New — Free Peptide Starter Guide (2026): 13 chapters, 34 cited studies

Get it free
ToolsCompareTirzepatide vs IGF-1 LR3

Tirzepatide vs IGF-1 LR3

Side-by-side comparison of key properties, dosing, and research.

GLP-1 / Weight Loss Agonists
Tirzepatide
Anabolic & IGF
IGF-1 LR3
Summary
Tirzepatide is an FDA-approved dual GIP/GLP-1 receptor agonist that produces greater weight loss than semaglutide in head-to-head trials. SURMOUNT-1 trial showed average 21% body weight reduction at 72 weeks at the highest dose. Marketed as Mounjaro (diabetes) and Zepbound (obesity).
IGF-1 LR3 is a synthetic analog of Insulin-like Growth Factor-1 with an extended half-life. It is one of the most potent anabolic peptides available, directly stimulating muscle cell hyperplasia and hypertrophy, and is the downstream mediator of many of GH's anabolic effects.
Half-Life
~5 days
20–30 hours
Admin Route
SubQ
SubQ, IM
Research
Typical Dose
2.5 mg → 5 mg → 7.5 mg → 10 mg → 12.5 mg → 15 mg
40–80 mcg
Frequency
Once weekly, subcutaneous
Once daily or split twice daily
Key Benefits
  • Average 21% body weight reduction at highest dose (SURMOUNT-1)
  • Superior to semaglutide in head-to-head SURPASS trials
  • Dual GIP/GLP-1 mechanism for enhanced metabolic control
  • Significant reduction in HbA1c for type 2 diabetes
  • Improved cardiovascular risk markers
  • Reduces visceral fat preferentially
  • FDA-approved for T2DM (Mounjaro) and obesity (Zepbound)
  • Weekly dosing
  • Direct muscle hypertrophy via IGF-1R stimulation
  • Muscle hyperplasia (new fiber formation) — unique among peptides
  • Rapid gains in lean muscle mass
  • Accelerated recovery from training and injury
  • Increased nutrient uptake by muscle cells
  • Fat oxidation enhancement
  • Bone density improvement
  • Cartilage and connective tissue repair
Side Effects
  • Nausea (most common during titration)
  • Vomiting
  • Diarrhea or constipation
  • Abdominal pain
  • +3 more
  • Hypoglycemia (significant risk — insulin-like activity)
  • Acromegaly-like effects with excessive long-term use
  • Jaw and hand swelling
  • Organ hypertrophy with extreme doses
  • +2 more
Stacks With