Side-by-side · Research reference

HexarelinvsIpamorelin

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

APhase 1Reviewed19/45 cited

BPhase 1Reviewed21/57 cited

Hexarelin

Hexapeptide GHRP · Cardio-tropic

100–200 mcgPer doseSmith 1996

Phase 1Evidence levelGhigo 1997

~70 minHalf-lifeSemenistaya 2010

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

Hexarelin

Ipamorelin

Primary target

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

Ghrelin receptor (GHS-R1a) on anterior pituitaryRaun 1998

Pathway

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

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

Downstream effect

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

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

Feedback intact?

Yes initially; tachyphylaxis with chronic useGhigo 1997

Yes — pulsatile pattern preserved; somatostatin feedback activeBowers 2002

Origin

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

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

Hexarelin

Ipamorelin

Standard dose

100–200 mcg per injectionSmith 1996

200–300 mcg per injectionRaun 1998

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

Frequency

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

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 / Phase 2 trialsSmith 1996 Ghigo 1997

Phase 1 + clinical practiceRaun 1998 Sigalos 2018

Duration

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

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-sleep + fasted preferred

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

Half-life

~70 minSemenistaya 2010

~2 hoursRaun 1998

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

04Side Effects & Safety

Parameter

Hexarelin

Ipamorelin

Cortisol elevation

Modest at high dosesGhigo 1997

Negligible vs other GHRPsRaun 1998

Prolactin elevation

Modest at high dosesGhigo 1997

NegligibleRaun 1998

Hunger

Strong appetite increase via ghrelin agonism

Mild appetite increase via ghrelin-receptor crosstalk

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

Dose-dependent; monitor with chronic high-dose use

Cancer risk

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

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

Pregnancy / OB

Avoid

Injection site reaction

—

Mild irritation possible

GH excess (overdose)

—

Joint pain, edema, insulin resistance

Absolute Contraindications

Hexarelin

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

Ipamorelin

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

Relative Contraindications

Hexarelin

·Untreated diabetes
·Severe hyperprolactinemia

Ipamorelin

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

05Administration Protocol

Parameter

Hexarelin

Ipamorelin

1. Reconstitution

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

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

3. Timing

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

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

4. Storage

Lyophilised: room temp, light-protected. 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

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

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