Data edition of
Residue An evidence-graded reference for peptide science

A peptide class of 5 compounds

Regulatory peptides

How strong is the evidence for selank, semax, epitalon, DSIP and kisspeptin-10?

Three small clear glass ampoules in a row beside an unlabeled dropper bottle, folded blank paper and an oxblood ribbon

Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro), semax (ACTH(4-7) extended with Pro-Gly-Pro) and epitalon (Ala-Glu-Asp-Gly) have something in common: they are short synthetic peptides, and the human studies we found for them were published mainly in Russian journals1PubMed[Efficacy and possible mechanisms of action of a new peptide anxiolytic selank in the therapy of generalized anxiety disorders and neurasthenia]. Zozulia AA et al. Zh Nevrol Psikhiatr Im S S Korsakova. 2008.,2PubMed[The efficacy of semax in the tretament of patients at different stages of ischemic stroke]. Gusev EI et al. Zh Nevrol Psikhiatr Im S S Korsakova. 2018.,3PubMedPineal-regulating tetrapeptide epitalon improves eye retina condition in retinitis pigmentosa. Khavinson V et al. Neuro Endocrinol Lett. 2002.. DSIP, a nonapeptide isolated from rabbit blood in 1977, was tested in small insomnia studies in the 1980s; the best-controlled one found weak effects4PubMedDelta sleep-inducing peptide (DSIP): a still unresolved riddle. Kovalzon VM & Strekalova TV J Neurochem. 2006.,5PubMedEffects of delta sleep-inducing peptide on sleep of chronic insomniac patients. A double-blind study. Bes F et al. Neuropsychobiology. 1992.. Kisspeptin-10 is different again: a fragment of a hypothalamic hormone, studied in human physiology experiments that measure LH and testosterone responses6PubMedKisspeptin-10 is a potent stimulator of LH and increases pulse frequency in men. George JT et al. J Clin Endocrinol Metab. 2011..

None has an FDA-approved application. FDA places kisspeptin-10 in compounding Category 2, and lists selank acetate, semax, epitalon and emideltide (DSIP) among compounding nominations that were withdrawn, with the agency's safety concerns still recorded7FDACertain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks. U.S. FDA, content current as of 04/22/2026.. ClinicalTrials.gov returned no registered study for semax, epitalon or DSIP at our last fetch8TrialClinicalTrials.gov registry search: semax. 0 registered studies at fetch.,9TrialClinicalTrials.gov registry search: epitalon OR epithalon. 0 registered studies at fetch.,10TrialClinicalTrials.gov registry search: "delta sleep-inducing peptide" OR DSIP OR emideltide. 0 registered studies at fetch..

Table 1. Regulatory peptides on Residue, by best evidence grade. Bars show PubMed records on a log scale; counts are from the data edition.
GradeCompoundClassLiteratureRegistered studies
B Kisspeptin-10Not FDA-approved · FDA compounding Category 2 (503A) Neuro & bioregulators 317 36 · 5 active
C DSIPNot FDA-approved · FDA compounding nomination withdrawn Neuro & bioregulators 463 0
C SemaxNot FDA-approved · FDA compounding nomination withdrawn Neuro & bioregulators 209 0
C EpitalonNot FDA-approved · FDA compounding nomination withdrawn Neuro & bioregulators 121 0
C SelankNot FDA-approved · FDA compounding nomination withdrawn Neuro & bioregulators 68 2

Monographs in this class

  • B
    Kisspeptin-10

    The shortest fully active form of kisspeptin, a hypothalamic hormone that switches on the reproductive axis. Human studies are small physiology experiments measuring hormone responses.

  • C
    DSIP

    A nine-residue peptide isolated from rabbit blood in 1977 and named for slow-wave sleep. Small human studies in the 1980s were positive; the best-controlled one was not.

  • C
    Semax

    A synthetic analog of an ACTH fragment, used in Russia for stroke. Its human evidence comes from small, mostly non-randomized Russian clinical studies.

  • C
    Epitalon

    The tetrapeptide Ala-Glu-Asp-Gly, modeled on a bovine pineal extract and promoted as an anti-aging peptide. Its best evidence is in cell lines and mice.

  • C
    Selank

    A synthetic seven-residue peptide studied in Russia as an anxiolytic. The human evidence is a handful of small Russian clinical reports.

Comparisons

References

Every source below was retrieved from its official API or page and cached on the data-edition date. Numbers match the margin notes.

  1. 1 PubMed Zozulia AA, Neznamov GG, Siuniakov TS, 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.
  2. 2 PubMed Gusev EI, Martynov MY, Kostenko EV, 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; doi:10.17116/jnevro20181183261-68.
  3. 3 PubMed Khavinson V, Razumovsky M, Trofimova S, et al. Pineal-regulating tetrapeptide epitalon improves eye retina condition in retinitis pigmentosa. Neuro Endocrinol Lett 2002. PMID 12195242.
  4. 4 PubMed Kovalzon VM, Strekalova TV. Delta sleep-inducing peptide (DSIP): a still unresolved riddle. J Neurochem 2006. PMID 16539679; doi:10.1111/j.1471-4159.2006.03693.x.
  5. 5 PubMed Bes F, Hofman W, Schuur J, et al. Effects of delta sleep-inducing peptide on sleep of chronic insomniac patients. A double-blind study. Neuropsychobiology 1992. PMID 1299794; doi:10.1159/000118919.
  6. 6 PubMed George JT, Veldhuis JD, Roseweir AK, et al. Kisspeptin-10 is a potent stimulator of LH and increases pulse frequency in men. J Clin Endocrinol Metab 2011. PMID 21632807; doi:10.1210/jc.2011-0089.
  7. 7 FDA Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks. U.S. FDA, content current as of 04/22/2026.
  8. 8 ClinicalTrials.gov ClinicalTrials.gov registry search: semax. 0 registered studies at fetch.
  9. 9 ClinicalTrials.gov ClinicalTrials.gov registry search: epitalon OR epithalon. 0 registered studies at fetch.
  10. 10 ClinicalTrials.gov ClinicalTrials.gov registry search: "delta sleep-inducing peptide" OR DSIP OR emideltide. 0 registered studies at fetch.