Thymosin Alpha-1 vs P21

A detailed comparison to help you understand the differences and choose the right peptide for your research goals.

Thymosin Alpha-1

Thymosin Alpha-1 is a peptide naturally produced by the thymus gland that plays a crucial role in immune system modulation. It is approved in over 35 countries for various conditions including hepatitis B and C.

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P21

P21 is a synthetic peptide derived from Cerebrolysin, specifically designed to mimic the neurotrophic effects of the parent compound. It promotes neurogenesis and has shown cognitive-enhancing properties in research.

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Side-by-Side Comparison

AspectThymosin Alpha-1P21
MechanismEnhances T-cell function and maturation, stimulates dendritic cell activity, and modulates cytokine production. Promotes the differentiation of stem cells into mature T lymphocytes.Inhibits glycogen synthase kinase-3β (GSK-3β) and activates CREB signaling pathway. This promotes BDNF expression, neurogenesis in the hippocampus, and synaptic plasticity.
Typical DosageClinical dosing typically ranges from 1.6mg to 6.4mg administered subcutaneously 2-3 times weekly. Research protocols may vary.Research protocols typically use 1-5mg administered intranasally or subcutaneously. Often used in cycles of 2-4 weeks.
AdministrationSubcutaneous injection. Often used in cycles or as part of comprehensive immune support protocols.Can be administered intranasally for direct CNS access or subcutaneously. Best used cyclically rather than continuously.
Side EffectsGenerally well-tolerated. Rare side effects include injection site reactions, mild flu-like symptoms, and temporary fatigue.Limited data. Reported effects include mild headache, temporary brain fog during initial use, and fatigue.
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Key Differences

Unique to Thymosin Alpha-1:

Unique to P21:

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