P21 (P021)

1. Basic Overview

• Amino Acid Sequence: Ac-DGGLAG-NH₂
• Molecular Weight: 529.55 Da
• CAS: No official universal CAS registry number (novel research peptide)
• Form: Lyophilized white crystalline powder
• Core Feature: Can cross the blood-brain barrier (BBB) in preclinical animal models. It replicates CNTF’s neuroprotective benefits without severe weight loss/cachexia side effects caused by full-length CNTF protein.

2. Mechanism of Action

1. Upregulate BDNF Production

   Stimulates elevated Brain-Derived Neurotrophic Factor (BDNF) expression within the hippocampus. BDNF supports neuronal survival, dendritic spine growth and synaptic plasticity.

2. Inhibit GSK-3β Kinase

   Suppresses activity of glycogen synthase kinase 3-beta. This reduces abnormal hyperphosphorylation of tau protein, one major hallmark neurofibrillary tangle pathology in Alzheimer’s disease.

3. Reduce Amyloid Beta Toxicity

   Modulates APP processing, lowering the generation and aggregation of Aβ peptide in preclinical AD models.

4. Promote Hippocampal Neurogenesis

   Supports the generation of new neurons in the dentate gyrus, a brain region critical for memory formation and learning.

5. Modulate CNTF/LIF Pathway

   Selectively activates neurotrophic signaling while avoiding the LIF-mediated metabolic wasting effects associated with native CNTF.

3. Main Research Applications

• Alzheimer’s disease & tauopathy preclinical animal models
• Hippocampal neurogenesis, memory and cognitive function research
• Synaptic plasticity and neuronal regeneration experiments
• Neuroinflammation and neurodegeneration pathway studies
• Traumatic brain injury (TBI) neuronal recovery models
• Comparative research: P21 vs full-length CNTF; P21 combined with nootropic peptides
• Age-related cognitive decline and brain senescence laboratory studies

4. Reconstitution Instructions (Lyophilized Vial)

1. Let peptide vial reach room temperature; disinfect rubber stopper with alcohol wipe.
2. Slowly inject Bacteriostatic Water along the inner glass wall. Avoid direct impact onto lyophilized powder.

Recommended mixing scheme: 10mg powder + 2mL BAC water → Concentration = 5 mg/mL

3. Gently rotate the vial to dissolve powder. DO NOT shake violently to prevent peptide structural degradation. Qualified solution is clear and colourless.
4. Storage Requirements

• Unreconstituted lyophilized powder: Hermetically sealed, stored at -20°C, protected from light. Stable for up to 24 months.
• Reconstituted peptide solution: Refrigerate 2°C ~ 8°C, stable within 28 days. Do not freeze reconstituted liquid; repeated freeze-thaw impairs activity.

5. Research Administration Protocols

1) Subcutaneous Injection (Widely used)

• Low starting tolerance dose: 100–250 mcg once daily
• Standard experimental dose: 300–500 mcg once daily
• High experimental dose: Up to 750 mcg once daily (limited long-term safety data)
• Injection site: Lower abdomen or anterior thigh; rotate injection positions regularly.

2) Intranasal Administration (Preferred for CNS-targeted research)

• Working concentration: 1–2 mg/mL reconstituted solution
• Dosage reference: 50–200 mcg once daily via nasal instillation

Reference Experimental Cycle

6. Precautions & Observed Adverse Reactions

1. Pure laboratory research compound. Not authorized for human therapeutic use.
2. Strict aseptic technique required during reconstitution to prevent microbial contamination.
3. Discard solution immediately if turbidity, precipitation or discoloration appears.
4. Within standard experimental doses, systemic adverse reactions are rare. Occasional mild transient redness may appear at subcutaneous injection sites.
5. Avoid concurrent use with other CNTF / neurotrophic mimetics unless specified by your research protocol.
6. No large-scale human clinical trial data exists. All results are limited to cell culture and rodent preclinical models.

Short Version 

P21 (P021)

Reconstitution

Reference Research Dosage