Semax + Selank (The Nootropic Stack)

Semax and Selank are both synthetic regulatory peptides developed at the Institute of Molecular Genetics of the Russian Academy of Sciences. They are often used together because they address complementary aspects of cognitive performance — Semax enhances focus, mental clarity, and neuroplasticity, while Selank reduces anxiety and improves stress resilience without sedation. The combination is sometimes called the "Russian nootropic stack" and is the most commonly discussed peptide pairing for cognitive optimization. The rationale is that optimal cognitive performance requires both enhanced neural capacity (Semax) and reduced interference from anxiety and stress (Selank). Both are approved medications in Russia — Semax for cognitive and neurological conditions, Selank for generalized anxiety disorder.

Semax is a synthetic analog of ACTH(4-10) that enhances BDNF (brain-derived neurotrophic factor) expression, supporting neuroplasticity, synaptic strengthening, and neurogenesis. It modulates dopaminergic and serotonergic signaling and has demonstrated neuroprotective effects against oxidative stress and neurodegeneration. A 2025 study showed Semax's potential for correcting pathological impairments in Alzheimer's disease models. Selank is a synthetic analog of the immunomodulatory peptide tuftsin, modified for enhanced CNS activity. It modulates GABAergic neurotransmission, producing anxiolytic effects comparable to benzodiazepines but without sedation, tolerance, or dependence. It also has immunomodulatory properties, regulating cytokine levels under stress conditions. A functional connectomics study examined both peptides' effects on brain network connectivity, providing direct evidence that they modulate different but complementary neural circuits — Semax primarily affecting cognitive/attention networks and Selank affecting emotional regulation circuits.

Both peptides are approved medications in Russia with clinical use spanning decades, though Western clinical trial data is limited. Semax has published research demonstrating BDNF upregulation, neuroprotection in stroke models, cognitive enhancement, and antidepressant-like effects in chronic stress models (2024). A 2025 study explored its potential in Alzheimer's disease. Selank has published data on anxiolytic effects, stress-protective properties (including gut protection during chronic stress), and immunomodulatory cytokine regulation. A 2020 functional connectomics study examined both peptides' effects on brain networks simultaneously. The combination has not been studied in Western-style randomized controlled trials. Evidence comes primarily from Russian clinical use, preclinical studies, and mechanistic research. The quality and accessibility of the Russian clinical literature varies.

Both peptides are most commonly administered as nasal sprays, making them convenient for daily use. They are typically used during waking hours — Semax for cognitive-demanding periods and Selank for anxiety-provoking situations or general stress management. Some practitioners recommend cycling (e.g., 3-4 weeks on, 1-2 weeks off). Specific dosing should be determined by a qualified clinician.