Semax P-21
- Status
- Preclinical, , not approved for human use
- Evidence
-
Not graded on a research bench yet
Semax P-21 is a hybrid synthetic peptide combining structural motifs from Semax and P-21 into a single molecule. Marketed as a one-shot drop-in for users running both compounds, the rationale is convenience (one peptide instead of two) and additive cognitive + anxiolytic effects.
Reviewed
01Overview
What Semax P-21 is
The peer-reviewed literature on this specific hybrid is essentially absent — most pharmacological characterization is by analogy to the constituent peptides. Treat it as Semax-equivalent on cognition and P-21-equivalent on anxiolysis until stronger primary data emerges.
How it works
Important framing: "Semax P-21" is not a single characterized compound. It is a speculative user stack combining two separate, unrelated peptides - Semax and P-21 (P021). No pharmacological study of the combination exists, so the profile below is inferred from each constituent individually.
Read the full mechanismShow less
Semax (primary effects): A synthetic ACTH(4-7) analog that increases BDNF and NGF expression, modulates dopaminergic and serotonergic signaling, and supports attention and neuroprotection. Semax has documented clinical use in Russia.
P-21 / P021 (primary effects - animal data only): P021 is a ciliary neurotrophic factor (CNTF)-derived small-molecule peptide mimetic (Ac-DGGL(A)G-NH2). It enhances hippocampal (dentate gyrus) neurogenesis and increases BDNF expression by inhibiting the leukemia inhibitory factor (LIF) signaling pathway, and it reduces tau hyperphosphorylation through a BDNF-mediated decrease in GSK-3-beta (a major tau kinase) activity. These effects have been demonstrated only in cell and rodent models (PMID: 27400746).
Correction: Earlier claims that P-21 acts via GABA-A modulation or NGF upregulation were inaccurate - that anxiolytic/GABAergic profile belongs to the Selank/Semax family, not to P021. BDNF upregulation and neurogenesis are the intended primary effects of these peptides, not "side effects."
02Research
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03Safety
Semax P-21 side effects and interactions
Side effects
Low riskStop use if
- Pregnancy/lactation
- Active mania
- Peptide allergy
Common
- Mild nasal irritation
- Brief alertness spike
Less common
- Headache at high doses
Interactions
Not in our record
This interaction data is compiled from published research and community reports. It may not be exhaustive. Always consult a healthcare professional before combining compounds.
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04Dosing
Free with emailSemax P-21 dosage and protocols
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- Beginner, intermediate and advanced protocols
- Stacking notes
- Additional dosage notes
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05Prices
Semax P-21 prices
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06Chemistry
Chemistry and structure
- Molecular formula
- C40H58N14O11
- Molecular mass
- Not a single molecule - "Semax P-21" is two separate peptides, so no combined molecular weight applies. Per constituent: Semax (heptapeptide, Met-Glu-His-Phe-Pro-Gly-Pro) is approximately 813.9 g/mol; P-21 / P021 (Ac-DGGL(A)G-NH2, a CNTF-derived peptide mimetic) is a low-molecular-weight, blood-brain-barrier-permeable small molecule.
- Amino acid sequence
- Semax: Met-Glu-His-Phe-Pro-Gly-Pro (MEHFPGP) - ACTH(4-7) extended with a C-terminal Pro-Gly-Pro. P-21 / P021: Ac-DGGL(A)G-NH2, an N-acetylated, C-amidated peptide mimetic derived from the active region (Peptide-6) of ciliary neurotrophic factor (CNTF). These are two distinct peptides, not one sequence.
- Half-life
- No combined-product pharmacokinetics exist. Semax (intranasal): the intact peptide is rapidly metabolized (on the order of minutes), though downstream BDNF/neurotrophic effects outlast the peptide itself. P-21 / P021: a small molecule with pharmacokinetics suitable for oral dosing in animal studies; no human PK data.
08Questions
Frequently asked questions
What is Semax P-21 used for in research?
Semax P-21 is a hybrid synthetic peptide combining structural motifs from Semax and P-21 into a single molecule. Marketed as a one-shot drop-in for users running both compounds, the rationale is convenience (one peptide instead of two) and additive cognitive + anxiolytic effects.
The peer-reviewed literature on this specific hybrid is essentially absent — most pharmacological characterization is by analogy to the constituent peptides. Treat it as Semax-equivalent on cognition and P-21-equivalent on anxiolysis until stronger primary data emerges.
What forms does Semax P-21 come in?
Semax P-21 is available in vials, capsules, and sprays forms.
How much does Semax P-21 cost?
BodyHackGuide tracks no vendor for Semax P-21 yet, so no price is stated.
How do I compare Semax P-21 vendors?
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