Side-by-side · Research reference

GHRP-6vsMGF

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

APhase 1HUMAN-REVIEWED10/36 cited

BAnimal-StrongHUMAN-REVIEWED14/55 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

MGF

IGF-1Ec Splice Variant · Muscle-Specific

IGF-1EcSplice variantArmakolas 2016

24-AASynthetic E-domain

Animal onlyHuman evidence

SQ · Research context only

01Mechanism of Action

Parameter

GHRP-6

MGF

Primary target

Ghrelin receptor (GHS-R1a)Bowers 1990

Satellite cells (Pax7+) in skeletal muscleMoore 2018

Pathway

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

Mechanical stress → IGF-1Ec mRNA upregulation → Local E-domain peptide release → Satellite cell activation

Downstream effect

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

Satellite cell proliferation, myoblast differentiation, muscle fiber repair

Feedback intact?

—

Origin

Synthetic hexapeptide; first-generation GHRP from Bowers groupBowers 1990

Alternative splicing of IGF-1 gene (exons 4-6) produces IGF-1Ec precursor; E-domain cleaved post-translationallyArmakolas 2016 Vassilakos 2017

Antibody development

—

02Dosage Protocols

Parameter

GHRP-6

MGF

Standard dose

100–200 mcg per injectionBowers 1990

—

Frequency

1–3× per day

—

Lower / starter dose

50 mcg per dose

—

Evidence basis

Phase 1 + clinical practiceBowers 1990

Animal models + in vitro only

Duration

8–12 weeks on / 4 off

—

Reconstitution

Bacteriostatic water

—

Timing

Pre-meal preferred for appetite support

—

Half-life

~15 minMalagón 1999

—

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

GHRP-6

MGF

Hunger

Pronounced — defining feature vs ipamorelin

—

Cortisol elevation

Mild

—

Prolactin elevation

Mild

—

Injection site reaction

Mild

—

Cancer risk

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

GHRP-6

·Active malignancy
·Pregnancy / breastfeeding

MGF

·Active malignancy or history of IGF-1-sensitive cancers (prostate, colorectal, breast, osteosarcoma)
·No established therapeutic use — investigational only

Relative Contraindications

GHRP-6

·Severe insulin resistance (appetite-driven caloric load)

MGF

·Family history of IGF-1-axis malignancies
·Use outside research setting

05Administration Protocol

Parameter

GHRP-6

MGF

1. Reconstitution

Add 2 mL bacteriostatic water to 5 mg vial → 2.5 mg/mL.

MGF (E-domain peptide) has no approved clinical protocol. All published data derive from animal models or in vitro experiments.

2. Injection site

SQ — abdomen. Rotate sites.

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

Rodent studies used peptide-eluting polymeric microstructures (cardiac) or direct intramuscular injection. Routes and doses non-translatable to humans.Peña 2015 Shioura 2014

4. Storage

Lyophilised: room temp. Reconstituted: refrigerate ≤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

GHRP-6

— no documented stacks

MGF

+ BPC-157

Multi-pathway

View BPC-157 →

MGF 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

Moderate

View TB-500 →

TB-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