NovaWell.
P22 research vial
Sequence length
6 AA
Molecular weight
~742 g/mol (1-Ad-CO-DGGLAG-NH2)
Current batch
P22202604
Nootropics · Neurotrophic peptide research / structure-activity comparator to P21

P22

Adamantane-modified analog of P21 with a notably negative published research record

P22 (10mg vials)

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Specifications

Molecular weight~742 g/mol (1-Ad-CO-DGGLAG-NH2)
Sequence length6 amino acids
Amino acid sequence1-Ad-CO-Asp-Gly-Gly-Leu-Ala-Gly-NH2
AppearanceWhite lyophilized powder
SolubilityBacteriostatic water; sterile water; may require mild acidification for full solubility
Storage (lyophilized)-20°C, protected from light
Storage (reconstituted)2–8°C, use within 28 days
Half-lifeNot characterized in published Western literature
Current batch purity99.43% (HPLC) · P22202604

P22 is a short synthetic hexapeptide designed as a structural analog of P21, both originating from the Iqbal / Grundke-Iqbal research group at the New York State Institute for Basic Research. P22 has the sequence 1-Ad-CO-DGGLAG-NH2 — the same DGGLAG core as P21, but with an adamantane carbonyl group at the N-terminus instead of the smaller N-acetyl group used in P21. Researchers evaluating P22 should be aware that the Western peer-reviewed literature specifically on this compound is extremely limited — effectively a single primary paper (Li et al., FEBS Letters, 2010), in which P22 was included as a structure-activity comparator to P21 and produced largely negative results. We have not identified independent in vivo replication of P22 in the indexed English-language literature beyond that paper. P22 is supplied by NovaWell as a lyophilized powder, third-party tested for purity and endotoxin conformance, for laboratory research use only.

Research Studies

The following study is summarized for educational purposes only. Inclusion does not imply any human use; all referenced research was conducted in animal models. Note that this is, to our knowledge, the only primary peer-reviewed paper in the Western literature in which P22 itself (as distinct from its parent compound P21) was directly tested.

Research study

Neurotrophic peptides incorporating adamantane improve learning and memory, promote neurogenesis and synaptic plasticity in mice

Li B, Wanka L, Blanchard J, Liu F, Chohan MO, Iqbal K, Grundke-Iqbal I. FEBS Lett. 2010 Aug 4;584(15):3359–3365. doi:10.1016/j.febslet.2010.06.025 View source ↗

Scientific findings

This study introduced two adamantane-modified hexapeptide derivatives — P21 (Ac-DGGLAG-NH2 with C-terminal 3-aminoadamantane-1-carboxylic acid) and P22 (1-Ad-CO-DGGLAG-NH2, in which an adamantanecarbonyl group replaces the smaller N-acetyl group at the N-terminus). The compounds were administered peripherally to adult mice and evaluated in the Morris water maze, novel object recognition, and histological assessments of hippocampal neurogenesis and synaptic protein expression. P21 produced statistically significant improvements across multiple endpoints, including spatial learning probe trials, object recognition preference, increased hippocampal progenitor proliferation, and elevated synaptophysin and synapsin I expression. P22, in contrast, did not reach statistical significance on probe-trial spatial memory or on the novel-object preference index. The authors suggested that the bulky N-terminal adamantane moiety in P22 likely interfered with proper interaction of the active DGGL subsequence with its biological target, and presented P22 primarily as a structure-activity counterexample establishing the importance of the smaller N-acetyl group in P21. To our knowledge, P22 has not been the primary subject of a subsequent independent in vivo study indexed in the Western peer-reviewed literature.

Plain English

Researchers built two related peptides, P21 and P22, that share the same six-amino-acid core but differ in what is attached to one end. P21 worked: mice given P21 learned faster on a swimming maze, paid more attention to new objects, grew more new brain cells in the hippocampus, and showed increases in proteins associated with the connections between brain cells. P22, on the other hand, did not produce a statistically significant improvement on the harder memory tests, and the authors concluded that the larger chemical group on P22's end probably got in the way of the molecule fitting its target. In other words, in the only published comparison of the two, P22 was the negative control that helped explain why P21 works. Researchers should weigh this carefully: P22's published record is small, and the headline result for it is "did not work as well as P21" rather than positive findings of its own.

A Direct Note on the Research Base

We want to be unusually direct about P22's evidence base, because it matters for how a research group should plan an experiment around this compound:

  • Single primary paper. Li et al. 2010 is the only English-indexed primary research paper we have identified that directly tested P22 in vivo. Most secondary mentions of P22 in catalogs and articles trace back to this one paper.
  • The headline result for P22 in that paper was negative. P22 did not reach statistical significance on the main memory endpoints. It is properly understood as a structure-activity comparator that helped establish why P21 works, not as a compound with independent positive evidence.
  • No human data. There are no controlled human efficacy data on P22 in PubMed-indexed Western journals. P22 is not approved by the FDA, EMA, or any major national regulatory body for any indication.
  • Vendor pages should not be treated as evidence. Vendor and aggregator pages that describe P22 in positive language (including, for context, pages from sources such as pepacorn.com that researchers may encounter while comparing suppliers) generally do not introduce new primary data; they restate or extrapolate from the same Li et al. paper.

Researchers planning work with P22 should design experiments accordingly — for example, as a structure-activity control alongside P21, or as a chemistry/handling reference — rather than as an extension of an established positive efficacy literature.

Storage & handling

Lyophilized (unreconstituted): Store at -20°C, protected from light. Stable for 24+ months under correct storage. Avoid repeated temperature cycling.

Reconstituted: Dissolve in bacteriostatic water (typically 1–2 mL per 10 mg vial, depending on the research protocol). The adamantane modification can reduce aqueous solubility relative to plain peptide; mild warming, vortexing, or a small amount of acidification may be required. Store reconstituted solution at 2–8°C and use within 28 days. Do not freeze reconstituted solution.

Vial format: 10 mg lyophilized, vacuum-sealed glass vial with rubber stopper and aluminum crimp. Sterility tested per USP guidelines.

Shipping: Lyophilized P22 is stable at ambient temperature for the typical 1–3 day shipping window. Cold-pack shipping available on request.

Frequently asked questions

What is P22?+

P22 is a short synthetic hexapeptide with the sequence 1-Ad-CO-DGGLAG-NH2 — the same DGGLAG core as P21, but with an adamantanecarbonyl group at the N-terminus in place of P21's smaller N-acetyl group. It was introduced by Li and colleagues at the New York State Institute for Basic Research in a 2010 FEBS Letters paper as a structure-activity counterpart to P21, originally derived from work on a CNTF (ciliary neurotrophic factor)-related sequence called Peptide 6c.

What are the limitations of the P22 research literature?+

The research literature on P22 is, candidly, very thin. We have identified one primary English-indexed paper (Li et al., FEBS Letters, 2010) that directly tested P22 in vivo, and in that paper P22 did not reach statistical significance on the main spatial-memory or novel-object-recognition endpoints. The authors used P22 chiefly as evidence that the N-terminal modification matters — i.e., as a negative control that illuminated why P21 works. We have not identified an independent in vivo replication of P22 in the indexed Western literature beyond that paper, and there are no controlled human efficacy data. Researchers should plan experiments with these limitations explicitly in mind rather than assume an established positive efficacy base.

How is P22 related to P21?+

P21 and P22 are sister molecules introduced in the same 2010 paper. They share an identical six-amino-acid core (DGGLAG) and an identical C-terminal adamantane modification; they differ only in the group attached to the N-terminus. P21 carries a small N-acetyl group (Ac-DGGLAG-NH2 with C-terminal aminoadamantane carboxylic acid). P22 carries a much bulkier 1-adamantanecarbonyl group at the same position. In the head-to-head behavioral and histological comparison reported by the authors, P21 produced significant cognitive and neurogenic effects in mice; P22 largely did not. The published interpretation is that the bulkier N-terminal group on P22 sterically interfered with target engagement.

What does NovaWell test P22 for?+

Every batch of P22 supplied by NovaWell is tested by an independent third-party laboratory for: identity and purity (HPLC + MS), bacterial endotoxin (USP <85>), heavy metals (USP), and sterility (USP). The Certificate of Analysis for the currently shipping batch is linked from the Certificates tab on this page, along with the test date, manufacturer ID, and the independent laboratory that performed the analysis. Because P22 is a niche, low-volume compound, batches may be smaller and produced less frequently than for our high-volume catalog items; please check the COA date on the listing before ordering.

How should P22 be stored after reconstitution?+

Once reconstituted in bacteriostatic water, P22 should be stored at 2–8°C and used within 28 days. Do not freeze reconstituted solution. The lyophilized 10 mg vial is stable at -20°C for 24+ months when kept protected from light and free from repeated temperature cycling. Because the adamantane modification can reduce aqueous solubility, researchers sometimes warm the vial briefly or add a small amount of acidified diluent during reconstitution; this is a handling note, not a manufacturing instruction.

Where does NovaWell source P22, and how is it manufactured?+

P22 is produced for NovaWell by a contract peptide manufacturing partner using standard solid-phase peptide synthesis with an N-terminal adamantanecarbonyl modification step. Crude peptide is purified by preparative reverse-phase HPLC to a target purity of 99%+, lyophilized, and vialed in an ISO-certified cleanroom. Each batch is third-party tested by an independent analytical lab; we publish the Certificate of Analysis for the shipping batch on this page. Given the very limited primary research base on P22, we treat it as a structure-activity research material rather than as a routine catalog peptide, and we are explicit with researchers that the supply-chain controls are what we are confident about — not a body of positive efficacy data.