Thymosin Beta-4 vs P21
Side-by-side comparison of key properties, dosing, and research.
Recovery & RepairAnti-Aging & Longevity
Thymosin Beta-4Cognitive EnhancementAnti-Aging & Longevity
P21- Summary
- Thymosin Beta-4 is an endogenous 43-amino acid peptide that is the primary intracellular actin sequestering peptide. It promotes tissue repair, reduces inflammation, regenerates hair follicles, and protects cardiac tissue. Closely related to TB-500 (the active fragment), it is used for systemic tissue recovery and anti-aging.
- 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
- Not well characterized; likely similar to TB-500 (~1–2 hours)
- Not well characterized; likely short, but neurogenic effects persist long after administration
- Admin Route
- SubQ, IM
- SubQ, Intranasal
- Research
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- Typical Dose
- 5–10 mg
- 100–500 mcg
- Frequency
- 2x per week (loading), then 1x per week (maintenance)
- Once daily
- Key Benefits
- Systemic tissue repair and regeneration
- Promotes cardiac recovery after myocardial infarction
- Hair follicle regeneration and anti-hair-loss
- Anti-inflammatory (systemic)
- Wound healing acceleration
- Neuroprotection after brain injury
- Protects against ischemia-reperfusion injury
- Anti-aging at cellular level
- Synergizes powerfully with BPC-157
- 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
- Generally very well tolerated
- Injection site reactions
- Mild fatigue at initiation (repair signaling)
- Rare: mild inflammatory response
- +1 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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