Neurotrophic signaling research
1A 2026 3xTg-AD mouse study detected brain microstructure differences on diffusion MRI after early P021 treatment. It did not test benefit or safety in people.
Mind & sleep
P21
P021 neurotrophic peptidomimetic
Lab studiesNerve-cell growth signals1
No FDA-approved product identified for this exact research entry in the targeted review.
What does it do?
CNTF-derived investigational nootropic with cognitive and neuroprotective findings in animals, not established human benefits.
Approved & studied uses
Evidence limits
View research →No controlled human P021 efficacy or pharmacokinetic study was verified.1
1 distinct primary sources or abstracts checked. Evidence may concern a parent compound, individual blend ingredient, animal, or cell model; it does not necessarily establish a benefit for this exact product.
Evidence definitions →Key safety information
All risks →Evidence limitation
Mouse MRI outcomes cannot establish a safe human dose.1
No FDA-approved product identified for this exact research entry in the targeted review.
Amino-acid sequence
An exact sequence has not been verified for this formulation.
Reference identity · not independently confirmed16
Length5 amino acids (with modifications)
Molecular weight · Da578.3 Da
Formula, sequence notation & identity
Modified tetrapeptide derivative
The exact formulation, clinical benefits and long-term safety require further verification.
Pep-Pedia identity details
5 amino acids (with modifications) · 578.3 Da
Ac-DGGLAG-NH2The reference lists 5 residues, but its sequence contains 6. No exact sequence is inferred from these conflicting values.
Reference description; checked chemical identity above takes precedence when available.16
Pharmacokinetics
How long does it stay in the body?
Unverified reference estimateNot independently confirmed
Reference half-life6 hours15
Route / formulationSource page: Nasal. Exact PK route not verified.
This value is reported by a secondary reference. The stated attribution has not been independently verified as a route- and formulation-matched human PK measurement.
50%of reference level
Illustrative scenario using an unverified reference estimate.
About 3% remaining after 30 h
Five half-lives in this estimated model. This is not a prediction of when effects stop.
Evidence and model details
Population: Not established by the reference estimate
Source’s stated attribution: Li et al. FEBS Lett 2010
Source’s reported peak time: 15 min. This has not been independently confirmed and is not used in the elimination curve.
100 × 2−time / half-life. Time zero is a reference level, not the moment of administration. Absorption, repeated dosing, metabolites and clinical effects are not modeled. Five half-lives leaves 3.125%, not zero. This curve cannot determine a dosing interval.
What to expect
Study outcomes
New mouse imaging study
No controlled human P021 efficacy or pharmacokinetic study was verified.1
Community poll 10 topics · Pep-Pedia snapshot
Voluntary, unverified reports. These percentages do not measure effectiveness or safety.
Experience
Number of responses to this question: not disclosed.
Duration of use
Number of responses to this question: not disclosed.
Age range
The source hides 1 additional categories. Their labels and percentages are unavailable.
Number of responses to this question: not disclosed.
Gender
Number of responses to this question: not disclosed.
Primary goal
Number of responses to this question: not disclosed.
Effectiveness
The source hides 1 additional categories. Their labels and percentages are unavailable.
Number of responses to this question: not disclosed.
Side effects
Number of responses to this question: not disclosed.
Dosage frequency
Number of responses to this question: not disclosed.
Would recommend
Number of responses to this question: not disclosed.
How discovered
Number of responses to this question: not disclosed.
Source & limitations
The source displays “120 responses” for this profile. This is not a confirmed participant count or a denominator for individual questions.
- Voluntary self-reports from Pep-Pedia visitors; identity, treatment, outcomes and timing are unverified. These data are not efficacy or safety estimates.
- The source displays a profile-wide response label, not a confirmed unique participant count. It stays unchanged across questions. Question-specific denominators and absolute option counts are not exposed.
- Only the top five categories are displayed for some questions. Extra categories are retained as an undisplayed-category count; their labels and percentages are unavailable.
- Displayed percentages are rounded. They may not total 100%, especially where categories are hidden.
- This is a dated snapshot, not a live survey or current recommendation.
Protocols
Doses & schedules
Compare purpose, amount, route, frequency, and duration.
Source corrections
Interaction compatibility is a reference claim, not demonstrated combination safety.
Route
Scroll to compare all columns →
| Route | Dose | Frequency | Goal / evidence | Duration | References |
|---|---|---|---|---|---|
| IntranasalNasal | 500 mcg-1 mg | 1x daily | Cognitive enhancementReference report | 4-6 weeks | 16 |
Population Population not independently verified; see the reference and linked research. Context Reported in Pep-Pedia’s educational protocol table. Study attribution and applicability to this exact product are not independently established. Interaction compatibility is a reference claim, not demonstrated combination safety. Source tabs Nasal | |||||
| IntranasalNasal | 1-2 mg | As needed | Acute cognitive boostReference report | 4-6 weeks | 16 |
Population Population not independently verified; see the reference and linked research. Context Reported in Pep-Pedia’s educational protocol table. Study attribution and applicability to this exact product are not independently established. Interaction compatibility is a reference claim, not demonstrated combination safety. Source tabs Nasal | |||||
| IntranasalNasal | 500 mcg | 1x daily | Maintenance/neuroprotectionReference report | 4-6 weeks | 16 |
Population Population not independently verified; see the reference and linked research. Context Reported in Pep-Pedia’s educational protocol table. Study attribution and applicability to this exact product are not independently established. Interaction compatibility is a reference claim, not demonstrated combination safety. Source tabs Nasal | |||||
| IntranasalNasal | 500 mcg | 1x daily | Initial assessmentReference report | 4-6 weeks | 16 |
Population Population not independently verified; see the reference and linked research. Context Reported in Pep-Pedia’s educational protocol table. Study attribution and applicability to this exact product are not independently established. Interaction compatibility is a reference claim, not demonstrated combination safety. Source tabs Nasal | |||||
| SubQ | 100-300 mcg | 1x daily | Cognitive enhancementReference report | 4-6 weeks | 16 |
Population Population not independently verified; see the reference and linked research. Context Reported in Pep-Pedia’s educational protocol table. Study attribution and applicability to this exact product are not independently established. Interaction compatibility is a reference claim, not demonstrated combination safety. Source tabs Injectable | |||||
| SubQ | 300-500 mcg | 1x daily | NeuroprotectionReference report | 4-6 weeks | 16 |
Population Population not independently verified; see the reference and linked research. Context Reported in Pep-Pedia’s educational protocol table. Study attribution and applicability to this exact product are not independently established. Interaction compatibility is a reference claim, not demonstrated combination safety. Source tabs Injectable | |||||
| SubQ | 200-300 mcg | 1x daily | Memory supportReference report | 4-6 weeks | 16 |
Population Population not independently verified; see the reference and linked research. Context Reported in Pep-Pedia’s educational protocol table. Study attribution and applicability to this exact product are not independently established. Interaction compatibility is a reference claim, not demonstrated combination safety. Source tabs Injectable | |||||
| SubQ | 100 mcg | 1x daily | Initial trial/assessmentReference report | 4-6 weeks | 16 |
Population Population not independently verified; see the reference and linked research. Context Reported in Pep-Pedia’s educational protocol table. Study attribution and applicability to this exact product are not independently established. Interaction compatibility is a reference claim, not demonstrated combination safety. Source tabs Injectable | |||||
No protocols match these filters.
Study and label doses retain their study context. Reference reports are unvalidated practices, not personal treatment instructions. Ranges remain ranges; escalation stages are labeled.
Reported use periods and breaks. These do not establish a safe cycle or prove that breaks prevent tolerance.
Nasal
- Use period
- 4-6 weeks
- Break
- 2-4 weeks between cycles
Reported timing
Morning or as needed for acute effects
Injectable
- Use period
- 4-6 weeks
- Break
- 2-4 weeks between cycles
Reported timing
Morning or consistent daily timing
Side effects & safety
Evidence limitation
Mouse MRI outcomes cannot establish a safe human dose.
1Evidence limitation
Long-term neurologic and systemic safety of marketed P21 products remain unverified.
1Evidence
No verified human trials; long-term safety unknown.
Stop symptoms
Severe headache, neurological or mood changes, vomiting, infection, persistent injection/nasal irritation or nosebleeds.
Pregnancy
Safety unestablished in pregnancy/breastfeeding.
Not a complete safety screen. Discuss health decisions with a qualified clinician.
Combinations & interactions
9 entriesCheck cautions and reported pairings. A compatibility claim does not establish that a combination is safe.
Dihexa
Caution reportedOverlapping growth signaling.16
Reference report · Pep-Pedia label: Use CautionAdamax
Unverified pairingUnproven cognitive pairing.16
Reference report · Pep-Pedia label: SynergisticSemax
Unverified pairingUnstudied pairing.16
Reference report · Pep-Pedia label: CompatibleSelank
Unverified pairingUnstudied pairing.16
Reference report · Pep-Pedia label: CompatibleBPC-157
Unverified pairingUnstudied pairing.16
Reference report · Pep-Pedia label: CompatibleCerebrolysin
Related compoundRelated neurotrophic goals; not equivalent.16
Reference report · Pep-Pedia label: SimilarNAD+
Unverified pairingUnstudied pairing.16
Reference report · Pep-Pedia label: CompatibleEpitalon
Unverified pairingUnstudied pairing.16
Reference report · Pep-Pedia label: CompatibleOther medicines or peptides
Not establishedNo exact-product human interaction study was verified; lack of evidence is not evidence of safety.2
Research contextNo matching interactions. Try another name or filter.
Reconstitution
No product-specific preparation or stability instruction was verified. A dilution calculation does not establish suitability for injection.2
Reference preparation details
Reported handling information, not a validated formulation or instruction to prepare an injectable product.
Nasal
The source reports nasal preparation and a stated 0.1 mL spray volume.
- Solvents mentioned
- Bacteriostatic water / Sterile saline
- Reported parameters
- Amount per spray depends on actual calibrated pump output. · Reported storage: 2–8°C for 14–21 days.
Injectable
Pep-Pedia describes preparation for this route; product-specific stability has not been independently verified.
- Solvents mentioned
- Bacteriostatic water
- Reported parameters
- Source temperature: 2-8°C. · Reported post-preparation interval: 14-30 days.
The source describes gentle mixing and avoiding vigorous shaking.
Appearance & documentation
Appearance and a purity certificate cannot establish sterility, identity, or suitability for injection.
Reported appearanceClear Nasal SolutionReported appearanceProper Spray MechanismReported appearanceCertificate of AnalysisReported variationDilution AccuracyReported concernCloudy or Discolored SolutionReported concernInconsistent Spray
16Available forms
No verified packaging examples included.
Packaging examples, not a market survey. Approved and research products are not interchangeable.
Storage after mixing
Reconstituted research vials
Pep-Pedia reports these handling limits after mixing. They are not validated stability or sterility limits for your vial.
Full storage notes from Pep-Pedia
16Fridge 2-8°C, use within 14-21 days
Fridge 2-8°C, use within 14-30 days
Storage depends on the formulation, diluent, container, and handling. Follow the specific product label or pharmacist’s instructions.
Research findings
PreclinicalSource context
Interaction compatibility is a reference claim, not demonstrated combination safety.
Compound identity & other names
This entry refers to experimental P021, often marketed as P21, rather than the p21 cell-cycle protein. Published work focuses on mouse disease models and cultured cells.
Other names: P021 · Peptide 021 · CNTF mimetic
No FDA-approved product identified for this exact research entry in the targeted review.
How it may work
Proposed LIF/STAT3 inhibition and BDNF-related neuroplasticity; adamantyl modification alters delivery.16
New mouse imaging study
A 2026 3xTg-AD mouse study detected brain microstructure differences on diffusion MRI after early P021 treatment. It did not test benefit or safety in people.
1Research areas and evidence gaps
Neurotrophic signaling research. A 2026 3xTg-AD mouse study detected brain microstructure differences on diffusion MRI after early P021 treatment. It did not test benefit or safety in people.1
- No controlled human P021 efficacy or pharmacokinetic study was verified.
- A product-specific research-vial quantity was not independently verified in this review.
Community reports Unvalidated
Pep-Pedia discusses neurodegeneration research.2
Editorial summary, not a measured community survey, clinical protocol or recommendation.
Search coverage and review status
Added the 2026 transgenic-mouse diffusion-MRI paper; no human efficacy study was verified.
- Checked
- 2026-10-12
- Search
- "P021" 2025 2026 study; "Diffusion MRI measures" "P021"
- Catalog
- Pep-Pedia ↗ · 12 listed references retained
- Targeted search and selected primary-source checks, not an exhaustive systematic review.
- Preserved bibliography entries marked unreviewed have not had their findings independently verified.
AI-prepared summaries. Independent medical editorial review is pending.
References
Original sources and review status. Open a reference to read its summary.
1Diffusion MRI measures detect brain microstructure changes due to early treatment with neurotrophic peptide mimetic P021 in the 3xTg-AD mouse model of Alzheimer’s diseasePrimary source checked
AI-PREPARED SUMMARY
The study detected treatment-associated diffusion-MRI differences after early P021 exposure in mice. Imaging differences in a transgenic model do not establish human dementia efficacy.
New mouse imaging study
A 2026 3xTg-AD mouse study detected brain microstructure differences on diffusion MRI after early P021 treatment. It did not test benefit or safety in people.
Additional research · Checked 2026-10-12
2Pep-Pedia: P21Community source checked
AI-PREPARED SUMMARY
Secondary editorial profile and reported practices; not clinical validation.
3Original P21 Discovery Study - Neurogenesis and Memory Enhancement (2010)Pep-Pedia report · Primary source not checked
AI-PREPARED SUMMARY
Pep-Pedia reports: A related CNTF-derived peptide improved mouse learning and neurogenesis markers; exact P21/P021 sequence identity must be checked.
Reported population / model
Mice
Reported study details
C57Bl6 · IP administration · 4 weeks · Enhanced learning, memory, and neurogenesis
Reported by Pep-Pedia; the linked publication, design, doses and result have not been independently verified here.
Read the Pep-Pedia report ↗Pep-Pedia reference card; original summary of its reported findings · Checked 2026-10-12
43xTg-AD Alzheimer’s Model - Long-term Efficacy (2014)Pep-Pedia report · Primary source not checked
AI-PREPARED SUMMARY
Pep-Pedia reports: Oral P021 improved tau, BDNF and cognition measures in an Alzheimer mouse model; this does not establish equivalence with marketed P21.
Reported population / model
Mice
Reported study details
3xTg-AD · 60 nmol/g feed oral · 6-12 months · Tau reduction, BDNF increase, cognitive rescue
Reported by Pep-Pedia; the linked publication, design, doses and result have not been independently verified here.
Read the Pep-Pedia report ↗Pep-Pedia reference card; original summary of its reported findings · Checked 2026-10-12
5Traumatic Brain Injury Enhancement StudyPep-Pedia report · Primary source not checked
AI-PREPARED SUMMARY
Pep-Pedia reports: Parent Peptide 6 increased new-neuron counts and improved memory after mouse brain injury; the tested parent differs from P21/P021 products.
Reported population / model
Mice
Reported study details
C57Bl6 · CCI model · 50 nmol/animal/day · 30 days · Neurogenesis and memory recovery
Reported by Pep-Pedia; the linked publication, design, doses and result have not been independently verified here.
Read the Pep-Pedia report ↗Pep-Pedia reference card; original summary of its reported findings · Checked 2026-10-12
618-Month Chronic Safety and Efficacy StudyPep-Pedia report · Primary source not checked
AI-PREPARED SUMMARY
Pep-Pedia reports: Long-term P021 exposure reduced pathology and memory deficits in transgenic mice; absence of observed animal harms is not long-term human safety evidence.
Reported population / model
Mice
Reported study details
3xTg-AD and wild-type · Oral · 18 months · Prevention of neurodegeneration
Reported by Pep-Pedia; the linked publication, design, doses and result have not been independently verified here.
Read the Pep-Pedia report ↗Pep-Pedia reference card; original summary of its reported findings · Checked 2026-10-12
7CDKL5 Deficiency Disorder Study (2024)Pep-Pedia report · Primary source not checked
AI-PREPARED SUMMARY
Pep-Pedia reports: CDKL5-deficient cells improved in culture, but knockout mice showed limited benefit, illustrating a cell-to-animal translation gap.
Reported population / model
Mice and cell culture
Reported study details
CDKL5 KO · Various doses · In vitro efficacy, limited in vivo benefit
Reported by Pep-Pedia; the linked publication, design, doses and result have not been independently verified here.
Read the Pep-Pedia report ↗Pep-Pedia reference card; original summary of its reported findings · Checked 2026-10-12
8Synaptic Protein and Glutamate Receptor EnhancementPep-Pedia report · Primary source not checked
AI-PREPARED SUMMARY
Pep-Pedia reports: P021 increased several glutamate-receptor subunits in mouse hippocampus; these molecular endpoints do not establish clinical cognitive benefit.
Reported population / model
Mice
Reported study details
3xTg-AD · Oral P021 · Enhanced NMDA/AMPA receptor expression
Reported by Pep-Pedia; the linked publication, design, doses and result have not been independently verified here.
Read the Pep-Pedia report ↗Pep-Pedia reference card; original summary of its reported findings · Checked 2026-10-12
9Neurotrophic peptides incorporating adamantane improve learning memory neurogenesis and synaptic plasticity in micePep-Pedia report · Primary source not checked
AI-PREPARED SUMMARY
Pep-Pedia reports: A related CNTF-derived peptide improved mouse learning and neurogenesis markers; exact P21/P021 sequence identity must be checked.
Reported population / model
Mice
Reported study details
C57Bl6 · IP administration · 4 weeks · Enhanced learning, memory, and neurogenesis
Reported by Pep-Pedia; the linked publication, design, doses and result have not been independently verified here.
Read the Pep-Pedia report ↗Pep-Pedia reference card; original summary of its reported findings · Checked 2026-10-12
10Chronic oral neurotrophic peptidergic treatment in a triple transgenic mouse model of Alzheimer’s diseaseLinked reference · Not independently reviewed
REFERENCE NOTE
Reference retained from Pep-Pedia’s bibliography; findings and bibliographic accuracy have not been independently verified.
Pep-Pedia bibliography · Checked 2026-10-12
11Enhancement of neurogenesis and memory by a neurotrophic peptide in mild to moderate traumatic brain injuryPep-Pedia report · Primary source not checked
AI-PREPARED SUMMARY
Pep-Pedia reports: Parent Peptide 6 increased new-neuron counts and improved memory after mouse brain injury; the tested parent differs from P21/P021 products.
Reported population / model
Mice
Reported study details
C57Bl6 · CCI model · 50 nmol/animal/day · 30 days · Neurogenesis and memory recovery
Reported by Pep-Pedia; the linked publication, design, doses and result have not been independently verified here.
Read the Pep-Pedia report ↗Pep-Pedia reference card; original summary of its reported findings · Checked 2026-10-12
12Prevention of dendritic and synaptic deficits and cognitive impairment with a neurotrophic compoundPep-Pedia report · Primary source not checked
AI-PREPARED SUMMARY
Pep-Pedia reports: Oral P021 improved tau, BDNF and cognition measures in an Alzheimer mouse model; this does not establish equivalence with marketed P21.
Reported population / model
Mice
Reported study details
3xTg-AD · 60 nmol/g feed oral · 6-12 months · Tau reduction, BDNF increase, cognitive rescue
Reported by Pep-Pedia; the linked publication, design, doses and result have not been independently verified here.
Read the Pep-Pedia report ↗Pep-Pedia reference card; original summary of its reported findings · Checked 2026-10-12
13Alzheimer’s Disease: Challenges and a Therapeutic Opportunity to Treat It with a Neurotrophic CompoundPep-Pedia report · Primary source not checked
AI-PREPARED SUMMARY
Pep-Pedia reports: Long-term P021 exposure reduced pathology and memory deficits in transgenic mice; absence of observed animal harms is not long-term human safety evidence.
Reported population / model
Mice
Reported study details
3xTg-AD and wild-type · Oral · 18 months · Prevention of neurodegeneration
Reported by Pep-Pedia; the linked publication, design, doses and result have not been independently verified here.
Read the Pep-Pedia report ↗Pep-Pedia reference card; original summary of its reported findings · Checked 2026-10-12
14Effects of a CNTF peptide mimetic in an in vitro and in vivo model of CDKL5 deficiencyPep-Pedia report · Primary source not checked
AI-PREPARED SUMMARY
Pep-Pedia reports: CDKL5-deficient cells improved in culture, but knockout mice showed limited benefit, illustrating a cell-to-animal translation gap.
Reported population / model
Mice and cell culture
Reported study details
CDKL5 KO · Various doses · In vitro efficacy, limited in vivo benefit
Reported by Pep-Pedia; the linked publication, design, doses and result have not been independently verified here.
Read the Pep-Pedia report ↗Pep-Pedia reference card; original summary of its reported findings · Checked 2026-10-12
15Pep-Pedia: P21 — reported pharmacokineticsReference estimate; not independently verified human PKCommunity source checked
AI-PREPARED SUMMARY
Lists a half-life of 6 hrs and a peak time of 15 min. Stated attribution: Li et al. FEBS Lett 2010. This value is reported by a secondary reference. The stated attribution has not been independently verified as a route- and formulation-matched human PK measurement. Five half-lives is not complete clearance, and the source’s “cleared” value is not used as a measured endpoint.
Secondary reference page checked; the underlying quantitative claim is not independently confirmed. · Checked 2026-10-12
16Pep-Pedia: P21 — route-specific referenceReference page checked; underlying claims require separate verification.Community source checked
AI-PREPARED SUMMARY
Source page checked across available routes. Protocols, cycles, storage, mechanisms and pairing claims are secondary reports; checking the page does not independently validate those claims. Original concise summaries are used here.
Content coverage audit · Checked 2026-10-12