Semax and Selank are frequently mentioned in the same breath — both are stabilized heptapeptides developed through Russian neuropharmacology programs, both carry the same Pro-Gly-Pro stabilizing tail, and both are staples of preclinical neuroscience catalogs. But their research profiles diverge sharply.
Semax: The Neurotrophic Probe
Semax derives from the ACTH(4-10) fragment of adrenocorticotropic hormone, stripped of hormonal activity and stabilized for research use. The literature clusters around brain-derived neurotrophic factor: studies examine BDNF expression changes, melanocortin receptor signaling in the CNS, and neuroprotective endpoints in preclinical injury and cognition models. When a study design needs a neurotrophic or attention-related probe, Semax is typically the choice.
Selank: The Anxiolytic-Focused Analog
Selank is built instead from tuftsin, a naturally occurring immunomodulatory peptide. Its research profile centers on anxiety-related behavioral models, GABAergic and monoamine neurotransmission, and the crosstalk between immune signaling and the nervous system โ a distinctive niche where immunology meets behavioral neuroscience.
Structural Cousins, Different Questions
The shared Pro-Gly-Pro extension gives both peptides their stability, but the parent molecules define the research: an ACTH fragment points Semax toward neurotrophic signaling, while a tuftsin backbone points Selank toward neuroimmune and anxiolytic-related pathways. They are complements rather than substitutes.
Studying Them Together
Because the profiles are complementary, some laboratories run both compounds within a program — our Selank / Semax combination supplies the pair in a single research preparation, while individual vials support single-compound designs. Related cognition-focused compounds like Dihexa round out the Cognitive Enhancement collection.
Material Quality in Neuropeptide Research
CNS-focused studies are especially sensitive to impurities. Every Pristine Aminos neuropeptide batch is independently tested at 99%+ purity and ships with a Certificate of Analysis.
All products discussed are intended strictly for in-vitro research and laboratory use only. They are not for human or veterinary use, consumption, or therapeutic application.



