Side-by-side · Research reference
IpamorelinvsMGF
Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.
APhase 1HUMAN-REVIEWED21/57 cited
BAnimal-StrongHUMAN-REVIEWED14/55 cited
Ipamorelin
Selective GHRP · Ghrelin Mimetic
SQ · Multiple sites · 1–3×/day
MGF
IGF-1Ec Splice Variant · Muscle-Specific
SQ · Research context only
01Mechanism of Action
Parameter
Ipamorelin
MGF
Primary target
Ghrelin receptor (GHS-R1a) on anterior pituitaryRaun 1998
Satellite cells (Pax7+) in skeletal muscleMoore 2018
Pathway
GHS-R1a binding → Gαq/11 → ↑intracellular Ca²⁺ → GH vesicle exocytosisRaun 1998Bowers 1991
Mechanical stress → IGF-1Ec mRNA upregulation → Local E-domain peptide release → Satellite cell activation
Downstream effect
GH pulse amplification, IGF-1 elevation, recovery and lipolytic effectsBowers 2002
Satellite cell proliferation, myoblast differentiation, muscle fiber repair
Origin
Pentapeptide H-Aib-His-D-2-Nal-D-Phe-Lys-NH₂; rationally designed for ghrelin-receptor selectivityRaun 1998
Alternative splicing of IGF-1 gene (exons 4-6) produces IGF-1Ec precursor; E-domain cleaved post-translationallyArmakolas 2016Vassilakos 2017
Antibody development
Not reported in short-term studies
—
02Dosage Protocols
Parameter
Ipamorelin
MGF
Standard dose
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
100 mcg per dose
—
Duration
8–12 weeks on / 4 weeks off (anecdotal)
GHS-R desensitisation reported with continuous dosing.
—
Reconstitution
Bacteriostatic water; typical 2 mL per 5 mg vial
—
Timing
Pre-sleep + fasted preferred; 30 min away from food
—
Synthetic peptide
—
24-amino-acid E-domain sequence
Corresponds to human IGF-1Ec exons 4-6 region.
Rodent cardiac model
—
200 μg/kg via peptide-eluting microstructures
Post-MI injection; improved ejection fraction by 8 weeks.
Acute delivery (mouse MI)
—
Single bolus within 12 hrs post-infarctionShioura 2014
Delayed decompensation; no human protocol established.
Human evidence
—
None — no published clinical trials
All dosing extrapolated from animal models.
Detection in doping
—
Full-length MGF detected via LC-MS in illicit productsThevis 2014
WADA-prohibited since 2005; no therapeutic indication.
04Side Effects & Safety
Parameter
Ipamorelin
MGF
Hunger
Mild appetite increase via ghrelin-receptor crosstalk
—
Injection site reaction
Mild irritation possible
—
GH excess (overdose)
Joint pain, edema, insulin resistance
—
IGF-1 elevation
Dose-dependent; monitor with chronic high-dose use
—
Cancer risk
Theoretical via GH/IGF-1 axis; contraindicated in active malignancy
—
Pregnancy / OB
Avoid
—
Human safety data
—
None — no clinical trials published
Theoretical IGF-1 axis risk
—
Chronic IGF-1Ec overexpression linked to cancer progression (prostate, colorectal, breast)
Tumor promotion
—
IGF-1Ec overexpressed in osteosarcoma, colorectal polyps with dysplasia, endometrial cancer
Antibody development
—
Unknown — no longitudinal human exposure data
Local injection reaction
—
Presumed similar to other peptides (erythema, induration) — no direct evidence
Dysregulated expression with age
—
Older adults (70+ yrs) show blunted IGF-1Ec response post-exercise vs youngMoore 2018
Absolute Contraindications
Ipamorelin
- ·Active malignancy or cancer history
- ·Pregnancy / breastfeeding
- ·Disrupted hypothalamic-pituitary axis
MGF
- ·Active malignancy or history of IGF-1-sensitive cancers (prostate, colorectal, breast, osteosarcoma)
- ·No established therapeutic use — investigational only
Relative Contraindications
Ipamorelin
- ·Untreated diabetes
- ·Severe insulin resistance
- ·Concurrent corticosteroid use (theoretical desensitisation)
MGF
- ·Family history of IGF-1-axis malignancies
- ·Use outside research setting
05Administration Protocol
Parameter
Ipamorelin
MGF
1. Reconstitution
Add 2 mL bacteriostatic water to 5 mg vial → 2.5 mg/mL. Roll gently. Solution should be clear.
MGF (E-domain peptide) has no approved clinical protocol. All published data derive from animal models or in vitro experiments.
2. Injection site
Subcutaneous, abdomen or thigh. Rotate sites. Pinch fat for shallow SQ delivery.
Commercially available MGF corresponds to the 24-amino-acid human E-domain (hEc). Rodent E-domain (Eb) is structurally distinct and not interchangeable.
3. Timing
Pre-sleep optimal — aligns with natural GH pulse. Some protocols add a morning fasted dose.
Rodent studies used peptide-eluting polymeric microstructures (cardiac) or direct intramuscular injection. Routes and doses non-translatable to humans.Peña 2015Shioura 2014
4. Storage
Lyophilised: room temp, protected from light. Reconstituted: refrigerate 2–8 °C, use within 30 days.
MGF peptides prohibited in sport since 2005. Detection via LC-MS established for full-length MGF products.Thevis 2014
5. Needle
29–31G, 4–8 mm insulin syringe.
Any human use falls outside approved medical practice and regulatory frameworks. No safety or efficacy data exist.
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
MGF
+ BPC-157
Multi-pathwayMGF activates satellite cells for muscle fiber repair; BPC-157 promotes angiogenesis, collagen synthesis, and tendon healing via distinct pathways (VEGF, FAK, integrin signaling). Theoretical synergy in post-injury contexts combines myogenic (MGF) and stromal (BPC-157) repair mechanisms. Both lack human validation.
- MGF
- No established dose
- BPC-157
- 250–500 mcg SQ near injury site
- Context
- Animal models only
- Primary benefit
- Theoretical multi-tissue repair (muscle + tendon/ligament)
+ TB-500
ModerateTB-500 (thymosin beta-4 fragment) enhances actin polymerization, cell migration, and angiogenesis—complementary to MGF satellite cell activation. Both upregulated post-injury; combined use presumed additive for muscle regeneration in preclinical models.
- MGF
- No established dose
- TB-500
- 2–5 mg SQ weekly
- Context
- Animal models only
- Primary benefit
- Satellite cell activation + enhanced migration/angiogenesis