CalcMyPeptide
Healing & RecoveryAlso known as: Mechano Growth Factor, IGF-1Ec

MGF

MGF (Mechano Growth Factor), precisely known as the IGF-1Ec splice variant, is the raw, unadulterated "first responder" peptide generated endogenously the exact second a muscle fiber suffers mechanical overload (trauma). Because it completely lacks the protective PEGylation of its systemic variant, synthetic MGF possesses a brutally short half-life of roughly 5 to 7 minutes in plasma. Consequently, it must be injected intra-muscularly directly into a traumatized, lagging muscle group immediately post-training to force extreme localized hyperplasia.

Reviewed by CalcMyPeptide Editorial Team
Last updated: April 2026Evidence: Low2 peer-reviewed citations

Quick Stats

Half-Life~5-7 minutes (native)
Dose Range100-200 mcg per site
Frequency1× daily (post-training)
Vial Sizes2 mg, 5 mg
BioavailabilityLocal intramuscular injection only
Year Developed1996

Scientific Data

Molecular Formula
IGF-1Ec splice variant (24 amino acid C-terminal extension)
Molecular Weight
~2.4 kDa (E-peptide fragment)
CAS Number
PubChem ID
Developer
Geoffrey Goldspink, University College London

Mechanism of Action

MGF (Mechano Growth Factor, IGF-1Ec) is a splice variant of IGF-1 produced locally in damaged muscle tissue. When muscle fibers experience mechanical load and micro-damage, the IGF-1 gene is alternatively spliced to produce MGF instead of systemic IGF-1.

MGF activates satellite cells (muscle stem cells) precisely at the injury site, initiating the repair and hypertrophy process. Its extremely short half-life (~5-7 minutes) makes it a highly localized signal — it must be injected directly into or near the target muscle to be pharmacologically active. This same half-life also means it degrades before causing systemic effects.

Source: PMID: 12620066

Background & History

MGF (Mechano Growth Factor) is the native, non-PEGylated splice variant of IGF-1 generated after mechanical load or injury. It contains a unique 24-amino-acid E-domain that distinguishes it from systemic IGF-1 and specifically activates quiescent muscle satellite cells. The E-domain peptide has also been shown to have direct cardiac and neuroprotective effects independent of satellite cell activation. Its 2-minute half-life in blood means local injection near muscle is essential for activity.

Research Use Cases

  • Immediate post-injury satellite cell activation (inject locally)
  • Cardiac protection post-ischemia via independent E-domain mechanism
  • Neuroprotection in CNS injury models

Dosing Protocol

Typical Dose100-200 mcg per site
Frequency1× daily (post-training)
Half-Life~5-7 minutes
Common Vial Sizes2 mg, 5 mg

Dosing Protocols

Local Injection Protocol

Dose
100 - 200 mcg
Frequency
2-3x per week (IM or local SC)
Note: Must be injected locally at target muscle within minutes of reconstitution. Immediate post-workout timing.

Body-Weight Dosing Reference

Estimated doses extrapolated from the published research range of 100200 mcg/day (referenced to 70 kg / 154 lb). These are approximations — consult a qualified healthcare provider for personalised guidance.

WeightLowTargetHigh
120 lb(54 kg)77 mcg116 mcg154 mcg
140 lb(63 kg)90 mcg135 mcg180 mcg
160 lb(73 kg)104 mcg156 mcg209 mcg
180 lb(82 kg)117 mcg176 mcg234 mcg
200 lb(91 kg)130 mcg195 mcg260 mcg
220 lb(100 kg)143 mcg214 mcg286 mcg
250 lb(113 kg)161 mcg242 mcg323 mcg

💉 For exact syringe units based on your vial concentration, use the MGF Reconstitution Calculator →

Administration

Route
Intramuscular or local subcutaneous injection
Timing
Immediately post-workout, injected at target muscle.
Fasting Required?
No — food timing not critical

Expected Timeline

Immediately post-injection
Local satellite cell activation at the injection site.
Week 2-6
Enhanced local muscle repair. More complete hypertrophy response in targeted muscles.

Who Is It For?

Targeted Muscle Repair

Low

The most targeted muscle growth factor. Works only locally — ideal for lagging muscles or injury recovery.

Reconstitution Example

Vial
2 mg
Water
2 mL
Concentration
1 mg/mL
Per Unit (100u syringe)
10 mcg
Dose of 100 mcg = 10 units on a 100-unit insulin syringe

Safety & Considerations

Research peptide. Must be injected locally (intramuscular or subcutaneous near target). Very short half-life means systemic injection is ineffective — use immediately after reconstitution. Do not freeze after reconstitution.

Regulatory & Legal Status

FDA Status (US)
Research Only
WADA Status (2026)
Not Listed

Not currently on the WADA 2026 Prohibited List. Policies may change — verify before competition.

Classification

Research Chemical

US Compounding: Not eligible / not available

⚠️ This information is for educational purposes only and may not reflect the most current regulatory updates. Always verify with official FDA, WADA, and jurisdiction-specific sources before use.

Interactions & Contraindications

Must be injected directly into or near target muscle tissue due to 2-minute serum half-life. No systemic activity from non-local injection. As an IGF-1 family peptide: contraindicated with active cancer. Localized hypoglycemia risk at injection site is minimal.

Synergies & Common Stacks

MGF provides immediate local satellite cell activation (short burst); PEG-MGF extends this signal for 48-72 hours. Sequential protocol for maximum muscle repair.

MGF activates satellite cells; IGF-1 LR3 drives them to proliferate and differentiate. Complete myogenic cascade activation.

Dosing Quick Reference

MGF— Dosing Guide
Dose Range
100-200 mcg per site
Half-Life
~5-7 minutes
Frequency
1× daily (post-training)
Route
Subcutaneous
2 mg vial5 mg vial
💧 2 mL BAC water📐 1 mg/mL concentration💉 10 mcg/unit (100u syringe)
Healing & Recoverycalcmypeptide.com

Frequently Asked Questions

Why must MGF be injected locally?
MGF has a ~5-7 minute half-life — it is degraded too quickly to provide systemic effects. Local injection delivers it directly to satellite cells at the repair site. For systemic effects, use PEG-MGF instead.
When should I inject MGF?
Immediately post-training, injected intramuscularly or subcutaneously near the target muscle. This mimics the natural MGF response to mechanical muscle damage.

References

  1. Goldspink G "Mechano growth factor: a tissue specific anabolic growth factor".” Biochemical Society Transactions (2002). PMID: 12196225

📚 Related Articles

Looking for a trusted source? See our recommended suppliers →

Independently tested · COA-verified · Save 10% with our exclusive code