Side-by-side · Research reference

MGFvsMT-1

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

BFDA-ApprovedHUMAN-REVIEWED9/51 cited

MGF

IGF-1Ec Splice Variant · Muscle-Specific

IGF-1EcSplice variantArmakolas 2016

24-AASynthetic E-domain

Animal onlyHuman evidence

SQ · Research context only

MT-1

α-MSH Analogue · FDA-Approved

16 mgImplant dose

13 AAPeptide lengthChawathe 2026

2019FDA approval

SQ Implant · 60-Day Release

01Mechanism of Action

Parameter

MGF

MT-1

Primary target

Satellite cells (Pax7+) in skeletal muscleMoore 2018

Melanocortin-1 receptor (MC1R) on melanocytesLangan 2010

Pathway

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

α-MSH analogue → MC1R activation → cAMP elevation → MITF transcription → eumelanin synthesis

Downstream effect

Satellite cell proliferation, myoblast differentiation, muscle fiber repair

Increased melanogenesis, photoprotection, reduced UV sensitivityLangan 2010

Feedback intact?

—

Yes — exogenous MC1R agonism does not suppress endogenous α-MSH production

Origin

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

Synthetic 13-AA peptidomimetic with norleucine (position 4) and D-phenylalanine (position 7) substitutions for metabolic stabilityChawathe 2026

Antibody development

—

02Dosage Protocols

Parameter

MGF

MT-1

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

Phase 3 RCT / FDA-approved orphan drug

Standard dose

—

16 mg subcutaneous implant

FDA-approved formulation (Scenesse).

Frequency

—

Every 60 days

Sustained release implant — no daily administration required.

Indication

—

Erythropoietic protoporphyria (EPP)

Narrow FDA approval — not licensed for cosmetic tanning.

Duration

—

Seasonal use (spring–autumn typical)

Aligned with peak UV exposure months.

Route

—

Subcutaneous implant — upper arm or abdomen

Stability

—

Norleucine/D-Phe substitutions enhance peptidase resistance

Modified structure vs endogenous α-MSH (Met⁴, L-Phe⁷).

04Side Effects & Safety

Parameter

MGF

MT-1

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

—

Nausea

—

Common (>10%) — mild, transient

Implant site reaction

—

Erythema, bruising, tenderness at insertion site

Hyperpigmentation

—

Generalised tanning (therapeutic effect), darkening of freckles/neviLangan 2010 Habbema 2017

Expected melanogenic response — complicates pigmented lesion surveillance.

Melanocytic changes

—

Rapid pigmentation of existing nevi; new melanocytic lesions reported with unregulated useHabbema 2017

Requires dermatologic monitoring; theoretical melanoma concern with chronic stimulation.

Headache

—

Occasional (MC1R-independent melanocortin effects)

Photosensitivity (paradoxical)

—

Rare phototoxic reactions despite melanin increase

Contamination risk (unregulated)

—

Impurity, infection, blood-borne virus transmission from illicit melanotan productsLangan 2010 Habbema 2017

Applies to internet/gym-sourced 'melanotan' — not FDA-approved Scenesse.

Absolute Contraindications

MGF

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

MT-1

·Hypersensitivity to afamelanotide or excipients
·Hepatic impairment (no safety data)
·Renal impairment (no safety data)

Relative Contraindications

MGF

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

MT-1

·History of melanoma or atypical nevi (melanocortin receptor stimulation concern)Habbema 2017
·Pregnancy/lactation (insufficient data)
·Photosensitive dermatoses (other than EPP)

05Administration Protocol

Parameter

MGF

MT-1

1. No validated protocol

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

Performed by trained healthcare provider. Sterile technique. Small incision in upper arm (triceps) or lower abdomen using trocar. 16 mg rod (4 mm × 1.5 cm) inserted subcutaneously.

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.

Pressure applied post-insertion. Sterile dressing × 24 hrs. Avoid strenuous activity for 24–48 hrs to prevent extrusion.

3. Animal delivery models

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

Slow biodegradable polymer matrix releases afamelanotide over 60 days, maintaining therapeutic plasma levels without daily dosing.

4. WADA prohibition

MGF peptides prohibited in sport since 2005. Detection via LC-MS established for full-length MGF products.Thevis 2014

New implant every 60 days during high UV season (spring–autumn in temperate climates). Rotate implant sites to avoid scarring.

5. Research context only

Any human use falls outside approved medical practice and regulatory frameworks. No safety or efficacy data exist.

Baseline and periodic dermatologic exams to document pigmented lesions. Patient education on self-examination for new/changing nevi.

06Stack Synergy

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

MT-1

— no documented stacks