Growth Hormone · 2mg × 10 vials
IGF-1 LR3 is a systemic "grow everything that has an IGF receptor" signal; MGF is the targeted "you just trained, activate the repair stem cells in this muscle" signal.
MGF (Mechano Growth Factor) is not a separate peptide invented in a lab. It is the IGF-1Ec splice variant the body itself produces in skeletal muscle in response to mechanical loading (resistance training, eccentric overload, micro-trauma). The IGF-1 gene gets alternatively spliced after damage, swapping in a unique 24-amino-acid C-terminal "E domain" that gives MGF a fundamentally different job from systemic IGF-1: instead of broad anabolic signaling everywhere, MGF acts locally to kick quiescent satellite cells (muscle stem cells living between the sarcolemma and the basal lamina) out of the G0 phase and into proliferation. Those activated satellite cells then fuse into damaged fibers, donating their nuclei and physically enlarging the muscle. Goldspink's lab at UCL (Hill & Goldspink, J Physiology 2003) was the first to identify this splice event and link it to satellite cell activation post-overload. The 24-aa E-peptide appears to have biological activity independent of the mature IGF-1 portion (it works upstream, driving myoblast proliferation before differentiation is triggered), which is why exogenous MGF behaves differently from exogenous IGF-1 LR3 even though they share an IGF backbone. Translation in plain language: IGF-1 LR3 is a systemic "grow everything that has an IGF receptor" signal; MGF is the targeted "you just trained, activate the repair stem cells in this muscle" signal. The catch is that native MGF has a half-life under 10 minutes (some sources say 5-7 min), so it has to be injected immediately post-workout into the trained muscle to do its job. PEG-MGF (pegylated MGF) bolts a polyethylene glycol chain onto the molecule, which protects it from proteolysis and pushes the half-life to roughly 48-72 hours, allowing 2-3x weekly subQ dosing instead of immediate-post-workout local IM pulses.
Typical dose ranges by experience level - educational reference. Message us and we tailor it to you.
Beginner reads are subtle. The signal to watch for is pump quality in the trained muscle the day-of and day-after, plus accelerated soreness resolution. Hypertrophy reads at this dose are not dramatic; MGF works at the satellite cell level, results compound over multiple cycles. Pair with a hypertrophy-focused training block (8-12 rep range, hard eccentrics, moderate volume) for the cleanest signal. If a researcher is not actively training, MGF will do effectively nothing for them.
This is the band where the satellite-cell-driven fullness becomes visible. Users frequently describe the trained muscle "filling out" rather than just pumping up, especially weeks 3-6. Pair with a hypertrophy block, not a strength block. Most intermediate users stack MGF alongside IGF-1 LR3 (LR3 daily systemic, MGF post-workout local) for the canonical IGF stack. PEG-MGF is the more practical option for researchers who can't or don't want to inject IM into trained muscles every session.
400 mcg per injection is the practical ceiling. The dose-response curve is shallow above this and side effect frequency rises (hypoglycemia, headache, localized swelling at injection site). Advanced users almost always run MGF inside a larger GH-axis stack (HGH or CJC+Ipa + IGF-1 LR3 + MGF) and report the MGF arm contributes specifically to the "trained muscle fullness" rather than systemic recomp. AAS users (bulk cycles with test/EQ/deca) layer MGF on top to amplify satellite cell recruitment during a high-volume hypertrophy block; this is the niche where MGF moves from "subtle add" to "noticeable contribution."
Straight talk - what people actually report, and what the studies measured.
Peer-reviewed studies and clinical guidelines - tap any to read the source.
](https://pmc.ncbi.nlm.nih.gov/articles/PMC3795771/) - foundational MGF biology
Read study ↗PubMedMechano Growth Factor promotes proliferation and inhibits differentiation of porcine satellite cells, Springer 2012Read study ↗PubMedFrontiers in Endocrinology - Mechano Growth Factor: important cog or loose screw in repair machinery (2012)](https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2012.00131/full)
Read study ↗PubMedMechano-growth factor, IGF-1 splice variant, promotes neurogenesis in aging mouse brain (PMID 28683812)](https://pubmed.ncbi.nlm.nih.gov/28683812/)
Read study ↗PubMedMechano-growth factor rescues motoneurons and improves muscle function in SOD1G93A ALS mice, ScienceDirectRead study ↗Aggregated sentiment from public forums & socials - real-world reports, not individual endorsements.
Pump quality in the trained muscle: the most-reported sensation, often described as a "permanent pump" lasting hours to days in the worked muscle group
Tingling sensation immediately post-injection: full-body or localized flush/tingle starting within minutes of injection, usually resolves within 30-60 min. Common enough that users expect it.
Localized swelling at IM injection site: more common with native MGF than PEG-MGF, usually mild, resolves within 24-48 hr
Hypoglycemia: less common than with IGF-1 LR3 at equivalent doses but possible, especially at 400+ mcg PEG-MGF stacked with other IGF compounds. Managed with pre-injection carb meal.
Headache: occasionally reported, especially in first week
Fatigue / "blah" feeling: occasional, more common in first cycle, generally resolves by week 2
Route: IM into the trained muscle for native MGF (timing-critical, immediate post-workout); SubQ for PEG-MGF (timing flexible)
Storage: refrigerated, ~10-14 days post-reconstitution (MGF is less stable than the GLP-1s; use sooner rather than later, freeze pre-recon vials for long storage)
Notes: Same hypoglycemia rule as IGF-1 LR3 applies at higher doses (especially PEG-MGF stacked with other IGF-receptor compounds): eat a carb meal 15-30 min pre-injection if dosing 400+ mcg, particularly if training fasted. Slow-wall reconstitution (run BAC down the side of the vial over 20-30 seconds), never shake, swirl gently. Native MGF must be drawn into the syringe and injected within minutes of reconstitution at the workout site for the timing to matter; this is why most researchers reconstitute one vial per session rather than batching ahead.