$ 105 / 5mg
999 in stock (can be backordered)
P21 (also known as p21/WAF1/CIP1-derived peptide) is a research peptide based on the cyclin-dependent kinase inhibitor p21, a key regulator of cell-cycle arrest at the G1/S checkpoint. In peptide research, P21 has been studied for its dual role: modulating cell-cycle progression in senescence models and promoting neurogenesis in hippocampal research — making it a unique tool bridging aging biology and neuroscience.
The P21 peptide fragment interacts with proliferating cell nuclear antigen (PCNA), disrupting the p21-PCNA complex that normally inhibits DNA replication. In neural progenitor cell models, this disruption has been associated with increased cell proliferation and neurogenesis. Conversely, in senescence research, p21 pathway activation triggers stable cell-cycle arrest — making the peptide valuable for studying both pro-proliferative and anti-proliferative signaling depending on experimental context.
Researchers studying cellular aging pair P21 with FOXO4-DRI for senolytic clearance and Epithalon for telomerase-activation approaches. For neurogenesis-focused research, Semax and Selank offer complementary nootropic and neuroprotective pathways.
Each 5 mg vial contains P21 peptide manufactured in the USA under ISO-certified conditions. Verified to ≥99% purity by HPLC analysis, with endotoxin screening below 0.1 EU/mg. Certificate of Analysis (COA) available upon request. For laboratory research use only.
Lyophilized P21 peptide should be stored at -20°C in a sealed, desiccated container protected from light and moisture for optimal long-term stability. Reconstitute with bacteriostatic water and store the resulting solution at 2–8°C, using all reconstituted material within 28 days. Prepare single-use aliquots at the time of reconstitution to prevent degradation from repeated freeze-thaw cycles. All handling should follow standard aseptic laboratory procedures for peptide research. This product is for laboratory research use only and is not intended for human consumption.
The p21/WAF1/CIP1 protein was first identified in 1993 by Dr. Bert Vogelstein’s laboratory at Johns Hopkins University as a critical downstream effector of the p53 tumor suppressor pathway. The p21-derived peptide fragments used in neurogenesis research were subsequently characterized by teams studying PCNA-binding domains and their effects on neural progenitor cell proliferation. Research on P21 peptide and the broader p21-PCNA signaling axis has been published in over 200 peer-reviewed articles in journals including Cell, Nature, Science, and The Journal of Neuroscience. Academic groups at institutions such as Johns Hopkins, the Salk Institute, and the Karolinska Institutet have contributed to understanding how p21-PCNA disruption promotes adult hippocampal neurogenesis. P21 peptide continues to serve as a key research tool at the intersection of cell-cycle biology, senescence research, and regenerative neuroscience.
P21 peptide modulates the p21-PCNA interaction, which plays opposite roles depending on the cellular context — promoting neurogenesis by releasing proliferative capacity in neural progenitor cells, while in other models the p21 pathway enforces senescence-associated cell-cycle arrest. This dual functionality makes P21 a versatile research tool for both aging biology and neuroscience. The product is supplied for laboratory research use only.
Each 5 mg vial is manufactured in the USA under ISO-certified conditions and verified to ≥99% purity by HPLC analysis, with endotoxin screening confirmed below 0.1 EU/mg. A Certificate of Analysis (COA) with complete analytical data is available upon request for research compliance records.
PCNA (proliferating cell nuclear antigen) is a DNA-replication clamp that is normally inhibited by endogenous p21 to halt cell division. P21 peptide disrupts this p21-PCNA complex, allowing researchers to study the downstream effects of releasing this cell-cycle brake in various cellular models. This compound is designated for research use only and is not intended for therapeutic applications.
