Are Semax and Selank the same peptide?

No. They are distinct synthetic heptapeptides with different sequences (MEHFPGP vs TKPRPGP), different origins (ACTH-fragment-related vs tuftsin-related) and different research profiles.

Can findings for Semax be applied to Selank?

No. Research findings for one peptide should not be transferred to the other. Each has its own evidence base.

Are PepDirect Semax and Selank intended for human use?

No. Both are supplied strictly as laboratory research materials. They are not marketed as medicines, food supplements or products for human or veterinary use.

↳ Research overview

Semax vs Selank

Semax and Selank are distinct synthetic peptides with different sequences, development histories and research literatures. Although they are frequently discussed together, evidence involving one should not be transferred to the other.

Both are heptapeptides that end in a Pro-Gly-Pro (PGP) motif. That shared motif does not make them chemically or pharmacologically interchangeable.

For laboratory research context only. PepDirect supplies both compounds as research materials, not for human or veterinary use.

§ Semax

What is Semax?

Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro (MEHFPGP). It is based on the ACTH(4-7) fragment with a C-terminal Pro-Gly-Pro extension intended to increase enzymatic stability, and has been studied in neurobiology research including BDNF/NGF signalling, gene-expression research and experimental neurotransmitter-pathway models.

§ Selank

What is Selank?

Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro (TKPRPGP). Its N-terminal region corresponds to the tuftsin tetrapeptide (Thr-Lys-Pro-Arg) with a C-terminal Pro-Gly-Pro extension. It has been investigated in neurochemical, gene-expression and behavioural research models.

§ Comparison

Side-by-side comparison

Peptide length, 7 amino acids (Semax) vs 7 amino acids (Selank).
Sequence, MEHFPGP (Semax) vs TKPRPGP (Selank).
Research origin, ACTH(4-7)-fragment-related (Semax) vs tuftsin-related (Selank).
Shared terminal motif, PGP (both).
Chemical identity, distinct compounds with different CAS numbers, molecular formulas and molecular weights.
Research literature, separate evidence bases; findings for one should not be transferred to the other.

§ Rationale

Why are Semax and Selank compared?

Semax and Selank are both synthetic heptapeptides originating from Russian neuroscience research, and both carry the terminal PGP motif intended to improve stability. That shared background is why the two names frequently appear together in review articles, but their sequences, receptor/pathway research profiles and mechanisms are not the same.

§ Research themes

Research themes for each peptide

Semax, neurotrophic factor / BDNF-NGF-related research, gene-expression research, neurotransmitter-pathway studies, experimental neuroprotection models.
Selank, neurochemical signalling research, experimental GABA-system research, gene-expression studies, stress-response behavioural models (largely animal / preclinical).

The research themes above are areas explored in cellular and animal models. They are not statements of demonstrated benefits for anxiety, mood, focus or clinical use in any disease-state context.

§ Mechanism

Do they have the same research mechanism?

No. There may be overlapping research themes, both are studied in neurobiological contexts, but their structures and research literatures are different, and one mechanism should not automatically be assigned to the other.

§ Research product

View the research products

Semax and Selank are supplied as separate research materials with lot-specific documentation.

View Semax Research Peptide →

§ References

Selected research references

Semax · PubChem CID 9811102 (heptapeptide MEHFPGP)PubChem (NCBI)
Selank · PubChem CID 11765600 (heptapeptide TKPRPGP)PubChem (NCBI)
Semax and Selank, comparative research on Russian regulatory peptidesPubMed · Medvedev et al.
Regulatory peptide Selank, behavioural studies in animal modelsPubMed · Kozlovskii et al.

§ FAQ

Frequently asked questions

Are Semax and Selank the same peptide?: No. They are distinct synthetic heptapeptides with different sequences (MEHFPGP vs TKPRPGP), different origins (ACTH-fragment-related vs tuftsin-related) and different research profiles.
What is the sequence of Semax?: Met-Glu-His-Phe-Pro-Gly-Pro (MEHFPGP).
What is the sequence of Selank?: Thr-Lys-Pro-Arg-Pro-Gly-Pro (TKPRPGP).
Why are Semax and Selank compared?: Both are synthetic heptapeptides from Russian neuroscience research and both end in a Pro-Gly-Pro (PGP) motif. That shared background is why they appear together in review literature, not because they are interchangeable.
Do Semax and Selank have the same research mechanism?: No. Their structures and published research literatures are different, and one mechanism should not automatically be assigned to the other.
Can findings for Semax be applied to Selank?: No. Research findings for one peptide should not be transferred to the other. Each has its own evidence base.
Are PepDirect Semax and Selank intended for human use?: No. Both are supplied strictly as laboratory research materials. They are not marketed as medicines, food supplements or products for human or veterinary use.

§ Related