Side-by-side · Research reference
MGFvsMOTS-c
Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.
AAnimal-StrongHUMAN-REVIEWED14/55 cited
BAnimal-StrongHUMAN-REVIEWED16/68 cited
MGF
IGF-1Ec Splice Variant · Muscle-Specific
SQ · Research context only
MOTS-c
Mitokine · Mitochondria-Encoded
SQ · Variable · 2–3×/week
01Mechanism of Action
Parameter
MGF
MOTS-c
Primary target
Satellite cells (Pax7+) in skeletal muscleMoore 2018
Mitochondrial 12S rRNA sORF → folate-AICAR-AMPK axisLee 2015
Pathway
Mechanical stress → IGF-1Ec mRNA upregulation → Local E-domain peptide release → Satellite cell activation
Downstream effect
Satellite cell proliferation, myoblast differentiation, muscle fiber repair
Enhanced fatty acid oxidation, GLUT4-mediated glucose uptake, mitochondrial bioenergetics, anti-inflammationLee 2015
Origin
Alternative splicing of IGF-1 gene (exons 4-6) produces IGF-1Ec precursor; E-domain cleaved post-translationallyArmakolas 2016Vassilakos 2017
Endogenous 16-AA mitokine; mtDNA-encoded; declines with age; upregulated by exerciseReynolds 2021
Antibody development
—
—
02Dosage Protocols
Parameter
MGF
MOTS-c
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.
—
Evidence basis
Animal models + in vitro only
Animal + anecdotalLee 2015Reynolds 2021A first-in-human phase 1 study 2021
Phase 1a/1b CB4211 analog trial completed 2021; no native MOTS-c RCT published.
Standard dose
—
5–10 mg / weekLee 2015
Experimental, extrapolated from animal data. No human RCT-derived dose.
Frequency
—
2–3× per week
Short half-life may necessitate more frequent dosing for saturation.
Lower / starter dose
—
2.5–5 mg / week
Recommended due to limited human data.
Duration
—
4–12 weeks (experimental)
Optimal cycle length unknown.
Reconstitution
—
Bacteriostatic water, 1–2 mL
10 mg/mL at 1 mL.
Timing
—
Pre-workout or fasted state preferred
Activity-context amplifies AMPK response.
Half-life
—
Minutes to hours (estimated)
Systemically unstable; native MOTS-c PK in humans not fully characterised.
03Metabolic / Fat Loss Evidence
Parameter
MGF
MOTS-c
Primary fat target
—
Diet-induced / metabolic obesity; systemic fat utilization
Quantified reduction
—
Significant HFD fat gain ↓Lee 2015
Murine models, dose-dependent (5 & 15 mg/kg).
IGF-1 impact
—
No direct IGF-1 pathway; AMPK-mediated
Effect on lean mass
—
High dose significantly ↑ lean mass in mice
Triglycerides
—
AMPK-driven FA oxidation suggests TG benefit (not directly measured)
Effect reversibility
—
Unknown — no long-term follow-up data
Key publication
—
Lee Cell Metab 2015 · Reynolds Nat Commun 2021 · Kim Cell Metab 2018Lee 2015Reynolds 2021Kim 2018
04Side Effects & Safety
Parameter
MGF
MOTS-c
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
—
Injection site reaction
—
Mild irritation (reported)
Fluid retention / Edema
—
Not reported
Cardiovascular
—
Heart palpitations (anecdotal); cardiac hypertrophy reversed in diabetic rats
Cancer risk
—
Contradictory data — some models suggest pro-proliferative effects
CNS / Neurological
—
Insomnia, headache (anecdotal reports)
GI symptoms
—
Nausea, stomach discomfort (reported)
Antibody formation
—
No data (no long-term human trials)
Pregnancy / OB
—
Avoid — insufficient safety data
Evidence quality
—
Phase 1 analog (CB4211); preclinical; anecdotal humanA first-in-human phase 1 study 2021
Absolute Contraindications
MGF
- ·Active malignancy or history of IGF-1-sensitive cancers (prostate, colorectal, breast, osteosarcoma)
- ·No established therapeutic use — investigational only
MOTS-c
- ·Pregnancy / breastfeeding (insufficient data)
Relative Contraindications
MGF
- ·Family history of IGF-1-axis malignancies
- ·Use outside research setting
MOTS-c
- ·Active cancer or cancer predisposition
- ·AMPK pathway deficiency (efficacy nullified)
- ·Use with cancer-promoting medications (theoretical)
05Administration Protocol
Parameter
MGF
MOTS-c
1. No validated protocol
MGF (E-domain peptide) has no approved clinical protocol. All published data derive from animal models or in vitro experiments.
Add 1–2 mL bacteriostatic water. At 10 mg/vial, 1 mL gives 10 mg/mL concentration. Roll gently to dissolve.
2. Synthetic peptide form
Commercially available MGF corresponds to the 24-amino-acid human E-domain (hEc). Rodent E-domain (Eb) is structurally distinct and not interchangeable.
Subcutaneous — abdomen, thigh, or deltoid. Rotate sites to avoid lipohypertrophy. Pinch fat layer.
3. Animal delivery models
Rodent studies used peptide-eluting polymeric microstructures (cardiac) or direct intramuscular injection. Routes and doses non-translatable to humans.Peña 2015Shioura 2014
Pre-workout or fasted state preferred — metabolic context amplifies AMPK response. 2–3× per week.
4. WADA prohibition
MGF peptides prohibited in sport since 2005. Detection via LC-MS established for full-length MGF products.Thevis 2014
Lyophilised: room temp, protected from light. Reconstituted: refrigerate, use within 21–30 days. Short systemic stability.
5. Research context only
Any human use falls outside approved medical practice and regulatory frameworks. No safety or efficacy data exist.
27–31G insulin syringe. Short needle (4–6 mm) for SQ delivery. Clean technique mandatory.
06Stack Synergy
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
MOTS-c
+ Ipamorelin
ModerateMOTS-c activates AMPK/PGC-1α for mitochondrial efficiency and fatty acid oxidation; ipamorelin stimulates GH for anabolic recovery and sleep depth. Pathways are complementary — MOTS-c handles metabolic flexibility and glucose handling while ipamorelin drives recovery and body recomposition through GH. Theoretical synergy is high; clinical data is lacking.
- MOTS-c
- 5 mg SQ · pre-workout (2–3×/wk)
- Ipamorelin
- 200–300 mcg SQ · pre-sleep (daily)
- Primary benefit
- Metabolic flexibility + GH recovery + ROS reduction