Semax and Selank are often mentioned together within neuropeptide research. On the surface they resemble each other — both are short peptides in the cognition & focus category — but their origin and the research around them differ substantially. In this guide we place them side by side, informatively and strictly research-only.
Semax is derived from an ACTH fragment and is mainly studied in cognition and focus research. Selank is derived from the immune peptide tuftsin and appears more often in anxiety and stress research. Different origin, different research questions. For research use only.
Semax vs Selank: the difference at a glance
The core difference lies in the origin: Semax stems from a hormone fragment, Selank from an immune peptide. The table below sets the key characteristics side by side. New to peptides? First read what peptides are.
What is Semax?
Semax is a synthetic peptide derived from a fragment of the ACTH hormone that, in preclinical research, is mainly associated with cognition and attention. The full background, mechanism and research status can be found in what is Semax.
What is Selank?
Selank is a synthetic analogue of the body’s own immune peptide tuftsin and, in a research context, is more often studied in relation to the stress and anxiety response. More about the background can be found in what is Selank.
Which suits which research?
The choice between Semax and Selank follows from the research question, not from a ranking of ‘strength’. If a study revolves around attention, memory or neuroprotection, Semax aligns more closely with that. If it concerns the stress or anxiety response, Selank is the more logical research subject. Browse the full cognition & focus category.
This comparison is for information only. Semax and Selank at Peptide Lab are intended for laboratory and research purposes — not a medicine, not for human or animal consumption and not medical advice. No efficacy or health claims are made.
For research: purity and documentation
If you work with Semax or Selank, always check the purity and the batch number. Read how to read a COA and view the public certificate per lot number. Both peptides are supplied as a lyophilised powder — calculate the reconstitution ratio with the reconstitution calculator.
Frequently asked questions about Semax and Selank
What is the difference between Semax and Selank?
Both are short research peptides studied in neuroscience, but with a different origin. Semax is derived from a fragment of the ACTH hormone and is mainly researched in relation to cognition and focus. Selank is derived from the immune peptide tuftsin and is more often examined in anxiety and stress research.
Can you combine Semax and Selank in research?
In some research designs both peptides are studied side by side because they act on different mechanisms. Peptide Lab makes no claims about combined use; every experiment requires its own controlled design.
Which is better, Semax or Selank?
'Better' is not a meaningful statement outside a specific research question. The two peptides are studied for different purposes. The choice depends entirely on the mechanism a researcher wants to investigate.
Are Semax and Selank pure at Peptide Lab?
Yes. Semax is lab-verified at 99.4% purity and Selank at 99.1%, with a public certificate per batch. Both for research purposes only.
