Semax Nasal Spray vs Selank Nasal Spray: Which Fits Which Research Question?
Semax nasal spray fits research questions about attention, memory, learning and BDNF signalling, while Selank nasal spray fits research questions about anxiety, the stress response and GABA signalling. Both are seven-amino-acid synthetic peptides from Russian peptide research, both end in the same Pro-Gly-Pro tail, and in a 2020 brain-imaging study of 52 healthy participants each showed both shared and specific effects on amygdala connectivity (Panikratova, Dokl Biol Sci, 2020). Vistara Labs supplies each as a ready-mixed spray at 350 mcg per spray, and the combined Selank + Semax Nasal Spray holds both in one bottle.
Findings
- Semax is an analogue of the 4 to 10 fragment of ACTH (Met-Glu-His-Phe-Pro-Gly-Pro); in an animal model, intranasal Semax raised BDNF protein in the basal forebrain within 3 hours (Dolotov, J Neurochem, 2006).
- In 110 patients after ischaemic stroke, Semax raised plasma BDNF and improved final Barthel Index scores (Gusev, Zh Nevrol Psikhiatr, 2018).
- In 62 patients with generalised anxiety disorder and neurasthenia, Selank matched the anxiolytic effect of medazepam and added antiasthenic and psychostimulant effects (Zozulia, Zh Nevrol Psikhiatr, 2008).
- In 60 patients with anxiety disorders, Selank showed pronounced anxiolytic and mild nootropic effects that lasted a week after the last administration (Medvedev, Zh Nevrol Psikhiatr, 2014).
What is the difference between Semax and Selank?
The difference is the parent molecule and the research focus. Semax is built from a fragment of ACTH, a pituitary hormone, and is studied as a nootropic. Selank is an analogue of tuftsin, a short immune peptide, and is studied as an anxiolytic. Both carry a Pro-Gly-Pro tail that makes them more resistant to enzymes. Our full comparison is Semax vs Selank: What Actually Separates Them.
| Semax Nasal Spray | Selank Nasal Spray | |
|---|---|---|
| Parent molecule | ACTH (4 to 10) fragment | Tuftsin |
| Main research focus | Attention, memory, learning, BDNF | Anxiety, stress response, GABA signalling |
| Key human study | 110 stroke patients, BDNF and recovery (2018) | 62 patients with anxiety and neurasthenia (2008) |
| Sizes | 10 mg in 5 mL or 20 mg in 10 mL | 10 mg in 5 mL or 20 mg in 10 mL |
| Sprays per bottle | About 28 or about 57 | About 28 or about 57 |
| Amount per spray | 350 mcg | 350 mcg |
What is Semax nasal spray best suited to?
Semax is best suited to research on cognition, neuroprotection and neurotrophic signalling. Its most consistent research thread is brain-derived neurotrophic factor (BDNF), a protein central to how the brain forms and reshapes connections.
- BDNF in the brain. In an animal model, the basal forebrain contained specific Semax binding sites, and intranasal Semax raised BDNF protein there within 3 hours, but not in the cerebellum (Dolotov, 2006).
- Stroke recovery. In 110 patients after ischaemic stroke, Semax raised plasma BDNF, which stayed high for the whole study, and Semax with higher BDNF sped functional improvement and improved final Barthel Index scores (Gusev, 2018).
- Brain networks. In 24 healthy volunteers, intranasal Semax produced a larger frontal (medial frontal cortex) component of the default mode network than placebo on resting-state fMRI (Lebedeva, Bull Exp Biol Med, 2018).
More: Semax Benefits: What the Research Shows and Semax and Stroke Recovery.
What is Selank nasal spray best suited to?
Selank is best suited to research on anxiety, the stress response and emotional regulation, studied for a calmer state without sedation.
- Generalised anxiety and neurasthenia. In 62 patients, Selank (30 patients) and medazepam (32 patients) produced similar anxiolytic effects, and Selank also had antiasthenic and psychostimulant effects (Zozulia, 2008).
- Anxiety disorders. In 60 patients with phobic-anxiety and somatoform disorders compared against phenazepam, Selank showed pronounced anxiolytic and mild nootropic effects, a positive effect on quality of life, and an anxiolytic effect that lasted a week after the last administration (Medvedev, 2014).
- GABA signalling. In an animal model, Selank changed the expression of 45 genes involved in neurotransmission within 1 hour, in a pattern that correlated with GABA itself, pointing to allosteric modulation of the GABA system (Volkova, Front Pharmacol, 2016).
More: Selank and Anxiety: The Research and Selank Benefits: What the Research Shows.
Have Semax and Selank been studied side by side?
Yes. A 2020 resting-state fMRI study in 52 healthy participants compared Semax, Selank and placebo, with scans before and 5 and 20 minutes after. It examined the amygdala, a key region for anxiety, and the dorsolateral prefrontal cortex, a key region for working memory. The authors defined both general and specific effects of Selank and Semax on connectivity between the right amygdala and the right temporal cortex, the first time this had been shown (Panikratova, Dokl Biol Sci, 2020).
What is in the Selank + Semax nasal spray?
The Selank + Semax Nasal Spray holds 10 mg of Selank and 10 mg of Semax in 10 mL of sterile saline. It delivers about 57 sprays, each carrying about 175 mcg of Selank and about 175 mcg of Semax. It suits research designs that study the calming and the activating peptide together in one model. See Buy Selank + Semax Nasal Spray in Canada.
Which spray fits which research question?
| Research question | Spray |
|---|---|
| Attention, memory, learning, BDNF | Semax Nasal Spray |
| Anxiety, stress response, GABA signalling | Selank Nasal Spray |
| Both pathways in one model | Selank + Semax Nasal Spray |
| Both peptides plus cellular energy | Cognitive Clarity Spray Stack (Semax, Selank and NAD+ sprays) |
| Calm plus sleep regulation | Sleep & Calm Spray Stack (DSIP and Selank sprays) |
For the route question, Semax and Selank: intranasal vs subcutaneous research routes covers how the two formats compare.
What about N-acetyl Semax amidate and N-acetyl Selank amidate?
Vistara Labs does not currently stock N-acetyl Semax amidate, but you can request it: contact us and we will source it for you. The closest product we sell is the Semax Nasal Spray.
Vistara Labs does not currently stock N-acetyl Selank amidate, but you can request it: contact us and we will source it for you. The closest product we sell is the Selank Nasal Spray.
Where to buy Semax and Selank nasal sprays in Canada
- Three sprays, one pump. Semax, Selank and Selank + Semax all use the same metered pump, 0.175 mL per press, and arrive ready-mixed with nothing to reconstitute.
- Same-day dispatch. Orders placed before 3 pm Pacific, Monday to Friday, leave the same business day by tracked Canada Post Xpresspost from within Canada.
- Keep it cold. Like any peptide in solution, the spray is kept refrigerated once it arrives; see How to Store a Peptide Nasal Spray.
- Prefer powder? The lyophilised Semax 10 mg vial and Selank 10 mg vial are also available.
- Buying guides. Buy Semax Nasal Spray in Canada and Buy Selank Nasal Spray in Canada.
Semax and Selank are supplied for laboratory research use only. The human studies above were clinical research using pharmaceutical preparations under medical supervision.
Frequently asked questions
What is the main difference between Semax and Selank?
Semax is an ACTH-fragment analogue studied for attention, memory and BDNF signalling. Selank is a tuftsin analogue studied for anxiety, the stress response and GABA signalling.
How much peptide is in each Semax or Selank spray?
350 mcg per spray for both. The 10 mg bottle holds 10 mg in 5 mL, about 28 sprays, and the 20 mg bottle holds 20 mg in 10 mL, about 57 sprays.
What is in the Selank + Semax nasal spray?
10 mg of Selank and 10 mg of Semax in 10 mL, about 57 sprays, with about 175 mcg of each peptide per spray.
Have Semax and Selank been compared in humans?
Yes. A 2020 resting-state fMRI study of 52 healthy participants compared Semax, Selank and placebo and found general and specific effects of each on connectivity between the right amygdala and the right temporal cortex.
Does Vistara Labs sell N-acetyl Semax amidate or N-acetyl Selank amidate?
Vistara Labs does not currently stock N-acetyl Semax amidate, but you can request it: contact us and we will source it for you. Vistara Labs does not currently stock N-acetyl Selank amidate, but you can request it: contact us and we will source it for you.
Where can I buy Semax and Selank nasal sprays in Canada?
Vistara Labs supplies the Semax Nasal Spray, the Selank Nasal Spray and the Selank + Semax Nasal Spray, ready-mixed and shipped from within Canada by Canada Post Xpresspost.
Product details from vistaralabs.ca, October 2026. Sources: Dolotov OV et al. Semax, an analogue of adrenocorticotropin (4-10), binds specifically and increases levels of brain-derived neurotrophic factor protein in rat basal forebrain. J Neurochem. 2006. PMID 16635254. Gusev EI et al. The efficacy of semax in the tretament of patients at different stages of ischemic stroke. Zh Nevrol Psikhiatr Im S S Korsakova. 2018. PMID 29798983. Lebedeva IS et al. Effects of Semax on the Default Mode Network of the Brain. Bull Exp Biol Med. 2018. PMID 30225715. Zozulia AA et al. Efficacy and possible mechanisms of action of a new peptide anxiolytic selank in the therapy of generalized anxiety disorders and neurasthenia. Zh Nevrol Psikhiatr Im S S Korsakova. 2008. PMID 18454096. Medvedev VE et al. A comparison of the anxiolytic effect and tolerability of selank and phenazepam in the treatment of anxiety disorders. Zh Nevrol Psikhiatr Im S S Korsakova. 2014. PMID 25176261. Volkova A et al. Selank Administration Affects the Expression of Some Genes Involved in GABAergic Neurotransmission. Front Pharmacol. 2016. PMID 26924987. Panikratova YR et al. Functional Connectomic Approach to Studying Selank and Semax Effects. Dokl Biol Sci. 2020. PMID 32342318. Selank as a tuftsin analogue: Kolik LG et al. Bull Exp Biol Med. 2019. PMID 31625062.
More on this: Buy Peptide Nasal Sprays in Canada and Peptides for Focus and Anxiety: What the Research Shows.
All products supplied by Vistara Labs are intended for laboratory research use only. They are not drugs, are not approved for human or veterinary use, and are not intended to diagnose, treat, cure or prevent any condition. Nothing on this page constitutes medical advice or guidance for use in humans.
