Both are synthetic heptapeptides from the Institute of Molecular Genetics of the Russian Academy of Sciences, both carry the same Pro-Gly-Pro stabilising tail, and both are approved nasal medicines in Russia. The difference is the core: Selank is built on tuftsin and studied for anxiety, while Semax comes from ACTH(4-10), drives BDNF and is used after ischemic stroke.
Key parameters side by side
Parameter
Selank
Semax
Molecular weight
751.88 Da
813.93 Da
Same for both: Category — Cognitive & Nootropic; Evidence status — Approved; Sequence length — 7
Frequently asked questions
By origin and target. Selank is a derivative of the immunomodulatory peptide tuftsin, described as anxiolytic without sedation. Semax is built from the ACTH(4-10) fragment and acts mainly through potent BDNF upregulation and melanocortin receptor signalling.
Both are approved in Russia and most of their clinical data comes from there. Selank has a randomised comparison against the benzodiazepine medazepam in anxiety; Semax has clinical studies of recovery after acute ischemic stroke.
Cognitive & Nootropic
Selank
Approved
Selank is a synthetic heptapeptide anxiolytic developed at the Institute of Molecular Genetics of the Russian Academy of Sciences. It is based on the naturally occurring immunomodulatory peptide tuftsin (Thr-Lys-Pro-Arg) with an additional Pro-Gly-Pro sequence attached at the C-terminus. This extension dramatically enhances metabolic stability while adding nootropic and anxiolytic properties not present in native tuftsin.
Approved in Russia as an anxiolytic and nootropic medication (nasal spray formulation, 0.15% solution), selank represents one of the few peptide-based anxiolytics with formal clinical approval in any jurisdiction. It exerts its effects without the sedation, cognitive impairment, or dependence associated with benzodiazepines — making it a fundamentally different class of anti-anxiety compound.
Selank modulates the GABAergic, serotonergic, and dopaminergic neurotransmitter systems while simultaneously providing immunomodulatory benefits through its tuftsin core. This dual neurotropic-immunomodulatory profile is unique among anxiolytic compounds and has generated significant interest in Western neuropharmacology research.
Semax is a synthetic heptapeptide nootropic derived from the ACTH(4-10) fragment, developed at the Institute of Molecular Genetics of the Russian Academy of Sciences. Like selank, it features the Pro-Gly-Pro C-terminal stabilizing extension, but its core sequence is derived from adrenocorticotropic hormone (ACTH) rather than tuftsin, giving it a distinct pharmacological profile focused on cognitive enhancement and neuroprotection.
Approved in Russia as a prescription-only nootropic and neuroprotective medication (0.1% and 1% nasal spray solutions), semax is one of the few peptide-based cognition enhancers with regulatory approval anywhere in the world. It is used clinically for stroke recovery, cognitive impairment, optic nerve atrophy, and peptic ulcer disease.
Semax exerts its effects through robust BDNF upregulation, modulation of serotonin and dopamine neurotransmission, and direct neuroprotective mechanisms. Unlike ACTH itself, semax has no steroidogenic activity — it does not stimulate cortisol production, making it a purely neurotropic peptide.
Selank is a synthetic heptapeptide anxiolytic developed at the Institute of Molecular Genetics of the Russian Academy of Sciences. It is based on the naturally occurring immunomodulatory peptide tuftsin (Thr-Lys-Pro-Arg) with an additional Pro-Gly-Pro sequence attached at the C-terminus. This extension dramatically enhances metabolic stability while adding nootropic and anxiolytic properties not present in native tuftsin.
Approved in Russia as an anxiolytic and nootropic medication (nasal spray formulation, 0.15% solution), selank represents one of the few peptide-based anxiolytics with formal clinical approval in any jurisdiction. It exerts its effects without the sedation, cognitive impairment, or dependence associated with benzodiazepines — making it a fundamentally different class of anti-anxiety compound.
Selank modulates the GABAergic, serotonergic, and dopaminergic neurotransmitter systems while simultaneously providing immunomodulatory benefits through its tuftsin core. This dual neurotropic-immunomodulatory profile is unique among anxiolytic compounds and has generated significant interest in Western neuropharmacology research.
Semax is a synthetic heptapeptide nootropic derived from the ACTH(4-10) fragment, developed at the Institute of Molecular Genetics of the Russian Academy of Sciences. Like selank, it features the Pro-Gly-Pro C-terminal stabilizing extension, but its core sequence is derived from adrenocorticotropic hormone (ACTH) rather than tuftsin, giving it a distinct pharmacological profile focused on cognitive enhancement and neuroprotection.
Approved in Russia as a prescription-only nootropic and neuroprotective medication (0.1% and 1% nasal spray solutions), semax is one of the few peptide-based cognition enhancers with regulatory approval anywhere in the world. It is used clinically for stroke recovery, cognitive impairment, optic nerve atrophy, and peptic ulcer disease.
Semax exerts its effects through robust BDNF upregulation, modulation of serotonin and dopamine neurotransmission, and direct neuroprotective mechanisms. Unlike ACTH itself, semax has no steroidogenic activity — it does not stimulate cortisol production, making it a purely neurotropic peptide.