Peptide Research Hub
Educational reference
Educational reference only. Nothing on this site is medical advice. Many compounds described here are not FDA-approved, lack adequate human evidence, and may be illegal in your jurisdiction. Always consult a licensed clinician.

Nootropic & Neuropeptides

P21

Also known as: CNTF analog

Evidence: Preclinical only Disclaimer: Critical Not FDA-approved

Mechanism & research context

Synthetic peptide analog of ciliary neurotrophic factor (CNTF). Animal models only.

Safety flags

0 flags

No curator-recorded safety flags for this entry. Absence of recorded flags is not evidence of safety. Many peptides lack adequate human data.

Research papers

16 records

Citation links route to PubMed, Europe PMC, and PMC. Presence of a study is not endorsement. Records are refreshed from PubMed on a regular cadence; rows marked “Live search link” will resolve to a current PubMed search until a full citation has been ingested.

Clinical trials

21 records
  • Live search Live search

    Live ClinicalTrials.gov search: P21

    Condition: See live results

    Open on ClinicalTrials.gov ↗
  • NCT00099021 PHASE2 COMPLETED

    A Phase IIa Cancer Prevention Trial of the PPAR Gamma Agonist Pioglitazone in Oral Leukoplakia

    Condition: Head and Neck Cancer; Oral Leukoplakia

    Sponsor: National Cancer Institute (NCI)

    Open on ClinicalTrials.gov ↗
  • NCT00208793 PHASE2 COMPLETED

    Calcium, Vitamin D, and Colon Cancer Risk Biomarkers

    Condition: Colorectal Adenomatous Polyps

    Sponsor: Emory University

    Open on ClinicalTrials.gov ↗
  • NCT00378404 PHASE1 TERMINATED

    A Phase I Trial of Docetaxel and Low-Dose Fractionated Radiation in the Treatment of Metastatic or Recurrent Non-Small Cell Lung Cancer (NSCLC)

    Condition: Non-Small Cell Lung Cancer

    Sponsor: Susanne Arnold

    Open on ClinicalTrials.gov ↗
  • NCT00398047 PHASE2 TERMINATED

    Combination of Azacitadine and Hematopoietic Growth Factors for Myelodysplastic Syndrome

    Condition: Leukemia; Myelodysplastic Syndromes

    Sponsor: Wake Forest University Health Sciences

    Open on ClinicalTrials.gov ↗
  • NCT00470353 NA TERMINATED

    A Pilot Study of Low and High Dose Vitamin Cholecalciferol (D3) With Pharmacokinetic and Pharmacodynamic Correlates in Patients With Resected Colon Cancer

    Condition: Colorectal Cancer

    Sponsor: Roswell Park Cancer Institute

    Open on ClinicalTrials.gov ↗
  • NCT01325311 PHASE2 COMPLETED

    Phase IIA, Randomized Placebo-Controlled Trial of Single High Dose Cholecalciferol and Daily Genistein (G-2535) Versus Placebo in Men With Early Stage Prostate Cancer Undergoing Prostatectomy

    Condition: Prostate Adenocarcinoma; Stage I Prostate Cancer; Stage IIA Prostate Cancer; Stage IIB Prostate Cancer

    Sponsor: National Cancer Institute (NCI)

    Open on ClinicalTrials.gov ↗
  • NCT01344330 COMPLETED

    Cruciferous Vegetable Intake and Histone Status in Screening Colonoscopy Patients

    Condition: Colon Cancer

    Sponsor: Texas A&M University

    Open on ClinicalTrials.gov ↗
  • NCT02056691 NA COMPLETED

    Clinical and Biological Effects of a Preoperative Exercise Programme in Colorectal Tumour and Skeletal Muscle Tissues (Exercise inDuced Changes In Colorectal Cancer Tissues)

    Condition: Colorectal Cancer

    Sponsor: The Royal Bournemouth Hospital

    Open on ClinicalTrials.gov ↗
  • NCT02917629 PHASE2 TERMINATED

    Phase IIB Randomized, Placebo-Controlled Trial of ACTOplus Met® XR in Subjects With Stage I-IV Squamous Cell Carcinoma of the Oral Cavity or Oropharynx Prior to Definitive Treatment

    Condition: Oral Cavity Neoplasm; Oropharyngeal Neoplasm; Stage 0 Oral Cavity Squamous Cell Carcinoma American Joint Committee on Cancer (AJCC) v6 and v7; Stage 0 Oropharyngeal Squamous Cell Carcinoma AJCC v6 and v7; Stage I Oral Cavity Squamous Cell Carcinoma AJCC v6 and v7; Stage I Oropharyngeal Squamous Cell Carcinoma AJCC v6 and v7; Stage II Oral Cavity Squamous Cell Carcinoma AJCC v6 and v7; Stage II Oropharyngeal Squamous Cell Carcinoma AJCC v6 and v7; Stage III Oral Cavity Squamous Cell Carcinoma AJCC v6 and v7; Stage III Oropharyngeal Squamous Cell Carcinoma AJCC v7; Stage IVA Oral Cavity Squamous Cell Carcinoma AJCC v6 and v7; Stage IVA Oropharyngeal Squamous Cell Carcinoma AJCC v7; Stage IVB Oral Cavity Squamous Cell Carcinoma AJCC v6 and v7; Stage IVB Oropharyngeal Squamous Cell Carcinoma AJCC v7

    Sponsor: National Cancer Institute (NCI)

    Open on ClinicalTrials.gov ↗
  • NCT03274778 NA WITHDRAWN

    An Exploratory proof-of Mechanism Study to Assess the Effect of Ruxolitinib on Tumor Infiltrating Myeloid Cells and Additional Immune Subsets in Prostate Cancer Patients

    Condition: Prostate Cancer

    Sponsor: Oncology Institute of Southern Switzerland

    Open on ClinicalTrials.gov ↗
  • NCT03717909 PHASE2 COMPLETED

    A Pivotal, International, Randomised, Double-blind, Efficacy and Safety Trial of Sodium Valproate, in Paediatric and Adult Patients With Wolfram Syndrome

    Condition: Wolfram Syndrome

    Sponsor: University of Birmingham

    Open on ClinicalTrials.gov ↗
  • NCT03719690 PHASE2 COMPLETED

    A 2 Cohort, Non-comparative, Pivotal Study Evaluating the Efficacy of Tipifarnib in Patients With Head and Neck Squamous Cell Carcinoma (HNSCC) With HRAS Mutations (AIM-HN) and the Impact of HRAS Mutations on Response to First Line Systemic Therapies for HNSCC (SEQ-HN)

    Condition: HRAS Gene Mutation; HNSCC

    Sponsor: Kura Oncology, Inc.

    Open on ClinicalTrials.gov ↗
  • NCT03725436 PHASE1 COMPLETED

    A Phase 1b Study of ALRN-6924 in Combination With Paclitaxel in Wild-Type TP53 Advanced or Metastatic Solid Tumors Including Estrogen-Receptor Positive Breast Cancer

    Condition: Advanced Malignant Solid Neoplasm; Anatomic Stage III Breast Cancer AJCC v8; Anatomic Stage IIIA Breast Cancer AJCC v8; Anatomic Stage IIIB Breast Cancer AJCC v8; Anatomic Stage IIIC Breast Cancer AJCC v8; Estrogen Receptor Positive; HER2/Neu Negative; Metastatic Malignant Solid Neoplasm; Prognostic Stage III Breast Cancer AJCC v8; Prognostic Stage IIIA Breast Cancer AJCC v8; Prognostic Stage IIIB Breast Cancer AJCC v8; Prognostic Stage IIIC Breast Cancer AJCC v8; Recurrent Breast Carcinoma; TP53 wt Allele; Unresectable Malignant Solid Neoplasm

    Sponsor: M.D. Anderson Cancer Center

    Open on ClinicalTrials.gov ↗
  • NCT04247464 NA COMPLETED

    Evaluation of Short-term Fasting Effects on Chemotherapy Toxicity and Efficacy

    Condition: Fasting

    Sponsor: IMDEA Food

    Open on ClinicalTrials.gov ↗
  • NCT05222217 COMPLETED

    Gatekeeper™ Prostheses Implants for Patients With Gas Incontinence and Soiling

    Condition: Gas Incontinence; Soilings, Fecal

    Sponsor: Hospital Mutua de Terrassa

    Open on ClinicalTrials.gov ↗
  • NCT05252871 NA COMPLETED

    Assessment of Three Basic Progressive Lens Designs

    Condition: Presbyopia

    Sponsor: Western University of Health Sciences

    Open on ClinicalTrials.gov ↗
  • NCT05304143 NA COMPLETED

    Efficacy of Immersive Entertainement Glasses in Magnetic Resonance Imaging to Reduce Claustrofobia: Clinical Control Trial

    Condition: Claustrophobia; Magnetic Resonance Imaging (MRI)

    Sponsor: Hospital Mutua de Terrassa

    Open on ClinicalTrials.gov ↗
  • NCT05364502 NA ACTIVE_NOT_RECRUITING

    A Prospective Multicenter Single-Arm Staged Study to Evaluate the Safety and Effectiveness of Embrace™ Hydrogel Embolic For Transcatheter Embolization of Arterial Bleeding in Solid Organs and Peripheral Arteries

    Condition: Arterial Bleeding in Solid Organs and Peripheral Arteries

    Sponsor: Instylla, Inc.

    Open on ClinicalTrials.gov ↗
  • NCT05416177 UNKNOWN

    Assessment of Vivity With French Clinical Data Related to the Toric Model Study

    Condition: Cataract

    Sponsor: Versailles Hospital

    Open on ClinicalTrials.gov ↗
  • NCT05491590 COMPLETED

    Patient-reported Outcomes in Status Epilepticus Requiring Intensive Care Unit Management

    Condition: Patient Reported Outcomes; Long Term Outcomes; Status Epilepticus; Intensive Care Unit; Intensive Care Unit Syndrome

    Sponsor: Versailles Hospital

    Open on ClinicalTrials.gov ↗

Doses reported in studies

0 records
This is not a dosing guide. Entries below are historical metadata transcribed verbatim from a cited clinical-trial protocol, published study, or FDA-approved label. They describe what was administered in a specific study population under medical supervision — they are not recommendations, not common-use guidance, and may not be safe or appropriate outside the cited context. Doses widely discussed in community/anecdotal sources are not shown here; see the safety policy for why.

No study-protocol dose records have been curated for P21 yet. Absence of records is not evidence of safety — many peptides lack adequate human-trial data in the first place.

Records here are populated from public sources only (ClinicalTrials.gov protocol summaries and FDA-approved labels) and must cite a verifiable source URL. They are not added from forum posts, vendor pages, anecdotal write-ups, or social media.

These entries describe what was studied. They do not tell you what to take, how to reconstitute anything, how to fill a capsule, how often to administer, or where to obtain a compound. If you are considering use of P21, those decisions belong with a licensed clinician working from the full label or trial record — not from this summary.

Why this page does not list a dose for self-use

The "Doses reported in studies" section above (when populated) describes what was administered in a cited study or label, under medical supervision, in a specific population. It is not a dosing guide for self-use. Separately, we do not publish anecdotal or community-reported dose ranges, administration methods, vial concentrations, or capsule masses for P21. Anecdotal figures for unapproved compounds are not harm-reduction data: they lack denominators for adverse events, cannot account for individual physiology or compound purity, and normalise unsupervised use. See the safety policy for the full reasoning.

If this compound has an FDA-approved label

If a label exists, the regulator-reviewed dosing and administration information is there — read it in the context of a prescriber's evaluation.

Questions worth bringing to a clinician

  • What is the evidence for this compound in someone with my history?
  • What are the realistic, regulator-reviewed alternatives?
  • What would you monitor, and what would make you stop?

If you have already taken a peptide and feel unwell: contact emergency services. In the United States, Poison Control is reachable 24/7 at 1-800-222-1222. Do not wait for a community thread.

Research peptides are not substitutes for medical care. If you are considering any peptide for health purposes, speak with a board-certified physician or endocrinologist first.