Side-by-side · Research reference

GHRP-6vsHexarelin

Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.

APhase 1Reviewed10/36 cited

BPhase 1Reviewed19/45 cited

GHRP-6

Hexapeptide GHRP · Strong appetite stimulant

100–200 mcgPer doseBowers 1990

Phase 1Evidence levelBowers 1990

~15 minHalf-lifeMalagón 1999

SQ · Multiple sites · 1–3×/day

Hexarelin

Hexapeptide GHRP · Cardio-tropic

100–200 mcgPer doseSmith 1996

Phase 1Evidence levelGhigo 1997

~70 minHalf-lifeSemenistaya 2010

SQ · Multiple sites · 1–3×/day

01Mechanism of Action

Parameter

GHRP-6

Hexarelin

Primary target

Ghrelin receptor (GHS-R1a)Bowers 1990

Ghrelin receptor (GHS-R1a) + cardiac CD36Smith 1996 Ghigo 1997

Pathway

GHS-R1a → Gαq → Ca²⁺ → GH release; central appetite driveBowers 2002

GHS-R1a → Gαq → Ca²⁺ → GH release. CD36 engagement → direct cardio-tropic actionGhigo 1997

Downstream effect

GH pulse + strong appetite stimulation; modest IGF-1 elevationBowers 2002

Strong GH pulse + IGF-1 elevation; cardio-protective effects in animal MI modelsGhigo 1997

Feedback intact?

—

Yes initially; tachyphylaxis with chronic useGhigo 1997

Origin

Synthetic hexapeptide; first-generation GHRP from Bowers groupBowers 1990

Synthetic hexapeptide His-D-2-Methyl-Trp-Ala-Trp-D-Phe-Lys-NH₂Smith 1996

Antibody development

—

02Dosage Protocols

Parameter

GHRP-6

Hexarelin

Standard dose

100–200 mcg per injectionBowers 1990

100–200 mcg per injectionSmith 1996

Frequency

1–3× per day

1–2× per day max (tachyphylaxis with chronic 3× daily)

Lower / starter dose

50 mcg per dose

Evidence basis

Phase 1 + clinical practiceBowers 1990

Phase 1 / Phase 2 trialsSmith 1996 Ghigo 1997

Duration

8–12 weeks on / 4 off

4–8 weeks on / 4–8 weeks off (tachyphylaxis mitigation)

Reconstitution

Bacteriostatic water

Timing

Pre-meal preferred for appetite support

Pre-sleep + fasted preferred

Half-life

~15 minMalagón 1999

~70 minSemenistaya 2010

04Side Effects & Safety

Parameter

GHRP-6

Hexarelin

Hunger

Pronounced — defining feature vs ipamorelin

Strong appetite increase via ghrelin agonism

Cortisol elevation

Mild

Modest at high dosesGhigo 1997

Prolactin elevation

Mild

Modest at high dosesGhigo 1997

Injection site reaction

Mild

—

Cancer risk

Contraindicated in active malignancy

Contraindicated in active malignancy (GH/IGF-1 axis)

Pregnancy / OB

Avoid

Tachyphylaxis

—

Receptor desensitisation with chronic dosingGhigo 1997

Cardiac effects

—

Direct cardio-tropic; potential benefit in MI but unstudied in humansGhigo 1997

IGF-1 elevation

—

Strong; monitor with chronic high-dose use

Absolute Contraindications

GHRP-6

·Active malignancy
·Pregnancy / breastfeeding

Hexarelin

·Active malignancy
·Pregnancy / breastfeeding
·Disrupted hypothalamic-pituitary axis

Relative Contraindications

GHRP-6

·Severe insulin resistance (appetite-driven caloric load)

Hexarelin

·Untreated diabetes
·Severe hyperprolactinemia

05Administration Protocol

Parameter

GHRP-6

Hexarelin

1. Reconstitution

Add 2 mL bacteriostatic water to 5 mg vial → 2.5 mg/mL.

Add 2 mL bacteriostatic water to 5 mg vial → 2.5 mg/mL = 250 mcg per 0.1 mL.

2. Injection site

SQ — abdomen. Rotate sites.

SQ — abdomen or thigh. Rotate sites.

3. Timing

Pre-meal for appetite support; pre-sleep for GH alignment.

Pre-sleep + fasted preferred. Cycle on/off to avoid tachyphylaxis.

4. Storage

Lyophilised: room temp. Reconstituted: refrigerate ≤30 days.

Lyophilised: room temp, light-protected. Reconstituted: refrigerate ≤30 days.

5. Needle

29–31G, 4–8 mm insulin syringe.

06Stack Synergy

GHRP-6

— no documented stacks

Hexarelin

+ CJC-1295 (no DAC)

Strong

View CJC-1295 (no DAC) →

Hexarelin (GHRP) + CJC-1295-no-DAC (GHRH analogue) is the higher-amplitude variant of the standard GHRH+GHRP stack. Hexarelin produces a stronger pulse than ipamorelin but with cortisol + prolactin signal — choose this stack for maximum GH amplitude when side-effect tolerance is acceptable. Cycle aggressively.

Hexarelin: 100 mcg SQ · pre-sleep
CJC-1295 (no DAC): 100 mcg SQ · same injection
Primary benefit: Maximum GH pulse amplitude (with side-effect signal)

Smith 1996 Teichman 2006