P21

P21, also known as a CNTF‑derived or palmitoyl peptide, is a synthetic compound studied for hippocampal neurogenesis and cognitive enhancement; in community discussions it is most often taken off‑label for memory and cognitive improvement, a use reported in six posts with roughly five of them positive and a medium confidence rating. Users commonly administer about 4 mg per day (the reported span runs from 0.5 mg to 4 mg) and usually do not specify a timing or cycling schedule. The peptide lacks an FDA‑approved indication, so all human use remains off‑label or compounded, and injection‑site reactions have been noted only occasionally.

Half-life~4 h

Data last updated

ClinicalResearchDepthClinicalResearchEfficacyClinicalResearchSideEffectsno dataAnecdotalEfficacyAnecdotalSideEffectsPrice1.51.73.13.12.0

Measured on 5 of 6 axes

Research Evidence

Evidence shape

The evidence tier for P21 is animal‑only, indicating that the only available data come from preclinical or mechanistic research on a single indication. Breadth shows one indication mapped, depth indicates zero registered human trials, and quality notes no completed trials. This absence of human trial data means there is no published evidence on efficacy or safety in people, leaving the peptide’s clinical relevance unverified as reflected in the input data.

Depthhow much
1 registered trial
1 completed
Breadthhow many areas
2 indications mapped
1 thin / exploratory · 1 animal-only · 1 single-trial long-tail
Qualityhow rigorous
Highest tier: Phase 1
Breadth and depth18 rows captured
Human
direct clinical signal
1
Animal
translational support
5
In vitro
mechanistic support
12
HighMediumLow

Anecdotal efficacy

P21 side effects

Clinical research side effects

Clinical safety table not projected yet.

Anecdotal side effects

Price

Full buying guide →
1
Top Peptide
US
50 mg
$65.99
$1.32/mg
2
Raccoon Peptides
GB
10 mg
$40.13
$4.01/mg
3
OP Labs
United Kingdom
5 mg
$30.74
$6.15/mg
4
Bulk Peptide Supply
unknown
100 mg×10
$750.00
$7.5/mg
5
Tydes Peptides
USA
10 mg
$75.00
$7.5/mg
6
Peptides World
US
10 mg
$79.90
$7.99/mg

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P21 dosing & protocol

How P21 is dosed across research, clinician, and community sources — each evidence tier kept separate so the dose range, frequency, timing, and cycling stay visible without flattening different levels of evidence.

Research trials
Published clinical-trial protocols · n = 1
Typical dose
10 mg
typical
0
2 mg
4 mg
6 mg
8 mg
10 mg
single reported dose
Route
oral

One trial used 10 mg taken orally, from a single registered study.

1 source
Clinician practice
Doctor & published-protocol guidance
Typical dose
—
0
2 mg
4 mg
6 mg
8 mg
10 mg
no dose captured for this tier yet

No structured protocol details captured for this tier yet.

Anecdotal
Community-reported real-world use · n = 4
Typical dose
4 mg500 µg – 4 mg
typical
0
2 mg
4 mg
6 mg
8 mg
10 mg
distribution of 4 reported doses · darker = more
Frequency
unspecified
Route
subQ

Across four community reports, doses span 0.5 mg to 4 mg subQ; two of the four specified daily administration, while the others noted a dose without a cadence, and no cycling patterns were reported.

4 sources

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