P21 vs PT-141 (Bremelanotide)
Side-by-side comparison of key properties, dosing, and research.
Cognitive EnhancementAnti-Aging & Longevity
P21Sexual Health & Libido
PT-141 (Bremelanotide)- 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.
- PT-141 (Bremelanotide) is a cyclic peptide melanocortin receptor agonist that enhances sexual desire and arousal through central nervous system mechanisms. It is FDA-approved as Vyleesi for premenopausal women with hypoactive sexual desire disorder (HSDD).
- Half-Life
- Not well characterized; likely short, but neurogenic effects persist long after administration
- 2–3 hours
- Admin Route
- SubQ, Intranasal
- SubQ
- Research
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- Typical Dose
- 100–500 mcg
- 0.5–1.75 mg
- Frequency
- Once daily
- As needed (not 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
- Enhances sexual desire and libido in both men and women
- Improves arousal through central nervous system activation
- Effective for psychological erectile dysfunction
- Works for female sexual arousal disorder
- May improve sexual satisfaction and intensity
- Fast-acting — effects within 45–60 minutes
- FDA-approved for HSDD in premenopausal women
- Side Effects
- Generally well tolerated in animal studies
- Limited human clinical data
- Injection site reactions
- Potential mild fatigue at initiation
- Nausea (most common — 40% of users in clinical trials)
- Facial flushing and warmth
- Transient blood pressure changes (typically increase then normalize)
- Headache
- +2 more
- Stacks With
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