P-21

P021Lyophilized powder

P-21 (P021) is a small peptidergic compound studied in preclinical rodent models of neurogenesis and memory. It has no human trials. Below: today's vial sizes, prices through our link and the vendor's COA details.

Size

$20.69/mg · Sold out at last check

Price

$103.46

List

$114.95

Buy 5 mg at Swiss Chems

Sold out at every vendor we list at last check. Compare p-21 vendors

Price shown uses code THEPEPTIDECATALOG at Swiss Chems's checkout (10% off list).

Sold by Swiss Chems. The Peptide Catalog does not sell peptides; we earn a commission if you buy through this link, at no extra cost to you. For laboratory research use only, not for human or veterinary use. Not FDA-approved. Nothing on this page is medical or dosing advice.

P-21 research vial
P-21Swiss Chems
Research use only
Certificate of AnalysisCertificates from Swiss ChemsView
  • Listed on our p-21 vendor comparison, ordered by our vendor rankings
  • Lyophilized powder · laboratory research use only
Research-context information only. P-21 is a research peptide. Protocols, doses, and reactions reported below come from published research and self-reported community sources. This article reports what has been documented, not what should be done. Consult a licensed physician for personal medical decisions.

Vial sizes listed by the vendor

P-21 Vial Sizes & Prices

P-21 vial sizes, prices and lots at Swiss Chems
SizeListWith our codePer mgAvailability
5 mg$114.95$103.46$20.69Sold out

Prices checked today, 5:05 AM CT on Swiss Chems's site, with code THEPEPTIDECATALOG applied. The lot certificate is on Swiss Chems's product page. Sizes not re-checked in the last 7 days are hidden. The vendor's checkout is final.

Test results

P-21 Certificate of Analysis

Swiss Chems publishes certificates on its own site. Match the lot number on the vial to its certificate.

View the P-21 certificate on Swiss Chems's product page.

How to check one: how to verify a peptide COA.

P-21 Dosing in Clinical Research

Neurogenesis / Cognition (Research / No Human Data)

Educational reference only. Individual responses vary. Consult healthcare provider before use.

Vial Size
5 mg lyophilized vial
Reconstitution
Reconstitute the lyophilized vial with bacteriostatic water (community practice)
Dose
500 mcg-1 mg per day — community range (broader cited ~100 mcg-2 mg)
Timing
AM (community advice to avoid sleep disruption)
Frequency
Once daily; 4-8 week cycles commonly reported
Duration
No established protocol (no human safety data)
Protocol Notes
CNTF-derived adamantylated tetrapeptide (Ac-DGGLAG-NH2 / P021; CAS 1246751-68-7). There are no human trials and no human dose — the 500 mcg-1 mg/day figures are community/vendor-derived, not trial-validated. Rodent studies used oral/peripheral dosing while community use skews subcutaneous/intranasal, a route mismatch worth noting. The literature is clean of integrity flags but entirely preclinical. Sold for research purposes only.

Why This Dosing Protocol

What dose do people use? There is no clinically-established human dose — no human trial has defined one. The figures community and vendor sources actually use cluster around 500 mcg to 1 mg once daily(broader cited range ~100 mcg-2 mg/day), with new users commonly pointed toward the lower end (~250-500 mcg). These are microgram-to-low-milligram figures — far below Dihexa's milligram community range — and every one is anecdotal/vendor-derived, not from human pharmacokinetic data.

Form and route. Swiss Chems lists P21 as a 5 mg lyophilized vial, so community use involves bacteriostatic-water reconstitution like a standard injectable peptide. Community sources most often describe subcutaneous injection (intranasal is also mentioned), dosed in the morning, in 4-8 week cycles. Note rodent efficacy was shown with oral/peripheral dosing — a route mismatch worth flagging.
Full Dosing GuideReconstitution Calculator

How P-21 Works

CNTF-Derived Adamantylated Tetrapeptide — Neurogenic / Neuroprotective (Preclinical Evidence Only; No Human Trials)

Target → Signal → Effect → Outcomes

1
Target

CNTF-Active-Region Tetrapeptide → BDNF Cascade — Proposed

P-21 (P021) is a synthetic adamantane-modified tetrapeptide — Ac-DGGLAG-NH2(CAS 1246751-68-7) — derived from the active region of ciliary neurotrophic factor (CNTF), residues 148-151. It was developed in Khalid Iqbal's lab by paring Cerebrolysin's neurotrophic activity down to a single defined molecule (Li et al., 2010, PMID 20600002). The adamantane moiety was added to improve metabolic stability and blood-brain-barrier penetration. Although CNTF-derived, the reported procognitive effect runs largely through a BDNF-mediated cascade rather than classical CNTF receptor signaling.

2
Cellular Signal

↑BDNF, ↑phospho-CREB, ↓GSK-3β — Preclinical

In rodent and in-vitro models, P021 is reported to enhance dentate-gyrus neurogenesis and synaptic plasticity by inhibiting leukemia inhibitory factor (LIF) signaling and increasing BDNF transcription, with a downstream decrease in GSK-3β activity and increased phospho-CREB (PMID 28368015). Downstream effects in models include reduced tau pathology, preserved synaptic markers, and improved maze learning. All of this is preclinical — no human mechanistic or pharmacokinetic data exists.

3
Systemic Effect

Disease-Modifying in Rodent Models — Not Humans

The P-21 evidence base is a coherent, largely single-lab body of rodent work (~2010-2019). Chronic oral P021 reduced age-dependent cognitive decline in aged rats (PMID 24702821), produced disease-modifying effects in 3xTg-AD Alzheimer's mice including a reported survival increase (PMID 25046994), and rescued deficits in a Ts65Dn Down syndrome model (PMID 28368015). It is consistent in direction and clean of integrity flags — but it is rodent disease/aging-model data, not human cognitive-enhancement data. "Disease-modifying in a mouse model" is not "works in people."

4
What You Notice

Unknown in Humans

There are no human trials of P-21, so there is no evidence base for predicting what a person would notice. Community reports (anecdotal) describe subtle cognitive/mood or focus changes over days to a few weeks, but they are mixed and inconsistent — some describe noticeable effects, others little or nothing, and a subset describe overstimulation or sleep disruption at higher or later-day doses. None of this is placebo-controlled or verified.

What Makes This Peptide Different

P-21's evidence is the opposite kind of limited from Dihexa's: it is clean of retractions and integrity flags, but it is entirely preclinical and mostly from one originating lab, with zero human trials, no human safety, dose, or pharmacokinetic data, and no FDA approval for any indication. Unlike the Dihexa HGF/c-Met oncology discussion, there is no specific cancer-pathway literature tying P-21 to malignancy. It is sold strictly as a research chemical, not for human consumption.

Technical specifications

P-21 chemical & analytical data

Also known as
P021
Form
Lyophilized (freeze-dried) powder in a sealed vial
Presentation
5 mg
Regulatory status
Research peptide; research-grade vials are not FDA-approved.

Storage & Handling

Storage at a glance

Proper storage temperatures, shelf life, reconstitution best practices, and travel tips for lyophilized and reconstituted peptides.

Powder: Freezer
1+ year at -20°C
Reconstituted: Fridge
4 weeks max at 2-8°C
View Complete Storage Guide

Handling specifics

Educational overview on storage, labeling, and traceability considerations for lab environments. Consult primary literature and vendor documentation for specifics.

Powder storage (very stable)
  • Freezer (-20°C): 1+ year
  • Refrigerator (2-8°C): 1-3 months
  • Room temperature: 2-3 weeks (emergency only)
Reconstituted storage (fragile)
  • MUST refrigerate at 2-8°C
  • 4-week maximum shelf life
  • NEVER freeze after reconstitution
  • Use bacteriostatic water for multi-dose

8 answers

P-21 FAQ: Buying, COA, Storage & Research

What is P-21 (P021)?
A synthetic adamantane-modified tetrapeptide (Ac-DGGLAG-NH2; CAS 1246751-68-7) derived from the active region of ciliary neurotrophic factor (CNTF). It was developed in Khalid Iqbal's lab by paring Cerebrolysin's neurotrophic activity down to a single defined molecule. It is studied for neurogenesis and tau reduction in rodent Alzheimer's models and is sold as a research chemical, not for human consumption.
Does P-21 have human clinical trials?
No. There are no published human clinical trials of P-21, and no trials are registered on ClinicalTrials.gov. All evidence is preclinical (rodent and in-vitro). There is no human safety, dose, or pharmacokinetic data. No retractions or integrity flags were found in the P-21 literature — a genuine difference from Dihexa, whose foundational papers were retracted.
Is there an established dose for P-21?
There is no clinically-established human dose — no human trial has defined one. The figures community and vendor sources actually use cluster around 500 mcg to 1 mg once daily (broader cited range ~100 mcg-2 mg/day), typically subcutaneous or intranasal. Those numbers are anecdotal and vendor-derived, not trial-validated.
What does the preclinical research show?
In rodent models, chronic P021 was reported to enhance neurogenesis, increase BDNF, reduce tau pathology, preserve synaptic markers, and improve maze learning — in aged rats (PMID 24702821), a 3xTg-AD Alzheimer's model (PMID 25046994), and a Ts65Dn Down syndrome model (PMID 28368015). These are animal disease/aging models, not human cognitive-enhancement data, and the work is largely from one originating lab.
What side effects are reported?
There is no human safety data. The most consistent anecdotal complaint is sleep disruption or overstimulation, especially at higher doses or evening dosing — the basis for the common "dose in the morning" community advice. Headache and irritability are mentioned occasionally. Reports are inconsistent, and rodent toxicology is not comprehensively published. Decisions about a compound with no human safety profile are matters for a licensed physician.
How long does reconstituted peptide last?
Once mixed with bacteriostatic water, peptides remain stable for up to 4 weeks when refrigerated at 2-8°C (36-46°F). Unopened powder can last 1+ year in the freezer. Get our complete Storage & Travel Guide.
Is this peptide legal to purchase?
Peptides sold "for research purposes only" are legal to purchase in the US, but are not FDA-approved for human use outside of specific medical applications. Always consult a healthcare provider before use.
New to peptides?
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P-21 Research Articles

dosing

P-21 Dosage: What the Community Reports

P-21 has no trial-set dose. See the 500 mcg-1 mg figure community sources actually use, the route mismatch, and the all-rodent evidence behind it.

side-effects

P-21 Side Effects: The No-Human-Data Reality

P-21 has zero human safety data — every figure is preclinical or anecdotal. The sleep-disruption signal and theoretical cautions, graded by source.

results

P-21 Timeline: What the Evidence Shows

No human trial sets a P-21 timeline. Here's the gap between rodent chronic-dosing data and community-reported onset, each clearly labeled.

reconstitution

P-21 Reconstitution: 5mg Vial Bac Water Math

P-21 ships as a 5mg lyophilized vial with no validated human dose. Here's the bac-water math community sources use for the ~500mcg-1mg subQ range.

Compare P-21 Vendors Before You Buy

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