Skip to content
Specimen Atlas of Research Peptides30 plates · MIT
PeptidesDBan atlas
Side-by-side · Research reference

HexarelinvsSermorelin

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 3Reviewed14/43 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
Sermorelin
GHRH 1-29 fragment · Short-acting
100–500 mcgPer doseMolteno 2013
Phase 3Evidence levelWalker 1994Molteno 2013
~12 minHalf-lifeMolteno 2013
SQ · Pre-sleep · 1×/day

01Mechanism of Action

Parameter
Hexarelin
Sermorelin
Primary target
Ghrelin receptor (GHS-R1a) + cardiac CD36Smith 1996Ghigo 1997
Pituitary GHRH receptorWalker 1994
Pathway
GHS-R1a → Gαq → Ca²⁺ → GH release. CD36 engagement → direct cardio-tropic actionGhigo 1997
GHRH-R → Gαs → cAMP → PKA → GH vesicle exocytosisWalker 1994
Downstream effect
Strong GH pulse + IGF-1 elevation; cardio-protective effects in animal MI modelsGhigo 1997
Pulsatile GH release; subsequent IGF-1 elevationMolteno 2013
Feedback intact?
Yes initially; tachyphylaxis with chronic useGhigo 1997
Yes — short pulse preserves feedback
Origin
Synthetic hexapeptide His-D-2-Methyl-Trp-Ala-Trp-D-Phe-Lys-NH₂Smith 1996
Unmodified active 29-AA fragment of human GHRH (1-44)Walker 1994
Antibody development
—
—

02Dosage Protocols

Parameter
Hexarelin
Sermorelin
Standard dose
100–200 mcg per injectionSmith 1996
100–500 mcg per injectionMolteno 2013
Frequency
1–2× per day max (tachyphylaxis with chronic 3× daily)
Once daily, pre-sleep
Lower / starter dose
50 mcg per dose
100 mcg per dose
Evidence basis
Phase 1 / Phase 2 trialsSmith 1996Ghigo 1997
Phase 3 (Geref pediatric); clinical practiceWalker 1994Molteno 2013
Duration
4–8 weeks on / 4–8 weeks off (tachyphylaxis mitigation)
8–12 weeks per cycle
Reconstitution
Bacteriostatic water
Bacteriostatic water
Timing
Pre-sleep + fasted preferred
Pre-sleep, fasted preferred
Half-life
~70 minSemenistaya 2010
~12 min (plasma)Molteno 2013
Shorter than tesamorelin (~26 min) — simpler GHRH analogue.

04Side Effects & Safety

Parameter
Hexarelin
Sermorelin
Cortisol elevation
Modest at high dosesGhigo 1997
—
Prolactin elevation
Modest at high dosesGhigo 1997
—
Hunger
Strong appetite increase via ghrelin agonism
—
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
Modest at standard doses
Cancer risk
Contraindicated in active malignancy (GH/IGF-1 axis)
Contraindicated in active malignancy (GH/IGF-1 axis)
Pregnancy / OB
Avoid
Avoid
Injection site reaction
—
Mild erythema, transient pain
Flushing / headache
—
Common transient effect
Glucose handling
—
Generally neutral
Absolute Contraindications
Hexarelin
  • ·Active malignancy
  • ·Pregnancy / breastfeeding
  • ·Disrupted hypothalamic-pituitary axis
Sermorelin
  • ·Active malignancy
  • ·Pregnancy / breastfeeding
  • ·Disrupted hypothalamic-pituitary axis
Relative Contraindications
Hexarelin
  • ·Untreated diabetes
  • ·Severe hyperprolactinemia
Sermorelin
  • ·Untreated diabetes

05Administration Protocol

Parameter
Hexarelin
Sermorelin
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 = 250 mcg per 0.1 mL.
2. Injection site
SQ — abdomen or thigh. Rotate sites.
SQ — abdomen or thigh. Rotate sites.
3. Timing
Pre-sleep + fasted preferred. Cycle on/off to avoid tachyphylaxis.
Pre-sleep, fasted.
4. Storage
Lyophilised: room temp, light-protected. Reconstituted: refrigerate ≤30 days.
Lyophilised: room temp, light-protected. Reconstituted: refrigerate ≤30 days.
5. Needle
29–31G, 4–8 mm insulin syringe.
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 1996Teichman 2006
Sermorelin
+ Ipamorelin
Strong
View Ipamorelin →

Sermorelin (GHRH analogue) and ipamorelin (selective GHRP) form the prototypical GHRH+GHRP dual-axis stack at the lowest cost. Both peak within 30 min and produce a sharp physiological GH pulse without cortisol/prolactin elevation.

Sermorelin
200–300 mcg SQ · pre-sleep
Ipamorelin
200–300 mcg SQ · same injection
Primary benefit
Pulsatile GH stimulation, recovery, body composition
Raun 1998Walker 1994