Brain and focus
Cognitive Peptides
Cognitive peptides are often marketed for focus, mood or neuroprotection, but the evidence base is uneven and often regional. The strongest claims need careful source checking.
- Peptides covered
- 7
- Highest evidence
- 3/5
- Approved entries
- 0
How to compare this category
Use this category hub to compare Selank and Semax by route, evidence score, mechanism and the gap between regional use and broadly validated human data.
- Distinguish regional clinical history from large independent randomized trials.
- Check whether the outcome is anxiety, neuroprotection, cognition or a broader marketing claim.
- Be careful with nootropic claims when the evidence is mainly mechanistic or preclinical.
Evidence scale
Scores rate evidence quality for the listed research context. They are not recommendations, prescriptions or a safety ranking.
- Evidence 1/5
- Mechanistic rationale only; no meaningful outcome evidence.
- Evidence 2/5
- Mostly animal, ex vivo, cell, or indirect evidence.
- Evidence 3/5
- Limited human pharmacology or small clinical evidence.
- Evidence 4/5
- Investigational compound with human randomized or phase 2/3 evidence.
- Evidence 5/5
- Approved medication with substantial human clinical evidence.
| Peptide | Status | Evidence | Best for | Half-life | Actions |
|---|---|---|---|---|---|
| Selank Synthetic tuftsin analog | Research only | 3/5 Limited human and mechanistic evidence | Anxiolytic and stress-response research context Limited human and mechanistic evidence | Minutes | |
| Semax Synthetic ACTH analog | Research only | 2/5 Mostly preclinical neuroprotection evidence | Neuroprotection and ACTH-fragment research context Mostly preclinical evidence for broad consumer claims | Minutes | |
| Cortexin Animal-derived polypeptide neuroprotective bioregulator (brain peptide hydrolysate) | Research only | 2/5 low certainty (mostly Russian-language evidence, high risk of bias) | General category comparison See detail page for context. | Not established; as a multi-component peptide hydrolysate it has no well-characterized human elimination half-life | |
| N-Acetyl Semax Synthetic ACTH(4-7)-derived melanocortin neuropeptide (acetylated/amidated Semax analog) | Research only | 2/5 Weak (analog-specific evidence essentially absent) | General category comparison See detail page for context. | Not established for the analog; parent Semax plasma half-life is only minutes due to rapid aminopeptidase degradation, and vendor-claimed multi-hour half-lives lack peer-reviewed human PK data | |
| N-Acetyl Selank Synthetic tuftsin-derived heptapeptide analog (anxiolytic neuropeptide) | Research only | 2/5 Preclinical / limited clinical for parent compound; research-only analog | General category comparison See detail page for context. | Not validated for the analog. Parent Selank has a very short plasma half-life (on the order of minutes); N-terminal acetylation and C-terminal amidation are intended to slow enzymatic degradation, but no peer-reviewed human pharmacokinetic data exist for N-Acetyl Selank. | |
| P21 CNTF-derived neurotrophic peptide mimetic | Research only | 2/5 Preclinical only (animal evidence, no human trials) | General category comparison See detail page for context. | Not established in humans; preclinical reports describe plasma stability exceeding 3 hours and high gastric/intestinal stability. | |
| Davunetide ADNP-derived microtubule-stabilizing neuroprotective peptide | Investigational | 2/5 Weak / negative pivotal evidence | General category comparison See detail page for context. | Short; preclinical estimates of roughly 15 minutes in brain after intranasal dosing. Human pharmacokinetics were not characterized in the pivotal PSP trial. |
Cognitive peptide cards
Selank
TP-7
Anxiolytic and stress-response research context
Limited human and mechanistic evidence
Semax
ACTH(4-10) analog
Neuroprotection and ACTH-fragment research context
Mostly preclinical evidence for broad consumer claims
Cortexin
polypeptide cortical fraction
Cortexin is a low-molecular-weight polypeptide fraction from animal cerebral cortex proposed to act as a multi-target neuroprotectant by modulating glutamate (AMPA, kainate, mGluR) and GABA-A receptors, inhibiting brain caspase-8, and influencing neurotrophic and antioxidant pathways.
Animal-derived polypeptide neuroprotective bioregulator (brain peptide hydrolysate)
N-Acetyl Semax
N-Acetyl Semax Amidate, NA Semax
It is a chemically stabilized analog of the ACTH(4-7)-derived peptide Semax that, in preclinical models, binds specifically in brain tissue and raises BDNF and other neurotrophins while modulating ischemia-related inflammatory and neurotransmitter gene expression.
Synthetic ACTH(4-7)-derived melanocortin neuropeptide (acetylated/amidated Semax analog)
N-Acetyl Selank
NA Selank Amidate
N-Acetyl Selank is a chemically stabilized (N-acetylated, C-amidated) analog of the tuftsin-derived peptide Selank, proposed to act via GABAergic modulation, inhibition of enkephalin-degrading enzymes that raises endogenous enkephalins, and BDNF-related effects, though these mechanisms were demonstrated for the parent Selank rather than the analog.
Synthetic tuftsin-derived heptapeptide analog (anxiolytic neuropeptide)
P21
P021, CNTF-derived peptidergic compound
P21 is a CNTF-derived peptide that increases BDNF expression, competitively inhibits leukemia inhibitory factor signaling, raises phosphorylated CREB and lowers GSK-3 beta activity to promote dentate gyrus neurogenesis and synaptic plasticity in animal models.
CNTF-derived neurotrophic peptide mimetic
Davunetide
NAP, AL-108, CP201
Davunetide binds microtubule end-binding proteins to promote microtubule stability and the tau-microtubule interaction, reducing tau hyperphosphorylation in preclinical models.
ADNP-derived microtubule-stabilizing neuroprotective peptide
Cognitive guides
Read the strongest related guides for this category before drilling into a single database entry.
FAQ
What are cognitive peptides?
Cognitive peptides are neuropeptides or peptide analogs discussed for mood, focus, anxiety or neuroprotection. Evidence quality varies by compound and claim.
Is Selank better studied than Semax?
In this database, Selank has a slightly higher evidence score because it has small clinical comparison literature plus mechanistic work, while Semax claims rely more heavily on preclinical neuroprotection evidence.
Are cognitive peptides approved in the United States?
The cognitive peptides listed here are treated as research-only for US consumer purposes and do not have approved US indications.
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