What it is
Thymosin alpha-1 is an immune-modulating peptide studied for enhancing T-cell function and natural killer (NK) cell activity, two components of the immune system. It holds FDA orphan drug status for hepatitis B, a designation intended to support development of treatments for rare or under-served conditions, and it is used in integrative medicine settings for general immune support.
In the PeptidesAI encyclopedia it is categorized under immune and longevity, alongside compounds such as NAD+ and MOTS-c, though its regulatory history through orphan drug status is unusual among that group. Because thymosin alpha-1 is studied across several different arms of the immune system rather than a single pathway, it appears in contexts ranging from chronic viral infection to general immune support in integrative settings.
How it's thought to work
Thymosin alpha-1 is studied for enhancing the maturation and differentiation of T-cells, increasing NK cell activity, modulating cytokine production (the signaling proteins immune cells use to communicate), and supporting dendritic cell function, all of which contribute to immune surveillance, the body's ongoing monitoring for infection or abnormal cells. Supporting several of these processes together is presented as the reason thymosin alpha-1 is described as a broad immune modulator rather than a compound with one narrow target.
What the research says
Thymosin alpha-1 is approved in some countries for hepatitis B and C, and it holds FDA orphan drug status in the United States. There is an extensive body of clinical data supporting its immune-modulating effects.
Reported side effects
Thymosin alpha-1 is generally described as very well-tolerated. Rare injection site reactions have been reported. No serious safety signals are described in the available material.
Reconstitution
Thymosin alpha-1 is supplied as a lyophilized (freeze-dried) powder and is typically reconstituted with bacteriostatic (BAC) water before use. It commonly comes in 1.6 mg and 3.2 mg vials. The amount of peptide in the vial is fixed; the water added only changes how concentrated the solution is.
Worked example. A 3.2 mg vial is 3,200 mcg. Reconstituted with 1 mL of BAC water, that works out to 3,200 mcg ÷ 1 mL = 3,200 mcg/mL. On a U-100 insulin syringe, where each unit is 0.01 mL, each unit holds 3,200 × 0.01 = 32 mcg. A 1.6 mg vial with 1 mL comes out at 1,600 mcg/mL instead, or 16 mcg per unit. Use the peptide reconstitution calculator to work out the concentration and units for any vial size and water volume.
Important notes
Thymosin alpha-1 holds FDA orphan drug status specifically for hepatitis B, a designation that supports research and development rather than constituting general approval, and it is approved for use in some other countries.
Frequently asked questions
These questions cover the same ground as the sections above, in a shorter format.
What is Thymosin alpha-1?
An immune-modulating peptide studied for enhancing T-cell and NK cell activity, holding FDA orphan drug status for hepatitis B.
How is Thymosin alpha-1 thought to work?
It is studied for enhancing T-cell maturation, increasing NK cell activity, modulating cytokine production, and supporting dendritic cell function.
What does the research on Thymosin alpha-1 say?
It is approved in some countries for hepatitis B and C and holds FDA orphan drug status, with extensive clinical data supporting immune-modulating effects.
What are the reported side effects of Thymosin alpha-1?
Generally very well-tolerated, with rare injection site reactions reported.
How much is one unit from a 3.2 mg Thymosin alpha-1 vial?
With 1 mL of BAC water, a 3.2 mg vial is 3,200 mcg/mL, so one unit on a U-100 syringe (0.01 mL) holds 32 mcg.
The full entry, plus the calculator
The PeptidesAI app has the complete encyclopedia entry for Thymosin alpha-1 — one of 70 compounds covered — plus the reconstitution calculator, a dose log and reminders. Free to download on iPhone.
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