Thymosin Alpha-1
Thymosin Alpha-1 sits apart from the rest of KYIN's Healing & Recovery category — it isn't a tissue-repair peptide, but a thymic peptide studied for immune-system modulation, with one of the more extensive approval and trial histories of any compound referenced on this site.
Not currently stocked by KYIN Peptides, but available to order — see availability below.
What Is Thymosin Alpha-1?
Despite sharing a thymic naming lineage with TB-500's parent molecule (thymosin beta-4), Thymosin Alpha-1 is a distinct compound. Rather than wound closure or collagen synthesis, its research base centers on immune-system modulation — specifically TLR3/4/9 receptor binding and downstream NF-κB/IRF3 signaling, which promotes the maturation and activation of dendritic cells, macrophages, and T-cells.
Research Focus
Thymosin Alpha-1's research profile centers on immune function and general health rather than localized tissue repair, distinguishing it from the gastric-, actin-, and copper-based repair pathways studied for compounds like BPC-157, TB-500, and GHK-Cu. See our Healing & Recovery research overview for how it fits alongside KYIN's stocked recovery-focused peptides, or how it compares to Vilon, another immune-modulation compound referenced on this site.
Clinical & Preclinical Trial Data
This is one of the few compounds referenced on this site with a genuinely large, modern randomized trial behind it — and that trial reported a negative result. The ETASS trial (2013, Critical Care; 361 ICU patients with severe sepsis across six Chinese hospitals, 181 on Tα1 versus 180 controls) found a trend toward improved 28-day survival that did not reach statistical significance (p=0.06). The much larger follow-up TESTS trial (2025, The BMJ; 1,106 sepsis patients across 22 Chinese centers, double-blind, placebo-controlled Phase 3) found no significant difference in 28-day mortality (23.4% with Tα1 versus 24.1% with placebo; hazard ratio 0.97, p=0.82).
Separately from the sepsis research, synthetic Thymosin Alpha-1 (thymalfasin, brand name Zadaxin) is an approved prescription medicine in more than 35 countries for chronic hepatitis B and C, and holds FDA orphan drug designation for several indications in the United States, though it has not received full FDA approval for any indication.
Availability
Thymosin Alpha-1 is not part of KYIN Peptides' standard catalogue, but it is available to order — contact us directly and we'll source it for you.
Thymosin Alpha-1 questions
What is Thymosin Alpha-1?
Thymosin Alpha-1 is a thymic peptide studied for immune-system modulation. Despite sharing a thymic naming lineage with TB-500's parent molecule (thymosin beta-4), it is a distinct compound studied for immune function rather than wound closure or collagen synthesis, working through TLR3/4/9 receptor binding and downstream NF-κB/IRF3 signaling that promotes the maturation and activation of dendritic cells, macrophages, and T-cells.
Is Thymosin Alpha-1 an approved drug?
As thymalfasin (brand name Zadaxin), synthetic Thymosin Alpha-1 is an approved prescription medicine in more than 35 countries for chronic hepatitis B and C, and holds FDA orphan drug designation for several indications in the United States — though it has not received full FDA approval for any indication.
Does Thymosin Alpha-1 work for sepsis?
The evidence doesn't support that. The ETASS trial (2013, 361 ICU sepsis patients) found a trend toward improved survival that did not reach statistical significance. The much larger follow-up TESTS trial (2025, 1,106 sepsis patients) found no significant difference in 28-day mortality versus placebo.
Does KYIN Peptides sell Thymosin Alpha-1?
Not as part of our standard catalogue, but yes — it's available to order. Contact us directly and we'll source it for you.
Interested in sourcing Thymosin Alpha-1?
Contact us and we'll help you source it, or browse our stocked recovery-focused peptides.