What's on the label is the measured result — net peptide mass, not gross powder weight, plus RP-HPLC purity, on a lot-numbered COA for every batch.
Net peptide mass and RP-HPLC purity — a lot-numbered COA for every batch.
Net peptide mass + HPLC purity, per lot.
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CNTF-derived neurogenic tetrapeptide with adamantane moiety
PeptideXpo buyer fit
This PeptideXpo page is intentionally positioned for distributors, OEM buyers, and procurement teams comparing P21 (P021) inside a wider peptide catalog. It is not trying to be the deepest single-molecule monograph; the differentiated intent is assortment planning, export-ready documentation, fill-size comparison, and whether this SKU belongs in a broader buyer program.
Overview
P21 (also designated P021 or Peptide 6c in some publications) is a synthetic peptidergic compound (Ac-DGGLAG-NH2) derived from ciliary neurotrophic factor (CNTF), built around the active tetrapeptide core Asp-Gly-Gly-Leu (DGGL) with a C-terminal adamantylated glycine that provides oral bioavailability and blood-brain-barrier penetration. The molecule was developed at the New York State Institute for Basic Research as a small-molecule mimetic of CNTF's neurogenic and BDNF-upregulating effects without CNTF's known dose-limiting side-effect profile. P21 is studied in research contexts for adult hippocampal neurogenesis, BDNF expression, and Alzheimer's disease and aging-related cognitive decline models. PeptideXpo supplies P21 as a lyophilized powder at ≥99.0% HPLC purity. The adamantane modification creates analytical challenges similar to other lipidated peptides, the modified molecule is substantially more hydrophobic than the unmodified DGGL tetrapeptide and requires modified RP-HPLC conditions for adequate resolution. The release packet covers peak-integration HPLC under appropriate conditions, mass spec confirming the adamantane-modified mass, and water content. The 5 mg fill size matches typical neuroscience-research aliquot scales.
Who buys this, and why
Cognitive and neuropeptide buyers are predominantly research labs running in vivo rodent studies. The dominant administration route in the literature is intranasal, these peptides are not meaningfully blood-brain-barrier permeable when delivered systemically. For in vivo workflows, endotoxin and microbial-limit testing is recommended at the COA stage so the bioassay readout is not confounded by contamination unrelated to the test article.
Primary buyer fit: academic and contract research laboratories.
Specifications
Documentation available on request
Regulatory note
Research peptide derivative; CAS is not consistently registered across suppliers. Sold for research use only.
Frequently asked questions
The unmodified DGGL tetrapeptide is too polar for both oral absorption and blood-brain-barrier penetration, properties that would make it useless for CNS research. The adamantane group at the N-terminus provides three things: (1) increased overall hydrophobicity that supports passive membrane diffusion, (2) protection against aminopeptidase cleavage, and (3) sufficient blood-brain-barrier permeability that systemic administration produces meaningful CNS exposure. The adamantane is a delivery vehicle rather than a pharmacophore, the biological activity comes from the DGGL peptide sequence, but the modification is essential for the molecule to reach its target tissue at functional concentrations.
CNTF (Ciliary Neurotrophic Factor) is a 200-amino-acid cytokine in the IL-6 family with strong neurotrophic and neurogenic activity in CNS research models. Native CNTF advanced through clinical trials for ALS in the 1990s and was discontinued due to severe off-target side effects (weight loss, fever, antibody formation) that came from the cytokine's broad receptor-binding profile. The P21 design strategy isolated a tetrapeptide (DGGL) from a specific region of CNTF hypothesized to drive the neurogenic activity, then added the adamantane group for delivery, producing a small molecule that retains some of CNTF's neurogenic effects without the cytokine's full receptor-binding profile and associated side effects. P21 is therefore a research tool for studying CNTF-mimetic biology in isolation from the broader cytokine pharmacology.
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