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ToolsCompareP21 vs Orforglipron

P21 vs Orforglipron

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

Cognitive EnhancementAnti-Aging & Longevity
P21
GLP-1 / Weight Loss Agonists
Orforglipron
Summary
P21 is a synthetic peptide derived from CNTF (ciliary neurotrophic factor) that promotes hippocampal neurogenesis, enhances memory and spatial learning, and may reduce amyloid-beta pathology. It is used as a neurogenic and cognitive enhancer with potential anti-Alzheimer's applications.
Orforglipron is an oral, once-daily small-molecule GLP-1 receptor agonist developed by Eli Lilly. Unlike injectable GLP-1 peptides, it is a non-peptide compound absorbed orally without food restrictions, representing a major convenience advancement. Phase 2 trials showed up to 9.4% weight loss at 36 weeks, and Phase 3 trials (ATTAIN program) are ongoing for obesity and type 2 diabetes.
Half-Life
Not well characterized; likely short, but neurogenic effects persist long after administration
~12 hours (once-daily oral dosing)
Admin Route
SubQ, Intranasal
Oral
Research
Typical Dose
100–500 mcg
12 mg → 24 mg → 36 mg → 45 mg
Frequency
Once daily
Once daily
Key Benefits
  • Promotes hippocampal neurogenesis
  • Enhances spatial memory and learning
  • Increases BDNF expression
  • Reduces amyloid-beta plaque formation (animal models)
  • Anti-tau pathology potential
  • Cognitive enhancement without stimulant effects
  • Potential therapeutic for Alzheimer's and cognitive aging
  • Oral pill — no injections required
  • Once-daily dosing without food restrictions (unlike oral semaglutide)
  • Up to 9.4% body weight reduction in Phase 2 at 36 weeks
  • Significant HbA1c reduction in type 2 diabetes trials
  • Small-molecule stability — no cold chain requirements
  • Broadens access for injection-averse patients
  • Potential class-defining convenience advantage over injectable GLP-1s
Side Effects
  • Generally well tolerated in animal studies
  • Limited human clinical data
  • Injection site reactions
  • Potential mild fatigue at initiation
  • Nausea (most common, dose-dependent)
  • Vomiting
  • Diarrhea
  • Decreased appetite
  • +2 more
Stacks With