Side-by-side · Research reference

GHRP-6vsIpamorelin

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 1Reviewed21/57 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

Ipamorelin

Selective GHRP · Ghrelin Mimetic

200–300 mcgPer doseRaun 1998

Phase 1Evidence levelRaun 1998 Sigalos 2018

~2 hrHalf-lifeRaun 1998

SQ · Multiple sites · 1–3×/day

01Mechanism of Action

Parameter

GHRP-6

Ipamorelin

Primary target

Ghrelin receptor (GHS-R1a)Bowers 1990

Ghrelin receptor (GHS-R1a) on anterior pituitaryRaun 1998

Pathway

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

GHS-R1a binding → Gαq/11 → ↑intracellular Ca²⁺ → GH vesicle exocytosisRaun 1998 Bowers 1991

Downstream effect

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

GH pulse amplification, IGF-1 elevation, recovery and lipolytic effectsBowers 2002

Feedback intact?

—

Yes — pulsatile pattern preserved; somatostatin feedback activeBowers 2002

Origin

Synthetic hexapeptide; first-generation GHRP from Bowers groupBowers 1990

Pentapeptide H-Aib-His-D-2-Nal-D-Phe-Lys-NH₂; rationally designed for ghrelin-receptor selectivityRaun 1998

Antibody development

—

Not reported in short-term studies

02Dosage Protocols

Parameter

GHRP-6

Ipamorelin

Standard dose

100–200 mcg per injectionBowers 1990

200–300 mcg per injectionRaun 1998

Anecdotal community range; clinical doses 1–3 mg IV in trials.

Frequency

1–3× per day

Once daily pre-sleep is most common; twice or thrice for advanced users.

Lower / starter dose

50 mcg per dose

100 mcg per dose

Evidence basis

Phase 1 + clinical practiceBowers 1990

Phase 1 + clinical practiceRaun 1998 Sigalos 2018

Duration

8–12 weeks on / 4 off

8–12 weeks on / 4 weeks off (anecdotal)

GHS-R desensitisation reported with continuous dosing.

Reconstitution

Bacteriostatic water

Bacteriostatic water; typical 2 mL per 5 mg vial

Timing

Pre-meal preferred for appetite support

Pre-sleep + fasted preferred; 30 min away from food

Half-life

~15 minMalagón 1999

~2 hoursRaun 1998

Longer than GHRP-6 (15 min); shorter than CJC-1295-DAC (~8 days).

04Side Effects & Safety

Parameter

GHRP-6

Ipamorelin

Hunger

Pronounced — defining feature vs ipamorelin

Mild appetite increase via ghrelin-receptor crosstalk

Cortisol elevation

Mild

Negligible vs other GHRPsRaun 1998

Prolactin elevation

Mild

NegligibleRaun 1998

Injection site reaction

Mild

Mild irritation possible

Cancer risk

Contraindicated in active malignancy

Theoretical via GH/IGF-1 axis; contraindicated in active malignancy

Pregnancy / OB

Avoid

GH excess (overdose)

—

Joint pain, edema, insulin resistance

IGF-1 elevation

—

Dose-dependent; monitor with chronic high-dose use

Absolute Contraindications

GHRP-6

·Active malignancy
·Pregnancy / breastfeeding

Ipamorelin

·Active malignancy or cancer history
·Pregnancy / breastfeeding
·Disrupted hypothalamic-pituitary axis

Relative Contraindications

GHRP-6

·Severe insulin resistance (appetite-driven caloric load)

Ipamorelin

·Untreated diabetes
·Severe insulin resistance
·Concurrent corticosteroid use (theoretical desensitisation)

05Administration Protocol

Parameter

GHRP-6

Ipamorelin

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. Roll gently. Solution should be clear.

2. Injection site

SQ — abdomen. Rotate sites.

Subcutaneous, abdomen or thigh. Rotate sites. Pinch fat for shallow SQ delivery.

3. Timing

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

Pre-sleep optimal — aligns with natural GH pulse. Some protocols add a morning fasted dose.

4. Storage

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

Lyophilised: room temp, protected from light. Reconstituted: refrigerate 2–8 °C, use within 30 days.

5. Needle

29–31G, 4–8 mm insulin syringe.

06Stack Synergy

GHRP-6

— no documented stacks

Ipamorelin

+ Tesamorelin

Strong

View Tesamorelin →

Ipamorelin (GHRP) + tesamorelin (GHRH analogue) is the textbook dual-axis GH stack. They activate two distinct pituitary receptors — the ghrelin receptor and the GHRH receptor — producing a synergistic GH pulse larger than either alone. Ipamorelin's selectivity (no cortisol/prolactin spike) makes it the ideal GHRP partner for long-term protocols.

Ipamorelin: 200–300 mcg SQ · pre-sleep
Tesamorelin: 2 mg SQ · same injection · pre-sleep
Primary benefit: Maximal GH pulsatility, fat loss, recovery, sleep depth

Raun 1998 Bowers 2002

+ CJC-1295 (no DAC)

Strong

View CJC-1295 (no DAC) →

CJC-1295 (no DAC) is a short-acting GHRH analogue. Combined with ipamorelin (GHRP), the pulse is amplified across both receptor systems with timing similar to native physiology. Without the DAC modification, the stack maintains sharp peaks rather than the sustained elevation seen with CJC-1295-DAC + ipamorelin.

Ipamorelin: 200–300 mcg SQ · pre-sleep
CJC-1295 (no DAC): 100 mcg SQ · same injection
Primary benefit: Pulsatile GH stimulation matching physiological pattern

Teichman 2006 Ionescu 2006