Source comparison
IGF-1 LR3 for Muscle Growth: Dosing Protocol Comparison
Different research models use varying dosing strategies depending on outcome endpoints, study duration, and species. The table below compares the three most commonly cited dosing protocols in published literature. Low-Dose Chronic (rodent models) 20–40 mcg/kg/
This comparison does not assign a generated winner or score.
- Different research models use varying dosing strategies depending on outcome endpoints, study duration, and species. The table below compares the three most commonly cited dosing protocols in published literature.
- Low-Dose Chronic (rodent models)
- 20–40 mcg/kg/day
- Once daily subcutaneous
- 28–56 days
- Lean mass gain, fiber CSA increase
- Sustained anabolic effect with minimal hypoglycemia risk; requires 3–4 weeks for measurable hypertrophy
- Moderate-Dose Acute (injury models)
- 50–100 mcg/kg/day
- 7–14 days
- Satellite cell activation, regeneration rate
- Rapid proliferative response; limited hypertrophy due to short duration; higher hypoglycemia incidence
- High-Dose Pulsed (experimental)
- 100–200 mcg/kg every 48–72 hours
- Intermittent subcutaneous
- 21–28 days
- mTOR pathway activation, receptor sensitivity
- High receptor occupancy without daily accumulation; mixed results on net hypertrophy; severe hypoglycemia risk above 150 mcg/kg
- The most consistent muscle growth outcomes in peer-reviewed studies have come from the low-dose chronic protocol. A 2005 study published in the American Journal of Physiology. Endocrinology and Metabolism administered IGF-1 LR3 at 30 mcg/kg/day for 28 days to aged rats and observed 12% increase in gastrocnemius mass, 18% increase in type IIb fiber cross-sectional area, and significant upregulation of p70S6K phosphorylation. Hypoglycemia (plasma glucose below 60 mg/dL) occurred in fewer than 10% of treated animals. High-dose protocols above 100 mcg/kg consistently produce hypoglycemia in 40–60% of subjects, limiting practical application despite theoretical anabolic advantage.