Thymosin Alpha-1 dosing calculator

CompoundThymosin Alpha-1

Vial

Water

Your dose

1 mg = 1000 mcg.

Your syringe

Draw this much

Enter a vial size, water volume and dose to see where to pull.

0 units0.3 mL barrel, U-100 scale30 units

For tracking and calculation purposes only. Not medical advice. Based on a standard U-100 insulin syringe.

This calculator has no pre-filled dose for Thymosin Alpha-1. We pre-fill a dose only from an approved label or a human trial arm that fits this tool, and none does.

How the units are worked out

Your vial holds a fixed amount of peptide. The water you add sets the concentration (how much peptide sits in each millilitre). The concentration then decides how much liquid carries your dose.

Three steps, in order:

Concentration (mcg/mL) = peptide in the vial (mcg) divided by water added (mL).
Volume (mL) = your dose (mcg) divided by the concentration (mcg/mL).
Units to draw = volume (mL) multiplied by 100.

That last step is the syringe, not the peptide. A U-100 insulin syringe is marked so 100 units hold 1 mL, so 0.1 mL reads as 10 units.

A worked example

Enter your dose in the calculator above and this line shows the numbers worked through.

Water and units at a glance

Thymosin Alpha-1 at different mixes. Every row opens the calculator on that mix.

Vial	Water	Concentration
10 mg	1 mL	10,000 mcg/mL
10 mg	2 mL	5,000 mcg/mL
10 mg	3 mL	3,333 mcg/mL
10 mg	5 mL	2,000 mcg/mL

Units appear once you enter a dose.

The pre-filled vial size is the most-used size in WPA dosing data (Aug 2026), or our vendors' most common size where WPA data is thin. The water is the most-used amount in WPA data. There is no pre-filled dose. Not a recommendation.

Mixing and storage

Run the water down the inside wall of the vial and let the powder dissolve on its own. Never shake it. Label the vial with the compound, the total mass, the water you added, the concentration and the date. A sealed freeze-dried vial keeps 12 to 24 months in the fridge at 2 to 8°C. Once mixed with preserved water, such as bacteriostatic water, that drops to roughly 28 days refrigerated. Keep it at the back of the fridge, away from light and away from the door's temperature swings.

Other compounds

Questions

Does thymosin alpha-1 actually work?

It depends entirely on the condition. In chronic hepatitis B it is an approved medicine in many countries, and the trials back that. In sepsis the story is messier. An early trial in 361 patients found fewer deaths. A much larger placebo controlled trial in 1,106 patients, published in the BMJ in 2025, found no difference. So it does something in some conditions and nothing in others. No trial has tested it in healthy people.

Is it approved as a medicine anywhere?

Yes. The synthetic form is called thymalfasin. It is an approved prescription medicine in more than 30 countries outside the United States. Most of those approvals cover chronic hepatitis B, and some cover improving vaccine response in people with weakened immune systems. It is not approved by the FDA in the United States. Approval abroad means a regulator reviewed real trial data. It does not mean the peptide works for everything sold under its name.

Can I get it legally in the United States?

There is no FDA approved thymosin alpha-1 product in the United States. FDA also lists it on its page of bulk drug substances that may present significant safety risks in compounding, in the group whose nomination was withdrawn. FDA says its safety information is not adequate. Compounding it is not a route the agency has cleared. Anything sold outside a prescription is unregulated, and what is actually in the vial is unverified.

Will it boost my immune system if I am healthy?

Nobody knows, because nobody has tested it. Every trial on this page studied sick people: hepatitis B, sepsis, cancer, COVID-19. Those immune systems were damaged, suppressed or overwhelmed. Thymosin alpha-1 is a modulator, which means it pushes an unbalanced response back toward normal. There is no evidence that pushing an already normal immune system does anything useful. Treat healthy immune boosting claims as untested marketing.

What did the COVID-19 research actually show?

Mixed results, pulling in both directions. A 2023 pooling of eight studies found lower death rates in moderate to critical COVID-19 patients. The same analysis found no difference in ventilation needs or hospital stay. Pulling the other way, a study across five hospitals in Hubei found worse recovery in patients given it, especially the sickest. That study was not randomised, so those patients may have been sicker to begin with. The question is not settled.

What should I ask a doctor about it?

Ask what condition you would be treating, and whether a trial exists in that exact condition. Ask about liver blood tests, since mild enzyme swings turned up in hepatitis B trials. Ask where the product would come from, since there is no FDA approved version in the United States. Ask what happens if nothing changes. And ask whether an approved treatment for your condition already exists, because one usually does.