Side-by-side comparison of mechanisms, dosing, interactions, and stacking potential.
| Selank | Thymosin Alpha-1 | |
|---|---|---|
| Category | Peptides | Growth Factors |
| Standard Dose | Research indicates 250-500 mcg daily via intranasal administration (0.15% solution, 2-3 drops per nostril). | Research indicates 1.6 mg administered twice weekly via subcutaneous injection. |
| Timing | Can be dosed morning through evening. Unlike Semax, Selank is calming and can be used at night. | Morning administration preferred. No food timing restrictions. |
| Cycle Duration | 14-21 day cycles with equal rest periods. | 8-12 week cycles, with periodic breaks. Some protocols use continuous low-dose maintenance. |
| Evidence Level | moderate_human | strong_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.
Thymosin Alpha-1 is a 28-amino acid peptide naturally produced by the thymus that acts as a pleiotropic immune modulator through Toll-like receptors (TLR2, TLR3, TLR4, TLR7, TLR9) on myeloid and plasmacytoid dendritic cells. It activates downstream IRF3, NF-kB, p38MAPK, and MyD88 signaling pathways to promote cytokine production. It modulates TNF-alpha, IFN-gamma, and IL-2 in CD4+ and CD8+ T lymphocytes by upregulating CD40/CD40L and downregulating PD-L1/PD-1 expression, enhancing both innate and adaptive immunity.
Research indicates 1.6 mg administered twice weekly via subcutaneous injection.
Morning administration preferred. No food timing restrictions.
8-12 week cycles, with periodic breaks. Some protocols use continuous low-dose maintenance.
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