PubMed
Ciliary neurotrophic factor (CNTF) and related peptides in neuroprotection
Peterson et al., 2013
Neurological & CognitiveResearch OnlyD
P21
Nootropic Peptide Candidate
Experimental neurocognitive peptide candidate with limited human evidence.
Observational report only — live community data. Not medical advice. Does not recommend doses, protocols, or treatments.
- Studies cited
- 3
- Research grade
- D
- Experience
- 100
- Activity
- 84
Overall check-ins
Trackers & reports
Overview
About P21
Experimental neurocognitive peptide candidate with limited human evidence.
- Category
- Neurological & Cognitive
- Regulatory status
- Research Only
- Also known as
- Nootropic Peptide Candidate
- Self-reports
- 6
Community
What 6 users report
6 community reports
Overall experience
From check-in ratings — separate from side effects logged below. Side effects are logged separately from overall experience. A favorable check-in can still include nausea, fatigue, or injection-site reactions.
Favorable 100% · Mixed 0% · Unfavorable overall 0%
Most reported benefits
Benefits users selected when logging a favorable or mixed check-in.
Cognition
6
Mood
6
Sleep
3
Self-reported dose per injection
Median bucket: 200–400 mcg · Most common: 200–400 mcg
Reports span 100–400 mcg
100–200
2
200–400
4
Anonymized self-reports from PeptIQ users — not prescribing guidance. Buckets group similar logged amounts; open-ended top buckets mean “at least” that dose.
Commonly stacked with
Research
Cited research (2)
Source
PubMed
The effect of exogenous ciliary neurotrophic factor on cell cycle and neural differentiation markers of in vitro model cells: New insights for future therapeutic approaches
Ghasemi et al., 2021
Tools
Explore more
Explore
More ways to learn about P21 from observational PeptIQ data.
Compare with
Related peptides
Help
Frequently asked
What do PeptIQ users report about P21?
This page summarizes 6 anonymized self-reports from PeptIQ users who track P21, including commonly reported effects and co-tracked peptides. These are observational patterns, not clinical outcomes.
How do side effects relate to overall experience for P21?
PeptIQ separates overall check-in ratings (favorable, mixed, or unfavorable) from logged side effects like nausea or fatigue. Users often report benefits and side effects in the same check-in — a high experience score does not mean zero side effects were noted.
What research is cited for P21?
2 sources are linked on this page, including PubMed articles, clinical trial registries, and FDA labels where applicable. Citations describe published research — not recommendations.
Is P21 safe to use?
This wiki does not assess safety or recommend use. P21 is listed as Research Only. Consult a licensed clinician for personal medical decisions.
What are the purported benefits and uses of P21?
Research, primarily in animal models, suggests P21 may have a wide range of therapeutic potentials due to its ability to promote angiogenesis (formation of new blood vessels), stimulate collagen synthesis, and modulate inflammatory responses.
SourceWhat is the legal status of P21?
P21 is not approved by the FDA for any human use. There is no legal basis for selling it as a drug, food, or dietary supplement in the United States. The FDA has classified P21 as a Category 2 bulk drug substance, which explicitly prohibits licensed compounding pharmacies from using it in compounded medications.
SourceWhat are the known or theoretical side effects and risks of P21?
The safety and effectiveness of P21 have not been thoroughly evaluated in humans through rigorous clinical trials. This lack of human data means that safe dosages, short-term side effects, and long-term health consequences are largely unknown.
SourceWhat is the current state of research on P21?
While there are over 200 published studies on P21, the vast majority are animal or in vitro (cell) studies. These preclinical studies consistently show positive results across various tissue types. However, there is a significant lack of comprehensive human clinical trial data.
Source