Peptide Comparison
IGF-1 LR3vsPEG-MGF
A supercharged version of your body's own growth factor that stays active 2-3 times longer than regular IGF-1, making it a powerhouse for muscle growth, recovery, and cellular regeneration.
A supercharged version of your muscle's natural repair signal—PEGylated Mechano Growth Factor stays active for days instead of minutes, waking up dormant stem cells to rebuild and strengthen damaged muscle tissue.
At a Glance
Quick
comparison
Dose Range
IGF-1 LR3
20–100 mcg
PEG-MGF
100–200 mcg
Frequency
IGF-1 LR3
Once daily
PEG-MGF
Twice weekly
Administration
IGF-1 LR3
Subcutaneous injection
PEG-MGF
Subcutaneous injection
Cycle Length
IGF-1 LR3
4-6 weeks
PEG-MGF
4-6 weeks
Onset Speed
IGF-1 LR3
Rapid (hours to days)
PEG-MGF
Moderate (1-2 weeks)
Evidence Level
IGF-1 LR3
Strong preclinical (extensive animal studies)
PEG-MGF
Strong preclinical (extensive animal studies)
Efficacy
Benefit
ratings
Muscle Growth
Recovery Speed
Nutrient Utilization
Muscle Recovery
Stem Cell Activation
Tissue Healing
Technical Data
Compound
specifications
IGF-1 LR3
Molecular Formula
C400H625N111O115S9
Molecular Weight
9111.4 g/mol
Half-Life
20-30 hours
Bioavailability
High when injected subcutaneously or intramuscularly
CAS Number
946870-92-4
PEG-MGF
Molecular Formula
C121H200N42O39 (peptide core)
Molecular Weight
2867.2 g/mol (peptide) + PEG moiety
Half-Life
48-72 hours (vs. minutes for unmodified MGF)
Bioavailability
High when injected subcutaneously or intramuscularly; PEGylation protects from rapid degradation
CAS Number
108174-48-7
Protocols
Dosing
tiers
IGF-1 LR3
PEG-MGF
Applications
Best
suited for
IGF-1 LR3
Serious Muscle Builders
If you're pushing hard in the gym and want to maximize every rep, IGF-1 LR3 helps your muscles grow through both hypertrophy (bigger cells) AND hyperplasia (more cells). That's a one-two punch that few other compounds offer.
Recovery-Focused Athletes
Train hard, recover faster. IGF-1 LR3 accelerates tissue repair and reduces the time you need between intense sessions. It's particularly valuable during high-volume training blocks or when preparing for competition.
Body Recomposition Goals
Looking to build muscle while losing fat? IGF-1 LR3 helps shuttle nutrients into muscle cells while improving how your body uses fat for fuel. Combined with proper diet, it supports that lean, muscular physique.
Post-Injury Rehabilitation
IGF-1 is your body's natural repair signal. The LR3 version stays active longer, potentially helping injured tissues heal more completely. Athletes recovering from muscle strains or tears may find it particularly beneficial.
PEG-MGF
Athletes Recovering from Muscle Injuries
If you've pulled, strained, or torn a muscle, PEG-MGF could be a game-changer. It activates the satellite cells (muscle stem cells) that your body uses to repair damaged fibers, potentially speeding up your return to training.
Serious Lifters and Bodybuilders
Heavy training creates microdamage in your muscles—that's actually how they grow. PEG-MGF amplifies your body's repair response, potentially helping you recover faster between sessions and make more gains from each workout.
Older Adults Concerned About Muscle Loss
As we age, our muscles become less responsive to the 'repair and grow' signals. Research shows older adults don't produce as much MGF after exercise. Supplementing with PEG-MGF might help restore some of that youthful repair capacity.
Post-Surgical Recovery (Under Medical Supervision)
If you're recovering from surgery involving muscle tissue, PEG-MGF's ability to recruit stem cells and promote tissue repair could support faster healing. Always use under medical guidance in these situations.
Safety Profile
Side
effects
IGF-1 LR3
Common
- Hypoglycemia (low blood sugar)
- Injection site reactions
- Water retention
- Headaches
Uncommon
- Joint pain or stiffness
- Numbness or tingling
Serious
- Severe hypoglycemia
PEG-MGF
Common
- Injection site irritation
- Mild headache
- Temporary fatigue
Uncommon
- Localized swelling
- Blood sugar fluctuations
Serious
- Allergic reaction
Research Status
Safety
& evidence
IGF-1 LR3
Evidence Level
Strong preclinical (extensive animal studies)
FDA Status
Research compound
Safety Overview
IGF-1 LR3 has been extensively studied in research settings and shows a predictable side effect profile when used responsibly. The primary concern is hypoglycemia, which is manageable with proper nutrition timing. Long-term safety data in humans is limited since it's used as a research compound. Joint discomfort and water retention are generally mild and resolve when cycling off.
Contraindications
- xActive cancer or history of cancer
- xPregnancy or breastfeeding
- xDiabetic retinopathy or uncontrolled diabetes
- xKnown hypersensitivity to IGF-1 or related peptides
- xChildren and adolescents (can affect growth plates)
PEG-MGF
Evidence Level
Strong preclinical (extensive animal studies)
FDA Status
Research compound
Safety Overview
PEG-MGF (pegylated mechano growth factor) demonstrates good tolerability in preclinical studies with minimal immunogenicity from pegylation modifications. Intramuscular administration shows local tissue responses consistent with growth factor activity. No serious systemic adverse events in animal models at therapeutic doses. Pegylation extends half-life from 2 hours (native IGF-1 Ec) to 24+ hours, reducing injection frequency while maintaining safety profile similar to parent peptide.
Contraindications
- xActive cancer or history of cancer
- xPregnancy or breastfeeding
- xKnown allergy to peptide components or PEG
- xChildren and adolescents
- xUncontrolled diabetes
Decision Guide
Which is
right for you?
Choose IGF-1 LR3 if...
- Muscle growth and hypertrophy
- Post-workout recovery
- Body recomposition
- Athletic performance enhancement
Choose PEG-MGF if...
- Muscle injury recovery
- Post-workout muscle repair
- Combating muscle wasting
- Supporting bone healing