Cognitive
Semax / Selank
Synthetic peptides developed in Russia and studied for cognitive and anxiety-related effects.
Where the evidence comes from
78 verified records from 6 countries. The number of studies or countries is not proof that Semax / Selank works or is safe.
Other: 3 · Animal study: 65 · Narrative review: 4 · Human clinical trial: 2 · Observational human study: 3 · Randomized clinical trial: 1
What is known
Editorial summary not yet written.
What remains uncertain
Editorial summary not yet written.
Conflicting findings
Editorial summary not yet written.
U.S. regulatory status (FDA)
Compound
Product or formulation
FDA status
FDA-approved branded drug
Approved indication
Metara availability (compounded formulation)
Research material (research use only)
Source
Last verified
Notes
Approval applies only to the exact finished drug, formulation and indication. A shared active ingredient does not make a compounded version, blend or other use FDA-approved. Pharmacy or research-material availability is not FDA approval.
International regulatory status
Kept separate from U.S. status. The regulator's country is not the same as where studies took place.
No sourced international decisions recorded yet.
Continue your research
These are two different pathways, not two ways to get the same thing. Neither changes the FDA status shown above.
Clinical care
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Most human studies are small and published in Russian journals.
Human clinical evidence (6)
Comparing the Efficacy of tDCS and tRNS to Improve Reading Skills in Children and Adolescents With Dyslexia
Bambino Gesù Hospital and Research Institute · ClinicalTrials.gov · NCT05832060
This registered human trial was designed to compare two forms of electrical brain stimulation with sham stimulation for improving reading skills in children and adolescents with dyslexia. Its status is unknown, and the abstract presents expected benefits and safety as hypotheses rather than results.
Semax, a Synthetic Regulatory Peptide, Affects Copper-Induced Abeta Aggregation and Amyloid Formation in Artificial Membrane Models.
Sciacca MFM, Naletova I, Giuffrida ML, Attanasio F · ACS chemical neuroscience · DOI 10.1073/pnas.95.11.6448
This lab study tested how Semax affected amyloid-beta clumping and copper interactions in artificial membrane models and laboratory assays, not in people. Semax prevented amyloid-beta–copper complexes from forming and showed anti-clumping and protective properties, especially when copper was present. The findings suggest that Semax inhibits amyloid fiber formation by interfering with these complexes.
Functional Connectomic Approach to Studying Selank and Semax Effects.
Panikratova YR, Lebedeva IS, Sokolov OY, Rumshiskaya AD, Kupriyanov DA, Kost NV, Myasoedov NF · Doklady biological sciences : proceedings of the Academy of Sciences of the USSR, Biological sciences sections · DOI 10.1134/S001249662001007X
This human study used resting-state brain scans to examine Selank and Semax effects in healthy participants compared with placebo. Researchers identified shared and distinct effects on functional connectivity, meaning coordinated brain activity, between the right amygdala and the right temporal cortex.
Effects of Semax on the Default Mode Network of the Brain.
Lebedeva IS, Panikratova YR, Sokolov OY, Kupriyanov DA, Rumshiskaya AD, Kost NV, Myasoedov NF · Bulletin of experimental biology and medicine · DOI 10.1007/s10517-018-4234-3
This human study used resting-state brain scans to compare healthy volunteers receiving Semax or placebo. The Semax group showed a greater volume of the medial frontal component of the brain's default mode network than controls. The study demonstrated the location of Semax-related effects on this brain network.
[Optimization of the treatment of anxiety disorders with selank].
Medvedev VE, Tereshchenko ON, Kost NV, Ter-Israelyan AY, Gushanskaya EV, Chobanu IK, Sokolov OY, Myasoedov NF · Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova · DOI 10.17116/jnevro20151156133-40
This human study compared phenazepam alone with selank plus phenazepam in people with anxiety disorders. The combined treatment produced an earlier therapeutic effect on the HDRS rating scale and reduced several phenazepam side effects during treatment and after withdrawal. The authors reported a positive impact on quality of life.
Modulating Behavior in Humans by Entrainment With Rhythmic Transcranial Magnetic Stimulation
National Institute of Neurological Disorders and Stroke (NINDS) · ClinicalTrials.gov · NCT01747200
This completed human study investigated whether transcranial magnetic stimulation could alter brain rhythms and interfere with recognizing pictures of familiar objects in healthy adults. The abstract describes brain-wave monitoring and recognition tests, but reports no results.
Systematic & narrative reviews (4)
Modulation of neuropathological pathways by bioactive peptides and proteins/polypeptides: Targeting oxidative stress in neurodegenerative diseases.
Giri S, Chandra P · Neuropeptides · DOI 10.1016/j.npep.2025.102563
This review examined peptides and proteins, including Semax, in preclinical studies and early human trials of neurodegenerative diseases. It reports effects on oxidative stress, inflammation, cellular energy systems, and nerve-cell connections. The authors highlight potential protective benefits but emphasize delivery challenges and the need for further clinical validation.
Sigmoidal maximal effect modeling of low-density lipoprotein cholesterol concentration and annual incidence of coronary heart disease events in secondary prevention trials.
Charland SL, Stanek EJ · Pharmacotherapy · DOI 10.1002/phar.1368
This analysis used published human cardiovascular trial data to model the relationship between LDL cholesterol and coronary death or nonfatal heart attack. The best-fitting model projected diminishing reductions in these events as LDL cholesterol fell to lower levels. It studied cholesterol and statins, not the Semax peptide.
[Evolution of the stress concept].
Sudakov KV · Vestnik Rossiiskoi akademii meditsinskikh nauk · PMID 19140465
This review discussed theories of emotional stress, brain signaling, and peptides including Semax; the abstract does not specify human or animal study populations. It describes these peptides as factors that increase resistance to stress and emphasizes individual differences in stress tolerance.
Selank and short peptides of the tuftsin family in the regulation of adaptive behavior in stress
· DOI 10.1023/a:1025988519919
This animal study compared Selank and related tuftsin-family peptides in male rats and mice exposed to a stressful conflict situation. The peptides showed positive emotional and anti-stress effects. Individual effects varied with the peptides' molecular structures or their breakdown products.
Laboratory, animal & other research (68)
Semax, a Copper Chelator Peptide, Decreases the Cu(II)-Catalyzed ROS Production and Cytotoxicity of aβ by Metal Ion Stripping and Redox Silencing.
Tomasello MF, Di Rosa MC, Naletova I, Sciacca MFM, Giuffrida A, Maccarrone G, Attanasio F · Bioinorganic chemistry and applications · DOI 10.1039/c9mt00045c
This lab study examined Semax in copper–amyloid-beta reactions and cultured SH-SY5Y cells. Semax removed copper from amyloid-beta complexes, altered their chemical cycling, and reduced production of reactive oxygen molecules. The cell findings suggest that Semax has protective properties against oxidative stress caused by copper-driven amyloid-beta oxidation.
Genes That Associated with Action of ACTH-like Peptides with Neuroprotective Potential in Rat Brain Regions with Different Degrees of Ischemic Damage
Filippenkov IB, Shpetko YY, Ales DA, Stavchansky VV, Denisova AE, Yuzhakov VV, Fomina NK, Gubsky LV, Andreeva LA, Myasoedov NF, Limborska SA, Dergunova LV · International journal of molecular sciences · DOI 10.3390/ijms26136256
This animal study examined how Semax and another ACTH-like peptide affected gene activity in rat brain regions after an experimentally induced stroke. Both peptides tended to normalize disrupted gene activity, but effects differed by brain region. The other peptide also worsened some gene-activity disturbances in the striatum, mainly involving inflammation.
The Potential of the Peptide Drug Semax and Its Derivative for Correcting Pathological Impairments in the Animal Model of Alzheimer's Disease.
Radchenko AI, Kuzubova EV, Apostol AA, Mitkevich VA, Andreeva LA, Limborska SA, Stepenko YV, Shmigerova VS, Solin AV, Korokin MV, Pokrovskii MV, Myasoedov NF · Acta naturae · DOI 10.32607/actanaturae.27808
This animal study tested Semax and a derivative in genetically modified mice used as a model of Alzheimer's disease. Both peptides improved cognitive function in behavioral tests and reduced amyloid deposits in the cortex and hippocampus.
Semax peptide targets the μ opioid receptor gene Oprm1 to promote deubiquitination and functional recovery after spinal cord injury in female mice.
Liu R, Chen Y, Huang H, Li X, Lv J, Jiang L, Jiang H, Wu C, Chen W, Xu H, Zhu Z, Cai H · British journal of pharmacology · DOI 10.1111/bph.70122
This animal and lab study examined Semax in female mice with spinal cord injury and in a cell model of nerve inflammation. Semax improved functional recovery in mice and reduced oxidative stress and inflammatory cell death in the models. The findings linked these effects to opioid receptors and a pathway that removes molecular tags from proteins.
The Effect of Peptide Semax, an ACTH(4-10) Analogue, on Intracellular Calcium Dynamics in Rat Brain Neurons
Kolbaev SN, Sharonova IN, Skrebitsky VG · Bulletin of experimental biology and medicine · DOI 10.1007/s10517-025-06501-z
This lab study examined Semax’s effects on calcium signals in nerve cells within rat brain slices. Semax increased the frequency of spontaneous calcium fluctuations in hippocampal cells but did not significantly affect acid-triggered calcium increases in cerebellar cells. The findings suggest its protective mechanism is not related to reducing calcium entry through acid-sensing channels in those cerebellar cells.
Antidepressant-like and antistress effects of the ACTH(4-10) synthetic analogs Semax and Melanotan II on male rats in a model of chronic unpredictable stress
Inozemtseva LS, Yatsenko KA, Glazova NY, Kamensky AA, Myasoedov NF, Levitskaya NG, Grivennikov IA, Dolotov OV · European journal of pharmacology · DOI 10.1016/j.ejphar.2024.177068
This animal study tested Semax and Melanotan II in male rats exposed to chronic unpredictable stress. Both peptides reversed or reduced loss of pleasure-seeking behavior, suppressed weight gain, adrenal enlargement, and reductions in a brain protein involved in nerve-cell support. Neither peptide changed immobility in the forced-swim test.
Changes of Transcriptomic Activity in Rat Brain Cells under the Influence of Synthetic Adrenocorticotropic Hormone-Like Peptides.
Filippenkov IB, Glazova NY, Sebentsova EA, Stavchansky VV, Andreeva LA, Myasoedov NF, Levitskaya NG, Limborska SA, Dergunova LV · Biochemistry. Biokhimiia · DOI 10.1134/S0006297924090104
This animal study examined gene activity in the frontal brain region of rats given Semax or a related ACTH-like peptide under normal conditions. Both peptides mainly reduced activity of immune-related genes. Differences between their effects involved genes linked to nerve signaling and ion-channel regulation.
Selank, a Peptide Analog of Tuftsin, Attenuates Aversive Signs of Morphine Withdrawal in Rats
Konstantinopolsky MA, Chernyakova IV, Kolik LG · Bulletin of experimental biology and medicine · DOI 10.1007/s10517-022-05624-x
This animal study tested Selank in morphine-dependent rats whose withdrawal was triggered by naloxone. Selank reduced overall withdrawal signs, including convulsive reactions, drooping eyelids, and posture problems, and raised the threshold for responding to touch. Its effects were slightly weaker than those of diazepam.
Browse worldwide evidence → · Search and filter all Semax / Selank studies →
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Profile last reviewed September 26, 2026. Educational content only. Not medical advice, a dosing protocol or a treatment recommendation.