Cognitive Function Peptides

Supports brain function and cognition

Primary Use

Cognitive peptides target brain function through several pathways: increasing brain-derived neurotrophic factor (BDNF, a protein that supports the growth and survival of neurons), modulating neurotransmitter systems, reducing neuroinflammation, and improving cerebral blood flow. The most researched include semax and selank (synthetic analogs of naturally occurring brain peptides), dihexa (an angiotensin IV analog with potent effects on memory formation), and cerebrolysin (a mixture of neurotrophic peptides used clinically in some countries for stroke and traumatic brain injury).

Interest in cognitive peptides comes from both clinical neurology (treating brain injuries, neurodegeneration, and cognitive decline) and the nootropic community (optimizing mental performance in healthy individuals). The evidence base ranges from extensive clinical trial data (cerebrolysin has hundreds of studies) to early-stage research with mostly animal data (dihexa).

This page collects every peptide on PeptideWiki tagged for cognitive function. Browse individual profiles for mechanisms, dosing protocols, and safety information.

Peptides (8)

Semax

Cognition, Mood & Neuroprotection

Semax is a synthetic peptide derived from a brain hormone fragment (ACTH 4-10), developed in Russia for brain-protective and cognitive-enhancing purposes. Research focuses on stroke recovery, cognitive function, and brain growth factor support.

Selank

Cognition, Mood & Neuroprotection

Selank is a synthetic seven-amino-acid peptide derived from the immune protein tuftsin, developed in Russia. Research shows it has both immune-supporting and anti-anxiety properties without causing sedation or dependence.

Dihexa

Cognition, Mood & Neuroprotection

Dihexa is a synthetic six-amino-acid peptide related to angiotensin IV with strong cognitive-enhancing properties. It has been proposed to be millions of times more potent than natural brain growth factors at promoting nerve cell connections. Research focuses on cognitive enhancement and neurodegenerative diseases.

Cerebrolysin

Cognition, Mood & Neuroprotection

Cerebrolysin is a preparation derived from pig brain tissue containing small brain-protective peptides and amino acids. It is approved in many countries (but not the United States) for stroke, traumatic brain injury, and dementia. It is one of the most extensively studied brain peptide formulations.

Glutathione

Longevity & Cellular Health

Glutathione is a three-amino-acid peptide made naturally in every cell from glutamate, cysteine, and glycine. It neutralizes damaging molecules, supports mitochondrial energy production, and helps the liver process toxins. Levels fall with age and chronic illness, making it a widely studied target for antioxidant and anti-aging research.

PE-22-28

Cognition, Mood & Neuroprotection

PE-22-28 is a synthetic seven-amino-acid peptide designed to block a specific potassium channel (TREK-1) in the brain. Research in animal models focuses on antidepressant-like effects and cognitive enhancement through brain growth factor support and increased brain cell adaptability.

Pinealon

Cognition, Mood & Neuroprotection

Pinealon is a synthetic three-amino-acid peptide that may help regulate pineal gland and central nervous system function. Developed in Russia, research focuses on sleep regulation, brain cell protection, and cognitive function in aging.

Cortagen

Cognition, Mood & Neuroprotection

Cortagen is a synthetic four-amino-acid peptide that may help regulate brain cortex function. Developed at the St. Petersburg Institute of Bioregulation and Gerontology, research focuses on supporting cognitive function in aging and protecting brain cells.

Frequently Asked Questions

The primary mechanism for many cognitive peptides is increasing BDNF, a growth factor that helps neurons form new connections and strengthens existing ones. Semax raises BDNF levels significantly within hours of administration. Selank modulates GABA (the brain's main calming neurotransmitter) and reduces anxiety, which indirectly improves focus and cognitive clarity. Dihexa enhances the activity of hepatocyte growth factor in the brain, which promotes synapse formation. Cerebrolysin contains fragments of neurotrophic factors that directly support neuron survival and plasticity.

Most clinical research focuses on impaired populations (stroke recovery, Alzheimer's, traumatic brain injury). Data on cognitive enhancement in healthy individuals is limited. Anecdotal reports from the nootropic community describe improved focus, verbal fluency, and memory with semax and selank, but controlled studies in healthy subjects are scarce. The practical question is risk vs. reward: these compounds carry some unknowns, and healthy brains may have less room for improvement compared to impaired ones.

Selank has been specifically studied for this and shows no dependence or withdrawal effects in available research. Semax similarly does not appear to be habit-forming. Neither acts on dopamine reward pathways the way stimulants do. Dihexa and cerebrolysin also do not show addictive properties. However, long-term safety data for most cognitive peptides in healthy users is limited, so cycling protocols are commonly recommended.

Semax and selank are typically administered as intranasal drops or sprays, which allows them to cross the blood-brain barrier more efficiently. Cerebrolysin is given as an intramuscular or intravenous injection in clinical settings. Dihexa is available as an oral capsule in research contexts. PE-22-28 and pinealon are usually subcutaneous injections. The route of administration matters because the blood-brain barrier blocks many peptides from reaching the brain when injected subcutaneously.

Semax is often considered the starting point because it has the most human clinical data among nootropic peptides, a well-characterized safety profile, intranasal administration (no injections), and noticeable effects within hours. It was developed in Russia and has been used clinically there since the 1990s for stroke recovery and cognitive support. Selank is a common companion for those seeking anxiety reduction alongside cognitive benefits.

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