Orforglipron vs P21
Side-by-side comparison of key properties, dosing, and research.
GLP-1 / Weight Loss Agonists
OrforglipronCognitive EnhancementAnti-Aging & Longevity
P21- Summary
- 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.
- 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.
- Half-Life
- ~12 hours (once-daily oral dosing)
- Not well characterized; likely short, but neurogenic effects persist long after administration
- Admin Route
- Oral
- SubQ, Intranasal
- Research
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- Typical Dose
- 12 mg → 24 mg → 36 mg → 45 mg
- 100–500 mcg
- Frequency
- Once daily
- Once daily
- Key Benefits
- 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
- 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
- Side Effects
- Nausea (most common, dose-dependent)
- Vomiting
- Diarrhea
- Decreased appetite
- +2 more
- Generally well tolerated in animal studies
- Limited human clinical data
- Injection site reactions
- Potential mild fatigue at initiation
- Stacks With
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