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

Get it free
ToolsCompareTirzepatide vs Pentapeptide-18

Tirzepatide vs Pentapeptide-18

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

GLP-1 / Weight Loss Agonists
Tirzepatide
Skin & CosmeticAnti-Aging & Longevity
Pentapeptide-18
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).
Pentapeptide-18 (Leuphasyl) is a synthetic pentapeptide that mimics the sequence of enkephalin, an endogenous neuropeptide. It acts on neuronal pain receptors in facial muscles to reduce muscle contraction intensity and depth of expression lines, functioning similarly to Argireline (Acetyl Hexapeptide-3) but via a different receptor mechanism.
Half-Life
~5 days
Not applicable (topical)
Admin Route
SubQ
Topical
Research
Typical Dose
2.5 mg → 5 mg → 7.5 mg → 10 mg → 12.5 mg → 15 mg
0.005–0.05% in formulation
Frequency
Once weekly, subcutaneous
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
  • Reduces depth of expression lines (forehead, crow's feet, glabellar)
  • Inhibits acetylcholine release for muscle-relaxing effect
  • Complementary mechanism to Argireline for enhanced anti-wrinkle activity
  • Reversible and well-tolerated
  • No risk of systemic paralysis at cosmetic concentrations
  • Suitable for daily use in serums and creams
Side Effects
  • Nausea (most common during titration)
  • Vomiting
  • Diarrhea or constipation
  • Abdominal pain
  • +3 more
  • Generally very well-tolerated topically
  • Rare skin sensitivity or mild irritation
  • Theoretical opioid receptor desensitization with very prolonged high-dose use (not documented cosmetically)
Stacks With