Side-by-side · Research reference
IpamorelinvsSermorelin
Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.
APhase 1Reviewed21/57 cited
BPhase 3Reviewed14/43 cited
Ipamorelin
Selective GHRP · Ghrelin Mimetic
SQ · Multiple sites · 1–3×/day
Sermorelin
GHRH 1-29 fragment · Short-acting
SQ · Pre-sleep · 1×/day
01Mechanism of Action
Parameter
Ipamorelin
Sermorelin
Primary target
Ghrelin receptor (GHS-R1a) on anterior pituitaryRaun 1998
Pituitary GHRH receptorWalker 1994
Pathway
GHS-R1a binding → Gαq/11 → ↑intracellular Ca²⁺ → GH vesicle exocytosisRaun 1998Bowers 1991
GHRH-R → Gαs → cAMP → PKA → GH vesicle exocytosisWalker 1994
Downstream effect
GH pulse amplification, IGF-1 elevation, recovery and lipolytic effectsBowers 2002
Pulsatile GH release; subsequent IGF-1 elevationMolteno 2013
Feedback intact?
Yes — pulsatile pattern preserved; somatostatin feedback activeBowers 2002
Yes — short pulse preserves feedback
Origin
Pentapeptide H-Aib-His-D-2-Nal-D-Phe-Lys-NH₂; rationally designed for ghrelin-receptor selectivityRaun 1998
Unmodified active 29-AA fragment of human GHRH (1-44)Walker 1994
Antibody development
Not reported in short-term studies
—
02Dosage Protocols
Parameter
Ipamorelin
Sermorelin
Standard dose
200–300 mcg per injectionRaun 1998
Anecdotal community range; clinical doses 1–3 mg IV in trials.
100–500 mcg per injectionMolteno 2013
Frequency
1–3× per day
Once daily pre-sleep is most common; twice or thrice for advanced users.
Once daily, pre-sleep
Lower / starter dose
100 mcg per dose
100 mcg per dose
Evidence basis
Phase 1 + clinical practiceRaun 1998Sigalos 2018
Phase 3 (Geref pediatric); clinical practiceWalker 1994Molteno 2013
Duration
8–12 weeks on / 4 weeks off (anecdotal)
GHS-R desensitisation reported with continuous dosing.
8–12 weeks per cycle
Reconstitution
Bacteriostatic water; typical 2 mL per 5 mg vial
Bacteriostatic water
Timing
Pre-sleep + fasted preferred; 30 min away from food
Pre-sleep, fasted preferred
Half-life
~2 hoursRaun 1998
Longer than GHRP-6 (15 min); shorter than CJC-1295-DAC (~8 days).
~12 min (plasma)Molteno 2013
Shorter than tesamorelin (~26 min) — simpler GHRH analogue.
04Side Effects & Safety
Parameter
Ipamorelin
Sermorelin
Hunger
Mild appetite increase via ghrelin-receptor crosstalk
—
Injection site reaction
Mild irritation possible
Mild erythema, transient pain
GH excess (overdose)
Joint pain, edema, insulin resistance
—
IGF-1 elevation
Dose-dependent; monitor with chronic high-dose use
Modest at standard doses
Cancer risk
Theoretical via GH/IGF-1 axis; contraindicated in active malignancy
Contraindicated in active malignancy (GH/IGF-1 axis)
Pregnancy / OB
Avoid
Avoid
Flushing / headache
—
Common transient effect
Glucose handling
—
Generally neutral
Absolute Contraindications
Ipamorelin
- ·Active malignancy or cancer history
- ·Pregnancy / breastfeeding
- ·Disrupted hypothalamic-pituitary axis
Sermorelin
- ·Active malignancy
- ·Pregnancy / breastfeeding
- ·Disrupted hypothalamic-pituitary axis
Relative Contraindications
Ipamorelin
- ·Untreated diabetes
- ·Severe insulin resistance
- ·Concurrent corticosteroid use (theoretical desensitisation)
Sermorelin
- ·Untreated diabetes
05Administration Protocol
Parameter
Ipamorelin
Sermorelin
1. Reconstitution
Add 2 mL bacteriostatic water to 5 mg vial → 2.5 mg/mL. Roll gently. Solution should be clear.
Add 2 mL bacteriostatic water to 5 mg vial → 2.5 mg/mL = 250 mcg per 0.1 mL.
2. Injection site
Subcutaneous, abdomen or thigh. Rotate sites. Pinch fat for shallow SQ delivery.
SQ — abdomen or thigh. Rotate sites.
3. Timing
Pre-sleep optimal — aligns with natural GH pulse. Some protocols add a morning fasted dose.
Pre-sleep, fasted.
4. Storage
Lyophilised: room temp, protected from light. Reconstituted: refrigerate 2–8 °C, use within 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
Ipamorelin
+ Tesamorelin
StrongIpamorelin (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
+ CJC-1295 (no DAC)
StrongCJC-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
Sermorelin
+ Ipamorelin
StrongSermorelin (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