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Lexicon
Cognition

P21-Adamantane

The adamantane-stabilized form of the neurogenic peptide P21, meant for a longer duration.

2 min read 6 sources

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Vial with white powder, a blue cap and a black TPD label for P21-Adamantane on a white podium, next to it a molecule chain of blue and white glass spheres with a compact ring group at one end in a bright lab
Preclinical · not approved

Summary

At a glance

Sources checked on 26 Oct 2026

Core from CNTF
4 amino acids

plus a glycine with an adamantane group, as in the studied P0213

Longest dosing in the Alzheimer model
12 months

Mice received P021 with their food, tau changes declined1

Studies on a separate adamantane variant
0 studies

all data concern P021, which already contains the adamantane2

Human trials in the registry
0 trials

no trial with P021 on ClinicalTrials.gov, as of 26 Oct 20266

  • P21-Adamantane is listed as a stabilised form of the peptide P21. However, the P21 studied in research, called P021 there, already carries the adamantane itself: a glycine with an adamantane group at the end.23
  • The core of four amino acids comes from the most active region of the nerve growth factor CNTF. The adamantane is meant to slow breakdown and ease the way into the brain.3
  • In Alzheimer mice a year of dosing with the food reduced abnormal tau changes. Memory and formation of new nerve cells improved.1
  • Old rats lost less learning and memory performance with P021. The peptide reached the brain and lowered tau in the cerebrospinal fluid.54
  • ClinicalTrials.gov lists no human trial (as of October 2026). Everything here is preclinical research, not a recommendation.6
Profile

Updated May 2026

Class
CNTF-derived neurogenic peptide

stabilized

Use
Subcutaneous

in mcg

Half-life
longer than P21

adamantylated

Status
Preclinical

no human data

Sizes
10 mg

1 size in the shop

Contents 15 sections
  1. At a glance
  2. What is P21-Adamantane?
  3. How it works
  4. What you need
  5. Reconstitution
  6. Dosing
  7. Injection
  8. What the research shows
  9. Research status
  10. Side effects
  11. Storage
  12. Related compounds
  13. FAQ
  14. Glossary
  15. Sources

What is P21-Adamantane?

P21-Adamantane is the adamantane-stabilized variant of the neurogenic peptide P21 (P021), which you also find individually in the lexicon. The attached adamantane makes the molecule more lipophilic and more resistant to breakdown, which extends the duration.

Up front: purely preclinical, no human data.

Comparison

Other peptides focused on the brain

Rough classification by origin. Tap a card to open its entry.

Listed as a stabilised form P21-Adamantane BDNFGSK-3β
CNTF derivative with adamantane (P021) P21 BDNFGSK-3β ACTH(4-7) derivative Semax Spadin derivative PE 22-28

P21 and P21-Adamantane rest on the same studies of P021. The origin of the other peptides is described in their lexicon entries.

How it works

Like P21 it is derived from an active section of the nerve growth factor CNTF and is meant to promote the formation of new nerve cells and memory, among other things via raising BDNF. The adamantyl group is a pharmacological modification for more stability.

Details on the mechanism are in the P21 entry.

Where it acts

Where P021 acted in experiments

Tap a point or a card. All from cell and animal studies with P021.

  1. Brain (hippocampus)

    More BDNF, less GSK-3β activity and abnormal tau, more new nerve cells (mice, rats)1

    BDNFGSK-3β

Known targets1

Compound P021, Ac-DGGL(A)G-NH2 (nicht in PubChem oder ChEMBL): two described targets, type of action on each card.

Neurotrophic factor BDNF
Gene
BDNF
UniProt
P23560
ChEMBL
CHEMBL4523205
Action
Production increased, not a direct binding target
Glycogen synthase kinase 3β
Gene
GSK3B
UniProt
P49841
ChEMBL
CHEMBL262
Action
Activity lowered, probably via more BDNF
Glowing network of glass nerve cells, small blue molecules resting on two branches
Meant to promote the formation of new nerve cells, partly through more BDNF. Symbolic image.

What you need

Supplies

2 things, numbered as in the picture

Tick off what you already have. Vial and BAC water are our real shop photos at the same size.

P21-Adamantane vial and bacteriostatic water at the same size with the black TPD label, next to two U-100 insulin syringes, two alcohol swabs and a sharps container with a blue lid

  1. P21-Adamantane vial

    The P21-Adamantane vial (lyophilized powder).

    In the shop

  2. Water and supplies

    Bacteriostatic water, U-100 insulin syringes, alcohol swabs.

    In the shop

Reconstitution

Use the peptide calculator. A 10mg vial with 2ml water gives 5mg per ml. Just add the water to the vial and let it dissolve.

Step by step

Dissolving the powder

Four steps, the same for every vial size.

  1. 1Wipe the cap

    Clean the rubber stopper with an alcohol swab.

  2. 2Add BAC water

    Just add it, it does not matter if it hits the powder directly.

  3. 3Swirl or shake

    Until everything has dissolved, both are fine.

  4. 4Draw up

    With the U-100 insulin syringe.

Less water higher concentration fewer units on the syringe Example: 10 mg + 2 ml = 5 mg/ml

Dosing

Dosing

Dosing, titration and syringe

Loading the dosing information …

  • Getting started and stepping up, drawn as a staircase
  • Units on the U-100 syringe for every step
  • How long one vial lasts

Injection

The injection is subcutaneous, into the fat layer under the skin. Common spots are the abdomen (keep about two finger-widths clear of the navel), the front and the inner side of the thigh, or the back of the upper arm.

The short version:

Injection

Where and at what angle

Pick a spot or switch the angle. Subcutaneous means: into the fat layer, not the muscle.

Rotate the spot each time, never the same one twice in a row.

90°More fat under the skin

Rule of thumb: where there is more fat under the skin, insert straight at 90 degrees. In lean people with little fat, 45 degrees, so the needle stays in the fat layer. Simplified diagram.

  1. Clean the spot with an alcohol swab and let it dry

  2. Pinch up a small fold of skin

  3. Insert the needle: at 90 degrees where there is more fat under the skin, at 45 degrees in lean people with little fat

  4. Inject slowly, wait a moment, then withdraw

  5. Put the needle straight into the sharps container

Rotate the site each time so the tissue does not get irritated. Never the same spot twice in a row.

What the research shows

The basis is the same as P21 (Kazim, 2014): oral P021 favorably influenced disease progression in an Alzheimer's mouse model. The adamantyl modification targets longer duration. There are no standalone human studies on P21-Adamantane, it is clearly experimental.

Top view of petri dishes, a pipette and a small hourglass around a glass seahorse
The hippocampus is named after its seahorse shape. Symbolic image.

Research status

Where the research stands

What has been studied is P021 with its adamantane group, in cells, mice and rats, almost only by the group at the New York State Institute for Basic Research. As of 26 Oct 2026. 6

  1. Preclinical Cell assays, Alzheimer mice, old rats
  2. Phase 1 no registered trial
  3. Phase 2 no registered trial
  4. Phase 3 no registered trial
  5. Approval not yet
Not approved and no registered human trial. P021 has only been studied preclinically so far.6

So far there is no registered trial in humans. 6

Side effects

  • Solid human data are missing.
  • Local reactions at the injection site.

Storage

Before mixing the powder is robust, normal room temperature (around 20 to 25 degrees) is fine, ideally kept in the dark. After mixing, keep in the fridge (2 to 8 degrees), do not freeze. It stays good there for at least 4 to 6 months with barely any loss of potency, in practice considerably longer. Swirl or shake to mix, both are fine.

Shelf life

How long it keeps

Undissolved (powder) Room temperature, around 20 to 25 degrees, dark

Robust, no fridge needed.

Dissolved (mixed) Fridge, 2 to 8 degrees, do not freeze

At least 4 to 6 months with barely any loss of potency.

  • Keep it dark
  • Dissolved: 2 to 8 degrees
  • Note the mixing date on the vial
Nine vials with white powder and blue caps in the door shelf of a bright fridge
Powder dark at room temperature, once dissolved into the fridge (2 to 8 degrees), stable there for at least 4 to 6 months. Symbolic image.

Related

Related compounds

Blends with P21-Adamantane or a different path: all in the TPD lexicon.

P21-Adamantane
P21 Same body of research, P021 already carries the adamantane Semax Different short peptide focused on the brain PE 22-28 Different peptide, new nerve cells in mice Dihexa Different molecule linked to memory in research Pinealon Short peptide from the Khavinson programme, brain

FAQ

Common questions about P21-Adamantane

Short answers, each backed by the sources below.

Is P21-Adamantane approved or studied in humans?

No. There is no approval and as of 26 October 2026 ClinicalTrials.gov lists no trial with P021. All data come from cells and animals.6

How does P21-Adamantane differ from P21?

According to the literature, nothing that has been shown. The very first paper from 2010 described P21 as a peptide with adamantane. Later papers call it P021: a tetrapeptide from CNTF plus a glycine with an adamantane group at the end. A further, longer-acting adamantane variant is not described in any study.23

What is the adamantane for?

It is meant to get the peptide through the blood-brain barrier more easily and protect it from enzymes that cut peptides from the end. In old rats P021 did reach the brain.34

What did the Alzheimer models show?

Mice with three Alzheimer genes received P021 with their food for twelve months. Abnormal tau declined clearly, soluble amyloid fell, memory and the formation of new nerve cells improved. When dosing started early, the changes largely did not appear.13

What did old rats show?

Rats aged 22 to 24 months lost less learning and memory performance with P021 and made more BDNF. The tau level in the cerebrospinal fluid fell to that of young rats.54

Which side effects are known?

There are no solid data because P021 has never been tested in humans. In old rats it caused no detectable immune reaction. That cannot be transferred to humans.46

Glossary

Terms explained briefly

Dotted words in the text open these explanations directly.

Adamantane
A small cage-like hydrocarbon scaffold. On peptides it is meant to slow breakdown and ease the way into the brain.
BDNF
Brain-derived neurotrophic factor: a growth factor in the brain, important for synapses, learning and new nerve cells.
Blood-brain barrier
A tight wall of the brain's blood vessels that keeps many substances in the blood out.
CNTF
Ciliary neurotrophic factor: the body's own growth factor that keeps nerve cells alive. P021 is derived from its most active region.
Lipophilic
Fat-loving. Lipophilic substances dissolve better in fat and pass cell membranes more easily.
Lyophilisate
Freeze-dried powder. Without water a peptide keeps much longer.
Neurogenesis
Formation of new nerve cells. In adults it mainly takes place in the hippocampus.
Preclinical
Research before first use in humans, in cell cultures and animal models. Results cannot be transferred directly to humans.
Subcutaneous
Into the fat layer just under the skin.
Tau
A protein that supports the scaffold of nerve cells. In Alzheimer's it is excessively phosphorylated and clumps together.

Evidence

Sources

Show all 6 sourcesHide sources 5 Studies1 Trial registry checked 26 Oct 2026

Studies

  1. P021 over one year in an Alzheimer mouse model

    Kazim et al., Neurobiology of Disease, 2014

    DOI 10.1016/j.nbd.2014.07.001 PMID 25046994
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  2. First paper on P21: peptides with adamantane and memory in mice

    Li et al., FEBS Letters, 2010

    DOI 10.1016/j.febslet.2010.06.025 PMID 20600002
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  3. Structure of P021 and early dosing in an Alzheimer model

    Baazaoui und Iqbal, Alzheimer's Research and Therapy, 2017

    DOI 10.1186/s13195-017-0273-7 PMID 28655344
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed, PMC (Volltext)
  4. P021 reaches the brain and lowers tau in the cerebrospinal fluid of old rats

    Khatoon et al., Journal of Alzheimer's Disease, 2015

    DOI 10.3233/JAD-142799 PMID 26401692
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  5. P021 slows memory loss in old rats

    Bolognin et al., Neurobiology of Aging, 2014

    DOI 10.1016/j.neurobiolaging.2014.02.017 PMID 24702821
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed

Trial registry

  1. Search on ClinicalTrials.gov (no trial with the peptide)

    ClinicalTrials.gov, U.S. National Library of Medicine

    Checked 26 Oct 2026 via ClinicalTrials.gov API v2

In the shop

P21-Adamantane in the catalog

Sizes, prices and shipping times are on the product page.

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