Side-by-side comparison of mechanisms, dosing, interactions, and stacking potential.
| Selank | Semax | |
|---|---|---|
| Category | Peptides | Peptides |
| Standard Dose | Research indicates 250-500 mcg daily via intranasal administration (0.15% solution, 2-3 drops per nostril). | Research indicates 200-600 mcg daily via intranasal administration (0.1% solution, 2-3 drops per nostril). |
| Timing | Can be dosed morning through evening. Unlike Semax, Selank is calming and can be used at night. | Morning and early afternoon dosing (avoid evening — may cause stimulation/insomnia). Intranasal preferred for rapid CNS delivery. |
| Cycle Duration | 14-21 day cycles with equal rest periods. | 10-14 day cycles with equal rest periods. Some protocols use 3-5 day on / 2 day off patterns. |
| Evidence Level | moderate_human | moderate_human |
Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro) is a synthetic heptapeptide analog of the immunomodulatory peptide tuftsin (from IgG heavy chain) with a Pro-Gly-Pro extension for metabolic stability. It allosterically modulates GABA-A receptors, enhancing GABA binding and GABAergic neurotransmission. Selank modifies mRNA levels of 84 genes involved in GABAergic neurotransmission in the frontal cortex, enhances enkephalinase inhibition (increasing endogenous enkephalin levels), and modulates serotonergic and noradrenergic systems to produce anxiolytic and nootropic effects.
Research indicates 250-500 mcg daily via intranasal administration (0.15% solution, 2-3 drops per nostril).
Can be dosed morning through evening. Unlike Semax, Selank is calming and can be used at night.
14-21 day cycles with equal rest periods.
Semax (Met-Glu-His-Phe-Pro-Gly-Pro) is a synthetic heptapeptide analog of the ACTH(4-10) fragment that rapidly upregulates brain-derived neurotrophic factor (BDNF) and its signaling receptor TrkB in the hippocampus (1.4-fold BDNF protein increase, 3-fold exon III BDNF mRNA increase). It activates dopaminergic and serotonergic brain systems, enhances neurotrophin gene expression (BDNF, NGF), and modulates intracellular calcium dynamics in brain neurons. Semax lacks ACTH's corticotropic activity, acting purely as a nootropic/neuroprotective agent.
Research indicates 200-600 mcg daily via intranasal administration (0.1% solution, 2-3 drops per nostril).
Morning and early afternoon dosing (avoid evening — may cause stimulation/insomnia). Intranasal preferred for rapid CNS delivery.
10-14 day cycles with equal rest periods. Some protocols use 3-5 day on / 2 day off patterns.
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