Overview
MGF is a growth hormone-related peptide. Splice variant of IGF-1 (IGF-1Ec isoform).
With a half-life of ~6 minutes, MGF requires daily administration in most observed protocols. Administered via IM and SubQ injection, it has a bioavailability of approximately 70% via its primary route.
Extremely short half-life (~5–7 minutes) due to rapid proteolytic degradation. PEGylated variants extend circulating duration. One-compartment model.
Mechanism of Action
MGF's pharmacological activity involves the following key pathways:
Growth Factor Signaling
MGF binds to IGF-1 receptors, activating downstream signaling cascades involved in cell growth and tissue repair.
Dosing Protocols
The following protocols represent commonly observed dosing patterns. These are observational summaries, not recommendations.
Dose
100 mcg/day
Route
Intramuscular
Frequency
2-3 times daily
Duration
4-12 weeks
Dose
300 mcg/day
Route
Intramuscular
Frequency
2-3 times daily
Duration
4-12 weeks
Reconstitution Steps
MGF is supplied as a lyophilized (freeze-dried) powder and requires reconstitution before use. Common vial sizes: 2 mg, 5 mg.
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1
Prepare Your Workspace
Gather the MGF vial, bacteriostatic water, alcohol swabs, and an insulin syringe. Ensure a clean, well-lit work surface.
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2
Swab Vial Tops
Clean the rubber stoppers of both the MGF and bacteriostatic water vials with alcohol swabs. Allow to air dry completely before proceeding.
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3
Draw Bacteriostatic Water
Using an insulin syringe, draw 1 mL of bacteriostatic water for a 2 mg vial. This produces a concentration of 2,000 mcg/mL for straightforward dosing math.
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4
Add Water to Peptide Vial
Insert the needle and release the bacteriostatic water slowly down the inner wall of the MGF vial. Avoid directing the stream onto the lyophilized powder cake.
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5
Dissolve Gently
Let the vial sit undisturbed for 1–2 minutes, then roll gently between your palms until fully dissolved. Never shake the vial, as MGF is a fragile peptide susceptible to degradation from agitation.
Quick Reconstitution Math
2 mg vial + 1 mL bacteriostatic water = 2,000 mcg/mL. For a 200 mcg dose, draw 10 units (0.10 mL) on a U-100 insulin syringe. Use the Milligram reconstitution calculator for custom vial sizes.
Store lyophilized powder at -20°C. After reconstitution, refrigerate at 2–8°C and use within 5–10 days. MGF degrades faster than most peptides once in solution due to its small size and instability.
Frequently Asked Questions
What is MGF and how does it relate to IGF-1?
MGF (Mechano Growth Factor) is a splice variant of IGF-1, also designated IGF-1Ec. It is naturally produced in muscle tissue in response to mechanical overload such as resistance training. Unlike systemic IGF-1 which is released by the liver, MGF acts locally at the site of muscle damage to initiate repair by activating satellite cells – the resident stem cells of skeletal muscle.
What is the half-life of MGF and why is it so short?
Native MGF has an extremely short half-life of approximately 5–7 minutes due to rapid enzymatic degradation in the bloodstream. This short duration limits its systemic exposure but reflects its natural role as a locally-acting repair signal released directly at the site of muscle damage. PEGylated forms (PEG-MGF) extend the half-life to several days, but the native form requires precise timing around training.
How does MGF activate satellite cells for muscle repair?
MGF acts through its unique C-terminal E-domain peptide, which interacts with receptors on satellite cells independently of the standard IGF-1 receptor pathway. This triggers satellite cell proliferation and fusion with existing muscle fibers – a process essential for both muscle repair after damage and long-term hypertrophy. The effect is highly localized, meaning the peptide primarily influences tissue near the injection site.
When is the best time to administer MGF relative to training?
Due to its very short half-life, MGF is most commonly administered within 30 minutes of completing resistance training to coincide with the body's natural MGF release window. This timing synchronizes exogenous MGF with the endogenous repair cascade triggered by mechanical muscle damage. Administration on rest days is less commonly observed with native MGF.
What is the difference between MGF and PEG-MGF?
Native MGF has a half-life of approximately 5–7 minutes, while PEG-MGF (PEGylated Mechano Growth Factor) has a polyethylene glycol chain attached that extends the half-life to roughly 48–72 hours. PEG-MGF allows for less frequent dosing (2–3 times per week) and broader systemic distribution. Native MGF is preferred when site-specific, immediate post-workout signaling is the goal.
Can MGF be combined with IGF-1 LR3?
MGF and IGF-1 LR3 are sometimes used in alternating protocols rather than simultaneously, because their mechanisms partially overlap. A common approach involves using MGF immediately post-workout to initiate satellite cell activation, then switching to IGF-1 LR3 on non-training days to sustain anabolic signaling. Using both at the same time may lead to receptor competition and reduced efficiency of each compound.