Peptide Guide + Calculator
Thymosin Alpha-1 Reconstitution Calculator & Guide
Thymalfasin / Immune-Modulating Peptide
Thymosin Alpha-1, also called thymalfasin, is a synthetic 28-amino-acid peptide investigated and used internationally as an immune-modulating therapy. It is not FDA-approved in the United States, although substantial human clinical research exists across infectious disease and immune-related settings. This guide explains the evidence, U.S. regulatory status, safety context, and educational concentration math.
Evidence Snapshot
Thymosin Alpha-1 research at a glance
Standardized regulatory and evidence context so research compounds, investigational drugs, and approved medications are not treated as if they have the same level of human evidence.
Regulatory status
Not FDA-approvedDevelopment / evidence stage
Phase 3 investigational
Primary mechanism
28-amino-acid immune-modulating peptide studied across infectious-disease and immune-related settings.
WADA context
No specific prohibition identifiedHuman intervention evidence
A large 2025 multicenter Phase 3 sepsis trial enrolled more than 1,100 adults and did not show a clear 28-day mortality benefit; older hepatitis trials produced mixed findings.
Human biology evidence
Multiple randomized human trials provide a substantially deeper clinical evidence base than exists for many research-market peptides.
Key takeaway
Thymosin Alpha-1 has substantial human research, including a negative large Phase 3 sepsis trial, but no FDA-approved U.S. therapeutic indication.
Evidence labels describe the research base and regulatory context; they are not treatment, dosing, or use recommendations. Review dates describe the last BACToBasics source check for this evidence summary. Anti-doping rules can change and should be verified with the applicable authority.
Thymosin Alpha-1 Reconstitution Calculator
Enter the vial amount, liquid volume, and amount you want to calculate. BACToBasics will automatically calculate concentration, liquid volume, and U-100 syringe-unit equivalents.
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Calculator values are educational math inputs only. They are not recommended preparation amounts, doses, or use protocols.
Thymosin Alpha-1 Reconstitution Math
Reconstitution math starts with the amount contained in the vial and the liquid volume used in the calculation. Dividing the vial amount by the liquid volume gives the resulting concentration.
Example vial amount
10 mg
| Liquid Volume | Calculation | Concentration |
|---|---|---|
| 1 mL | 10 mg ÷ 1 mL | 10 mg/mL |
| 2 mL | 10 mg ÷ 2 mL | 5 mg/mL |
| 3 mL | 10 mg ÷ 3 mL | 3.3333 mg/mL |
This table demonstrates concentration math only. The liquid volumes shown are examples for comparison and are not preparation recommendations.
More Reconstitution Tools
Need to compare different liquid volumes or convert between mg, mcg, mL, and U-100 units? Use the dedicated BACToBasics calculator tools.
What is Thymosin Alpha-1?
Thymosin Alpha-1 is a 28-amino-acid peptide derived from prothymosin alpha biology and is also known by the generic drug name thymalfasin. It has been studied as an immune modulator affecting T-cell function, dendritic-cell activity, and innate immune signaling.
U.S. regulatory status
Thymalfasin is not FDA-approved for therapeutic use in the United States. FDA orphan-drug records show designations for conditions such as chronic hepatitis B, hepatocellular carcinoma, and DiGeorge anomaly, but those designations did not result in FDA approval for those indications.
Human clinical evidence exists
Unlike many research peptides discussed online, Thymosin Alpha-1 has been tested in multiple randomized human trials. Older studies evaluated chronic hepatitis B and C, and later trials have studied severe infections, sepsis, and COVID-19. The existence of human trials does not mean that every proposed immune or wellness use is established.
What did the 2025 Phase 3 sepsis trial show?
The large multicenter TESTS Phase 3 trial enrolled more than 1,100 adults with sepsis. It found no clear evidence that Thymosin Alpha-1 reduced 28-day all-cause mortality compared with placebo. This is an important example of why promising immune-modulating biology and smaller earlier studies do not guarantee a successful large confirmatory trial.
Thymosin Alpha-1 and hepatitis research
Randomized trials in chronic hepatitis B have reported mixed results, including some signals of virologic response in certain studies and nonsignificant primary comparisons in others. These historical programs support real human exposure and research depth but do not create a current FDA-approved U.S. indication.
Safety context
Clinical trials generally provide more safety information for Thymosin Alpha-1 than exists for many unapproved research peptides, but safety remains indication-, formulation-, population-, and product-specific. Research findings should not be generalized to unverified peptide products or self-directed immune treatment.
Thymosin Alpha-1 reconstitution math
BACToBasics can calculate concentration from user-entered vial mass and liquid volume. The calculator does not provide a therapeutic regimen, replace product-specific instructions used in countries where thymalfasin products are authorized, or imply FDA approval in the United States.
Explore more about Thymosin Alpha-1
7 linksComparisons, research records, development tracking, blends, and related guides are available here when you want to go deeper.
Explore more about Thymosin Alpha-1
7 linksComparisons, research records, development tracking, blends, and related guides are available here when you want to go deeper.
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Relevant glossary concepts
Definitions are matched against the guide's structured title, subtitle, description, and educational sections.
FDA-Approved
A status indicating that the FDA has approved a specific drug product for one or more labeled uses after reviewing the required evidence and manufacturing information.
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GlossaryConcentration
The amount of a substance contained in a given volume of liquid, such as mg/mL or mcg/mL.
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GlossaryPeptide
A chain of amino acids linked by peptide bonds.
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Thymosin Alpha-1 FAQ
Tap a question to expand only the answer you want to read.
Is Thymosin Alpha-1 FDA-approved in the United States?
No. Thymalfasin has FDA orphan-drug designations but is not FDA-approved for therapeutic use in the United States.
Does Thymosin Alpha-1 have human trial data?
Yes. It has been studied in multiple randomized human trials, including hepatitis, severe infection, COVID-19, and a large Phase 3 sepsis trial.
Did the large sepsis trial show a mortality benefit?
No. The 2025 TESTS Phase 3 trial found no clear reduction in 28-day all-cause mortality versus placebo.
Is Thymosin Alpha-1 the same as TB-500?
No. Thymosin Alpha-1 and TB-500 are completely different peptides with different sequences, biology, evidence bases, and regulatory contexts.
Does BACToBasics recommend Thymosin Alpha-1 for immune support?
No. BACToBasics summarizes evidence and provides concentration math but does not recommend treatment, dosing, or self-directed immune modulation.
Sources & References
3 sourcesOpen the references when you want to inspect the research and regulatory sources behind this guide.
Sources & References
3 sourcesOpen the references when you want to inspect the research and regulatory sources behind this guide.
FDA records showing orphan designations without U.S. approval for listed indications.
Large multicenter randomized placebo-controlled Phase 3 trial in adults with sepsis.
Randomized controlled human trial evaluating Thymosin Alpha-1 in chronic hepatitis B.
BACToBasics provides educational information and math tools only. This content is not medical advice, dosing advice, injection instruction, or a recommendation to use any peptide or medication.