison: GHRP-6 vs Ipamorelin

AttributeGHRP-6Ipamorelin
SelectivityNon-selective (GH + cortisol + hunger)Selective (GH only)
Appetite EffectStrong - great for hardgainersMinimal
GH OutputStrong GH pulseModerate, clean GH pulse
Side Effect ProfileHunger, cortisol, water retentionMinimal - transient water retention
Best ForBulking, aggressive muscle-buildingLong-term anti-aging, fat loss protocol

Verdict: GHRP-6 outperforms Ipamorelin on GH pulse intensity and appetite stimulation - valuable for aggressive muscle-building phases. For a clean, selective, long-term protocol, Ipamorelin is preferable.

Frequently Asked Questions

Does GHRP-6 make you hungry?▼
Yes - GHRP-6 strongly stimulates appetite via the ghrelin pathway. This is its most notable side effect and is typically felt within 15-20 minutes of injection. If appetite stimulation is undesirable, Ipamorelin is a better choice.
What is the standard GHRP-6 dose?▼
100-300 mcg per injection, 2-3 times daily on an empty stomach. Often combined with a GHRH analog like CJC-1295 (no DAC) for synergistic GH release.
How does GHRP-6 compare to GHRP-2?▼
GHRP-2 is more potent for GH release with less appetite stimulation. GHRP-6 produces a stronger hunger response. Both elevate cortisol and prolactin more than Ipamorelin.

References

  1. Bowers CY “"Growth hormone-releasing peptides".” Journal of Pediatric Endocrinology & Metabolism (1993). PMID: 8186715

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