Semax vs Selank
Semax and Selank are both synthetic seven-amino-acid peptides with the same Pro-Gly-Pro tail, but they are built on different parent peptides. Semax is an ACTH(4-10) analogue studied mainly in Russian stroke and cerebrovascular patients, while Selank is a tuftsin analogue studied mainly in small Russian anxiety trials. Both are sold here as a 10 mg vial and as a ready-made nasal spray.
Side by side
| Semax | Selank | |
|---|---|---|
| Class | Synthetic ACTH(4-10) analogue (heptapeptide): Met-Glu-His-Phe-Pro-Gly-Pro | Synthetic tuftsin analogue (heptapeptide): Thr-Lys-Pro-Arg-Pro-Gly-Pro |
| Mechanism studied | BDNF and NGF gene expression in rat brain, gene expression after experimental cerebral ischaemia, copper and zinc binding, enkephalinase inhibition in human serum | Inhibition of enkephalin-degrading enzymes in blood, cytokine balance, BDNF in rat brain and GABA-related gene expression in cultured cells |
| What's studied | Ischaemic stroke recovery, cerebrovascular insufficiency, peptic ulcer, resting-state brain imaging in healthy volunteers | Generalised anxiety disorder, neurasthenia, phobic-anxiety disorders, morphine withdrawal and ethanol models in rats |
| Strength of the evidence | Five small Russian clinical studies in people (none a large blinded randomised trial), plus rat, mouse and cell work | Five small Russian clinical studies in people, some randomised against benzodiazepines, plus mouse and rat work; doses not stated in the human abstracts |
| Forms sold here | Lyophilised powder vial; ready-made nasal spray | Lyophilised powder vial; ready-made nasal spray |
| Sizes sold here | 10 mg vial; 10 mg / 10 mL nasal spray (1 mg per mL) | 10 mg vial; 15 mg / 10 mL nasal spray (1.5 mg per mL) |
| Storage | Vial: −20 °C, dry and dark; 2–8 °C once mixed. Spray: 2–8 °C, capped, away from light | Vial: −20 °C, dry and dark; 2–8 °C once mixed. Spray: 2–8 °C, capped, away from light |
| Cited studies on our pages | 8 | 8 |
Key differences
Parent peptide: Semax is built from the ACTH(4-7) fragment of adrenocorticotropic hormone, while Selank is built from tuftsin, a four-amino-acid immune peptide. The shared Pro-Gly-Pro tail is added to both to slow their breakdown.
Research focus: the Semax literature centres on stroke, cerebral ischaemia and neurotrophic factors such as BDNF and NGF, while the Selank literature centres on anxiety disorders and on how it lengthens the half-life of leu-enkephalin.
Spray strength: the Semax spray holds 10 mg in 10 mL and the Selank spray holds 15 mg in 10 mL, so the two are not interchangeable by volume. The vials are both 10 mg.
FAQ
What is the difference between Semax and Selank?
Semax is a synthetic analogue of ACTH(4-10), and Selank is a synthetic analogue of tuftsin. Both are heptapeptides ending in Pro-Gly-Pro. Semax has mostly been studied in Russian stroke and cerebrovascular patients, and Selank in small Russian anxiety trials.
Has any study tested Semax and Selank together?
Not as a combination. One placebo-controlled fMRI study in healthy participants (n=52) gave either Selank or Semax and compared each with placebo. No study in our records gave both peptides to the same subjects.
Is Semax or Selank better studied?
Neither has a large, blinded, randomised trial in our records. Each has eight cited studies on its page: five small Russian clinical studies and three animal or cell studies. Selank's human abstracts do not state the dose, route or treatment length, and neither compound has long-term human safety data here.
Are Semax and Selank legal in Australia?
Neither is registered on the ARTG, and there is no TGA-approved product containing either one. Tasman supplies both as research chemicals for laboratory research only, not for human or veterinary use.