Cognitive / focus peptides
Neuropeptides studied for cognition, mood, and neuroprotection; human evidence varies and is often limited.
S is approval-grade evidence; F is documented harm or near-zero human data. Each bar is how many peptides on this page land in that tier — a fast read on how much of this category sits in approval-grade evidence versus thin or vendor-driven claims.
The category at a glance
Every compound here ranked S–F by its weighted evidence score — strongest human / approval-grade evidence at the top, thin or vendor-driven claims at the bottom. Tap any row for the evidence read. Popularity never raises a tier.
Receipts, not vendor theater. Every tier here is computed from published evidence and regulatory status — not vendor marketing or influencer claims. See how we score.
DsemaxEarly human evidenceMedium overstatementResearch-use-only41/ 100
A heptapeptide nootropic with regional (Russian) clinical use and some human studies for stroke and cognition, but limited high-quality Western trials and no FDA approval. Real history of use; evidence base is thin by current standards.
Tier read: early human evidence · medium overstatement risk · low search interest · Early human. Why not F: supported by its overall evidence profile. Why not C: held back by human evidence, safety clarity, regulatory clarity, practical relevance.
Read the full semax profile →DselankEarly human evidenceMedium overstatementResearch-use-only41/ 100
A synthetic heptapeptide derived from the immune peptide tuftsin, developed in Russia as an anxiolytic with reported nootropic effects. Human evidence is limited and largely confined to Russian-language studies (e.g. comparison with a benzodiazepine in anxiety); not approved in the US or EU.
Tier read: early human evidence · medium overstatement risk · low search interest · Early human. Why not F: supported by its overall evidence profile. Why not C: held back by human evidence, safety clarity, regulatory clarity, practical relevance.
Read the full selank profile →Fn-acetyl-semax-amidateEarly human evidenceMedium overstatementResearch-use-only29/ 100
A chemically modified (acetylated/amidated) analogue of Semax intended for greater metabolic stability. No PubMed-indexed study evaluates the modified derivative specifically; evidence for the parent Semax is predominantly Russian and preclinical/early-clinical, with no rigorous Western trials of the modified form.
Tier read: early human evidence · medium overstatement risk · low search interest · Mechanism. Why not D: held back by human evidence, preclinical depth, safety clarity, regulatory clarity, practical relevance.
Read the full n-acetyl-semax-amidate profile →FdihexaWeak human evidenceHigh overstatementResearch-use-only15/ 100
A small, orally active angiotensin-IV-derived peptide that potentiates the HGF/c-Met system, promoting synaptogenesis in the hippocampus. All evidence is preclinical (rodent and cell models) — no completed human trials, and some foundational work in this area has faced scrutiny.
Tier read: weak human evidence · high overstatement risk · low search interest · Mechanism. Why not D: held back by human evidence, preclinical depth, safety clarity, regulatory clarity, practical relevance.
Read the full dihexa profile →Cognitive and focus peptides — semax, selank, dihexa — are popular as nootropics but have a thin, largely regional evidence base. Much of the human research originated in Russia and hasn't been widely replicated in rigorous Western trials.
What the evidence actually supports
Semax (an ACTH-fragment derivative) and selank (a tuftsin analog) are studied for cognition, mood, and neuroprotection, partly via BDNF and related pathways. Dihexa is a potent HGF/c-Met activator studied for synaptogenesis — but in animal models, and it's highly experimental.
Where the hype outruns the data
Proven nootropic benefit in healthy adults, treatment of cognitive disorders, and long-term safety are not established for these compounds. Potent growth-factor signaling (dihexa) raises theoretical risks with no human safety data.
FAQ
Do nootropic peptides improve focus?
Evidence is early and largely regional; proven benefit in healthy adults isn't established.
Is dihexa safe?
It's early experimental research with no human safety data — treat it as speculative.
Is this medical advice?
No — research reference only.
Research reference only. Not medical advice, dosing, or a recommendation to use any compound. “Worth watching” ≠ proven or safe.