Px
PeptideCalc
💪

Muscle Growth Peptides

Muscle growth peptides work through IGF-1 signaling, satellite cell activation, and growth hormone axis stimulation. IGF-1 LR3 directly activates anabolic pathways in muscle tissue. Follistatin-344 in...

Overview

Muscle growth peptides work through IGF-1 signaling, satellite cell activation, and growth hormone axis stimulation. IGF-1 LR3 directly activates anabolic pathways in muscle tissue. Follistatin-344 inhibits myostatin — the protein that limits muscle growth. GH secretagogues enhance the endogenous anabolic hormone environment. These are among the most researched compounds for body recomposition.

Calculate Your Dose

Use our calculator for these peptides — presets auto-fill the math.

Open Calculator →

IGF-1 LR3

Insulin-like Growth Factor 1 Long R3

Mechanism

Long-acting analogue of IGF-1. Directly activates IGF-1 receptors in muscle tissue, promoting satellite cell differentiation (muscle stem cells) and protein synthesis. 3x longer half-life than regular IGF-1.

Benefits

  • ✓Satellite cell activation (permanent muscle fiber increase)
  • ✓Enhanced nutrient partitioning
  • ✓Direct anabolic effect independent of GH
  • ✓Recovery enhancement
  • ✓Anti-catabolic

Dosing

10–20mcg per day SubQ or IM near trained muscle. Start at 10mcg.

Reconstitution

1mg + 3mL BAC = 333mcg/mL. Draw 3 units for 10mcg, 6 units for 20mcg.

Cycle Length

4–6 weeks on, 4–6 weeks off. IGF-1 receptor downregulation occurs with prolonged use.

Timing

Post-workout on training days, or morning on non-training days.

Stacks Well With

Ipamorelin/CJC-1295, BPC-157 (injury protection during aggressive training)

Cautions

Hypoglycemia possible — have food available after injection. Avoid with cancer history (powerful mitogen). Start very low (10mcg).

Calculate IGF-1 LR3 dose →

Follistatin-344

FST-344

Mechanism

Glycoprotein that inhibits myostatin and activin — proteins that limit muscle growth. Essentially removes the brake on muscle development.

Benefits

  • ✓Myostatin inhibition
  • ✓Enhanced muscle fiber growth potential
  • ✓Improved recovery
  • ✓Complementary to anabolic peptides

Dosing

100mcg/day × 10 days. Often cycled in short bursts.

Reconstitution

Varies by supplier. Typically 1mg vial. Consult supplier for BAC water amount.

Cycle Length

10-day cycles, 2–3 times per year.

Timing

Daily SubQ during cycle.

Stacks Well With

IGF-1 LR3, GH secretagogues

Cautions

Limited human research. Cancer concern (cell proliferation). Avoid with cancer history.

Calculate Follistatin-344 dose →

Frequently Asked Questions