Thymosin Alpha-1

Thymosin Alpha-1 (Thymalfasin) Research Peptide – Immune Modulation, T-Cell Signaling & Host Defense Research

Synthetic 28-Amino-Acid Peptide for Adaptive Immunity, Dendritic Cell Biology, Toll-Like Receptor Signaling, Viral Immunology & Cancer Immunology Research

Thymosin Alpha-1 (Tα1), also known as Thymalfasin, is a naturally occurring, N-terminally acetylated 28-amino-acid peptide associated with immune system regulation.

Originally isolated from thymosin fraction 5, Thymosin Alpha-1 has become an important subject of immunological research because of its interactions with cellular pathways involved in innate and adaptive immunity.

Unlike peptides primarily investigated for metabolic regulation or tissue remodeling, Thymosin Alpha-1 is studied for its immunomodulatory properties, including effects on T lymphocytes, dendritic cells, cytokine signaling and host defense responses.

Thymosin Alpha-1 has been evaluated in clinical studies involving chronic viral hepatitis, sepsis, cancer-related immune responses and other conditions associated with immune dysfunction.

The pharmaceutical form, thymalfasin, has been marketed under the name Zadaxin in certain countries.

However, Thymosin Alpha-1 is not an FDA-approved medicine in the United States, and its regulatory status varies internationally.

Clinical evidence is indication-specific and does not establish that Thymosin Alpha-1 universally improves immunity or prevents infection.

ICAME Pharmacy Thymosin Alpha-1 is intended exclusively for legitimate laboratory research and development purposes.

FOR RESEARCH USE ONLY — NOT FOR HUMAN OR VETERINARY USE.

What Is Thymosin Alpha-1?

Thymosin Alpha-1 is an endogenous peptide consisting of 28 amino acid residues.

It was originally identified during investigations of thymus-associated peptides and immune regulation.

The peptide is produced from the precursor protein prothymosin alpha and has been studied for its capacity to influence immune cell signaling.

Its research applications include:

• T-cell biology

• Adaptive immune responses

• Innate immune signaling

• Dendritic cell function

• Toll-like receptor-associated pathways

• Cytokine regulation

• Immune cell differentiation

• Antigen presentation

• Viral immunology

• Hepatitis B and hepatitis C research

• Sepsis-associated immune dysfunction

• Cancer immunology

• Immune exhaustion

• Vaccine response research

• Immunosenescence

• Peptide structure–activity relationships

Thymosin Alpha-1 is best described as an immunomodulatory peptide, rather than a universal immune stimulant.

Its effects can differ according to the biological model, immune status and experimental conditions.

Thymosin Alpha-1 Molecular Structure and Chemical Properties

Thymosin Alpha-1 is a linear peptide containing 28 amino acids.

Its naturally occurring structure includes an N-terminal acetyl group.

Molecular Characteristics

The molecular formula and molecular weight refer to the defined N-acetylated peptide.

Acetate-containing preparations may have different overall compositions depending on their counterion content.

Thymosin Alpha-1 Amino Acid Sequence

The complete 28-amino-acid sequence is:

Ac–Ser–Asp–Ala–Ala–Val–Asp–Thr–Ser–Ser–Glu–Ile–Thr–Thr–Lys–Asp–Leu–Lys–Glu–Lys–Lys–Glu–Val–Val–Glu–Glu–Ala–Glu–Asn–OH

One-Letter Amino Acid Sequence

Ac-SDAAVDTSSEITTKDLKEKKEVVEEAEN-OH

The N-terminal acetyl group is an important structural feature.

Molecular Characteristics

28 amino acid residues

Linear peptide structure

N-terminal acetylation

Free C-terminal carboxyl group

No disulfide bridges

Highly polar amino acid composition

Multiple acidic and basic residues

The peptide's chemical structure is distinct from Thymosin Beta-4, TB-500 and Thymosin Alpha-11.

What Is the Thymus?

The thymus is a primary lymphoid organ involved in T-cell development.

It is located in the upper chest, behind the sternum.

The thymus provides a specialized environment in which developing T lymphocytes undergo selection and maturation.

Principal Thymic Functions

T-cell development

Immune tolerance

Selection of functional T cells

Elimination of strongly self-reactive T cells

Adaptive immune system development

Establishment of a diverse T-cell repertoire

Thymosin Alpha-1 was originally identified in the context of thymus-derived peptide research.

However, the peptide's biological effects should not be interpreted as proof that it regenerates the thymus or reverses age-related thymic involution in humans.

How Does Thymosin Alpha-1 Work?

Thymosin Alpha-1 has been investigated as a regulator of innate and adaptive immune responses.

Its biological effects involve interactions with immune signaling pathways, including Toll-like receptor-associated responses and downstream cytokine networks.

Unlike receptor agonists such as GLP-1 peptides, Thymosin Alpha-1 does not have one universally established, exclusive cell-surface receptor that fully explains all reported effects.

Simplified Research Mechanism

Thymosin Alpha-1 (Tα1)

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Immune Cell Signaling Modulation

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Toll-Like Receptor-Associated Pathways

↓

Dendritic Cell and Antigen-Presentation Responses

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T-Cell-Associated Immune Regulation

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Changes in Cytokine Signaling and Host Defense Responses

The precise response depends on the cell type, experimental model and disease context.

It would be inaccurate to describe Thymosin Alpha-1 as always increasing immune activity.

Some experimental findings suggest context-dependent modulation of inflammatory and regulatory responses.

Thymosin Alpha-1 and Innate Immunity

Innate immunity provides an early response to pathogens and cellular damage.

It involves immune cells and molecular recognition systems that detect potentially harmful stimuli.

Relevant components include:

Dendritic cells

Macrophages

Monocytes

Natural killer cells

Pattern-recognition receptors

Cytokine signaling

Antimicrobial defense mechanisms

Thymosin Alpha-1 has been investigated for its influence on selected innate immune responses.

Research Areas

Innate immune activation

Pattern-recognition receptor signaling

Dendritic cell maturation

Macrophage-associated responses

Cytokine expression

Host defense signaling

Inflammatory regulation

The magnitude and direction of these effects may vary across experimental systems.

Thymosin Alpha-1 and Adaptive Immunity

Adaptive immunity involves antigen-specific responses mediated primarily by T and B lymphocytes.

Thymosin Alpha-1 has been studied for effects on cellular immune responses.

Research Areas

T-cell differentiation

T-cell activation

Antigen-specific responses

Helper T-cell signaling

Cytotoxic T-cell function

Immune memory

Immune exhaustion

Antigen presentation

The peptide has attracted interest in settings where immune cell function may be impaired or dysregulated.

However, laboratory immune changes do not necessarily translate into improved clinical outcomes.

Thymosin Alpha-1 and T-Cell Research

T lymphocytes are central components of adaptive immunity.

Different T-cell populations perform specialized functions.

CD4+ T Cells

CD4+ T cells coordinate immune responses through cytokine production and interactions with other immune cells.

CD8+ T Cells

CD8+ T cells recognize and eliminate certain infected or abnormal cells.

Regulatory T Cells

Regulatory T cells help control excessive immune responses and maintain immune tolerance.

Thymosin Alpha-1 Research Endpoints

CD4+ T-cell populations

CD8+ T-cell populations

T-cell activation markers

Cytokine secretion

T-cell differentiation

Immune exhaustion markers

Antigen-specific responses

Changes in these biomarkers should be interpreted within the context of the experimental model.

Thymosin Alpha-1 and Dendritic Cell Research

Dendritic cells are professional antigen-presenting cells.

They help connect innate and adaptive immunity.

Dendritic cells process antigens and present them to T lymphocytes.

Research Areas

Dendritic cell maturation

Antigen presentation

Costimulatory molecule expression

Cytokine production

T-cell priming

Toll-like receptor signaling

Immune response coordination

Thymosin Alpha-1 has been investigated for its effects on dendritic cell-associated immune signaling.

These findings provide a basis for research into host defense and immune modulation.

Thymosin Alpha-1 and Toll-Like Receptors

Toll-like receptors, or TLRs, are pattern-recognition receptors involved in innate immune responses.

They detect molecular patterns associated with pathogens and tissue damage.

Different TLRs recognize different biological stimuli.

Relevant Signaling Pathways

TLR2-associated signaling

TLR4-associated signaling

TLR9-associated signaling

MyD88-dependent signaling

NF-κB activation

Interferon-associated responses

Cytokine production

Experimental literature has investigated relationships between Thymosin Alpha-1 and TLR-associated pathways.

However, these interactions should not be described as a single, fully established direct receptor-binding mechanism.

Thymosin Alpha-1 and NF-κB Signaling

NF-κB is a family of transcription factors involved in immune and inflammatory responses.

It regulates expression of numerous genes associated with cellular defense.

Research Areas

Inflammatory gene expression

Cytokine regulation

Immune cell activation

Pattern-recognition receptor signaling

Cell survival pathways

Host defense responses

Thymosin Alpha-1 may influence NF-κB-associated signaling in certain experimental models.

Its effects are context-dependent.

Thymosin Alpha-1 and Cytokine Research

Cytokines are signaling proteins that coordinate immune responses.

Thymosin Alpha-1 has been investigated for effects on cytokine-associated pathways.

Research Targets

Interleukin-2

Interleukin-6

Interleukin-10

Interleukin-12

Interferon-gamma

Tumor necrosis factor-alpha

Type I interferon-associated responses

Cytokine changes may reflect immune activation, immune regulation or inflammatory responses.

A higher cytokine concentration is not automatically beneficial.

Excessive inflammatory signaling can be harmful.

Thymosin Alpha-1 and Interferon Research

Interferons are cytokines involved in antiviral defense and immune regulation.

Thymosin Alpha-1 has been investigated alongside interferon-related pathways.

Research Areas

Antiviral signaling

Interferon-associated gene expression

Immune cell responses

Host defense pathways

Antigen presentation

Viral immunology

Clinical research has also investigated thymalfasin in combination with interferon-based treatments for chronic viral hepatitis.

However, the results do not establish Thymosin Alpha-1 as a substitute for modern antiviral medicines.

Thymosin Alpha-1 and Viral Immunology

Viral infections activate innate and adaptive immune mechanisms.

Thymosin Alpha-1 has been studied in several viral disease contexts.

Research Areas

Host antiviral responses

T-cell function

Interferon signaling

Antigen presentation

Immune exhaustion

Inflammatory regulation

Viral hepatitis research

Respiratory infection research

Thymosin Alpha-1 should not be described as a broadly proven antiviral medicine.

Its clinical effects depend on the specific disease and treatment setting.

Thymosin Alpha-1 and Hepatitis B Research

Chronic hepatitis B is a viral infection affecting the liver.

Immune responses play an important role in viral persistence and disease progression.

Thymalfasin has been investigated in clinical studies involving chronic hepatitis B.

Research Endpoints

HBV DNA

ALT normalization

HBeAg seroconversion

HBsAg-related outcomes

T-cell-associated immune responses

Long-term virological responses

Thymalfasin has received marketing authorization for chronic hepatitis B in certain jurisdictions.

Important Limitation

International approvals do not establish FDA approval in the United States.

Modern hepatitis B treatment guidelines emphasize antiviral therapies with well-established efficacy.

Thymosin Alpha-1 should not be presented as a universal replacement for guideline-directed antiviral treatment.

Thymosin Alpha-1 and Hepatitis C Research

Hepatitis C is caused by the hepatitis C virus.

Thymalfasin was historically investigated as an adjunct to interferon-based therapy.

Research Areas

Viral clearance

Interferon-associated immune responses

T-cell function

Liver inflammation

Treatment response

However, the treatment landscape has changed substantially.

Modern direct-acting antiviral regimens can cure most hepatitis C infections.

Thymosin Alpha-1 is not a substitute for these established treatments.

Thymosin Alpha-1 and Sepsis Research

Sepsis is a life-threatening condition involving organ dysfunction caused by a dysregulated host response to infection.

Sepsis can involve both excessive inflammation and impaired immune function.

Thymosin Alpha-1 has been investigated as an immunomodulatory treatment candidate.

Research Areas

Sepsis-associated immunosuppression

T-cell dysfunction

Lymphopenia

Inflammatory biomarkers

Immune exhaustion

28-day mortality

Organ dysfunction

Immune response heterogeneity

The clinical evidence is mixed.

Thymosin Alpha-1 Phase 3 Sepsis Research: TESTS Trial

The TESTS trial, published in The BMJ in 2025, was a multicenter, double-blind, randomized, placebo-controlled phase 3 study.

The study enrolled 1,106 adults with sepsis across 22 centers in China.

The modified intention-to-treat analysis included 1,089 participants.

Primary Outcome: 28-Day All-Cause Mortality

The hazard ratio was 0.97, with a 95% confidence interval of 0.76–1.24.

The difference was not statistically significant.

Scientific Interpretation

The large phase 3 trial did not demonstrate an overall 28-day mortality benefit.

This is an important limitation when evaluating claims that Thymosin Alpha-1 improves survival in sepsis.

Further research may investigate whether particular biological subgroups respond differently.

However, subgroup hypotheses require prospective confirmation.

Thymosin Alpha-1 Sepsis Meta-Analysis

A 2025 systematic review and meta-analysis evaluated randomized controlled trials of Thymosin Alpha-1 in sepsis.

The analysis included 11 randomized trials involving 1,927 participants.

Overall Findings

The pooled analysis suggested lower 28-day mortality in Thymosin Alpha-1-treated groups.

The reported odds ratio was approximately 0.73, with a 95% confidence interval of 0.59–0.90.

Important Limitations

When analyses were restricted to higher-quality studies or multicenter studies, the mortality benefit was not statistically significant.

Trial sequential analysis suggested that the evidence remained insufficient for a definitive conclusion.

Research Interpretation

The findings are hypothesis-generating rather than proof of a universal mortality benefit.

Large, well-controlled studies are particularly important when assessing clinically meaningful outcomes.

Thymosin Alpha-1 and Cancer Immunology

Cancer immunology examines how immune cells recognize and respond to malignant cells.

Thymosin Alpha-1 has been investigated as a potential immunomodulatory adjunct in oncology.

Research Areas

T-cell responses

Dendritic cell function

Antigen presentation

Tumor microenvironment

Immune exhaustion

Cancer-associated immunosuppression

Treatment-associated immune effects

Combination therapy research

Thymosin Alpha-1 has been studied in various cancer settings.

However, it is not established as a universal anticancer treatment.

Thymosin Alpha-1 and the Tumor Microenvironment

The tumor microenvironment includes cancer cells, immune cells, stromal cells and signaling molecules.

Immune responses within this environment can influence disease progression and treatment response.

Research Areas

Tumor-associated immune cells

Cytotoxic T-cell activity

Regulatory T-cell responses

Dendritic cell signaling

Inflammatory mediators

Immune suppression

Antigen presentation

Changes in immune biomarkers do not necessarily demonstrate improved cancer survival.

Clinical benefit requires appropriately designed trials.

Thymosin Alpha-1 and Immune Checkpoint Research

Immune checkpoint pathways regulate T-cell activity.

Examples include PD-1, PD-L1 and CTLA-4-associated signaling.

Thymosin Alpha-1 has attracted research interest in combination immunotherapy settings.

Experimental Questions

Can immune cell function be modified?

How are exhausted T-cell populations affected?

Are antigen-presenting cell responses altered?

Can immune signaling influence treatment response?

What are the safety implications of combination therapy?

Thymosin Alpha-1 is not an approved replacement for immune checkpoint inhibitors.

Thymosin Alpha-1 and Chemotherapy-Associated Immune Dysfunction

Some anticancer treatments can suppress immune cell populations.

Thymosin Alpha-1 has been investigated for potential effects on immune recovery and immune-related biomarkers.

Research Areas

Lymphocyte counts

T-cell-associated responses

Immune suppression

Inflammatory markers

Infection-related outcomes

Treatment tolerability

The evidence varies across cancer types and study designs.

Improvement in immune cell counts does not necessarily establish better cancer outcomes.

Thymosin Alpha-1 and Vaccine Response Research

Vaccines stimulate antigen-specific immune responses.

Thymosin Alpha-1 has been investigated as an immunomodulatory adjunct in selected vaccine studies.

Research Areas

Antibody responses

T-cell responses

Antigen presentation

Vaccine-associated cytokines

Immune memory

Immunosenescence

Responses in immunocompromised populations

However, Thymosin Alpha-1 has not been established as a universally effective vaccine enhancer.

Thymosin Alpha-1 and Immunosenescence

Immunosenescence refers to age-associated changes in immune function.

These changes may involve:

Altered T-cell populations

Reduced naive T-cell diversity

Changes in inflammatory signaling

Impaired responses to some infections

Changes in vaccine responses

Altered immune regulation

Thymosin Alpha-1 has been investigated in immune-aging research.

Important Limitation

The peptide has not been demonstrated to reverse biological aging or restore youthful immune function in humans.

Thymosin Alpha-1 and Autoimmune Research

Autoimmune diseases involve inappropriate immune responses against components of the body.

Because Thymosin Alpha-1 influences immune signaling, it has been investigated in selected immune-regulation models.

Research Areas

Immune tolerance

Regulatory T-cell responses

Inflammatory cytokines

T-cell differentiation

Innate immune regulation

Autoimmune-associated signaling

However, immune modulation can produce different effects depending on disease context.

Thymosin Alpha-1 should not be described as a proven treatment for autoimmune diseases generally.

Thymosin Alpha-1 and Allergic Inflammation Research

Allergic inflammation involves immune responses to otherwise harmless substances.

Relevant biological pathways include T-helper-cell differentiation and cytokine signaling.

Research Areas

T-cell polarization

Cytokine responses

Immune tolerance

Inflammatory signaling

Dendritic cell function

Experimental allergic inflammation

The clinical relevance of Thymosin Alpha-1 in allergic disease remains insufficiently established.

Thymosin Alpha-1 and Respiratory Infection Research

Respiratory infections involve complex interactions between pathogens and host immune responses.

Thymosin Alpha-1 has been investigated in respiratory disease settings, including COVID-19.

Research Areas

Lymphocyte responses

T-cell dysfunction

Inflammatory biomarkers

Immune exhaustion

Host defense

Clinical outcomes

Important Limitation

COVID-19 research findings have been heterogeneous.

Thymosin Alpha-1 is not established as a standard treatment or preventive medicine for COVID-19.

Thymosin Alpha-1 and Immune Exhaustion

Immune exhaustion describes altered functional states that can arise during persistent antigen exposure.

It is relevant to chronic infection and cancer immunology.

Research Areas

PD-1 expression

T-cell functional responses

Cytokine production

Chronic antigen stimulation

Immune checkpoint signaling

T-cell differentiation

Thymosin Alpha-1 has been investigated in models involving dysfunctional T-cell responses.

However, the peptide has not been proven to reverse immune exhaustion in every disease setting.

Thymosin Alpha-1 and Natural Killer Cell Research

Natural killer cells are innate lymphocytes involved in host defense.

They can recognize and respond to certain infected or abnormal cells.

Research Areas

NK-cell activity

Cytotoxic signaling

Immune cell interactions

Cytokine-associated responses

Host defense mechanisms

Thymosin Alpha-1 has been studied in relation to NK-cell-associated immune activity.

These findings remain context-dependent.

Thymosin Alpha-1 and Macrophage Research

Macrophages participate in innate immunity, tissue homeostasis and inflammatory responses.

Research Areas

Pattern-recognition signaling

Cytokine production

Phagocytosis-associated responses

Inflammatory regulation

Immune cell communication

Tissue-specific immune responses

Thymosin Alpha-1 may be investigated for its effects on macrophage-associated signaling.

However, it should not be characterized as universally activating or suppressing macrophages.

Thymosin Alpha-1 vs. Thymosin Beta-4

Despite their similar names, Thymosin Alpha-1 and Thymosin Beta-4 are different peptides.

The biological effects of one peptide should not be attributed to the other.

Thymosin Alpha-1 vs. TB-500

TB-500 is commonly identified as a seven-amino-acid fragment of Thymosin Beta-4.

Thymosin Alpha-1 is a separate 28-amino-acid peptide.

Thymosin Alpha-1

Research focus: Immune signaling and immunomodulation.

TB-500

Research focus: Thymosin Beta-4-derived actin-associated fragment biology.

These peptides differ in sequence, structure and scientific evidence.

They are not interchangeable.

Thymosin Alpha-1 vs. Thymosin Alpha-11

Thymosin Alpha-11 is a different peptide related to Thymosin Alpha-1.

Thymosin Alpha-11 contains seven additional C-terminal amino acids.

The two molecules should be analytically distinguished.

Thymosin Alpha-1 vs. LL-37

LL-37 is a human antimicrobial peptide derived from cathelicidin.

Thymosin Alpha-1 is an immunomodulatory peptide.

Thymosin Alpha-1

Immune cell signaling and immune regulation research

LL-37

Antimicrobial peptide biology and host defense research

Their structures and mechanisms differ substantially.

Thymosin Alpha-1 vs. KPV

KPV is a tripeptide derived from the C-terminal region of alpha-melanocyte-stimulating hormone.

Thymosin Alpha-1 is a 28-amino-acid peptide associated with immune regulation.

Thymosin Alpha-1 vs. BPC-157

BPC-157 is a synthetic 15-amino-acid peptide investigated primarily in preclinical tissue injury models.

Thymosin Alpha-1 is a 28-amino-acid immunomodulatory peptide with a distinct clinical research history.

Main Difference

Thymosin Alpha-1: Immune system signaling and host defense research.

BPC-157: Experimental tissue injury and repair-associated signaling.

Neither peptide should be presented as a universal treatment for inflammation or injury.

Thymosin Alpha-1 and Pharmaceutical Development

Thymalfasin is a synthetic version of Thymosin Alpha-1.

It has been developed as a pharmaceutical product in certain international markets.

Zadaxin

Zadaxin is a brand name associated with thymalfasin.

It has been marketed in certain countries for specific immune-related indications.

Important Regulatory Distinction

International marketing authorization does not establish FDA approval.

The regulatory status of thymalfasin varies by jurisdiction.

Approved pharmaceutical products also have manufacturing and quality requirements that differ from research-grade peptides.

Thymosin Alpha-1 FDA Regulatory Status

As of October 2026, Thymosin Alpha-1 is not an FDA-approved medicine in the United States.

The presence of thymalfasin products in international markets does not change this status.

Important Distinctions

Clinical Research: Thymosin Alpha-1 has been evaluated in human clinical studies.

International Pharmaceutical Products: Approved formulations exist in certain jurisdictions.

US FDA Approval: No FDA-approved Thymosin Alpha-1 medicine.

ICAME Pharmacy Research Product: Not an approved pharmaceutical product.

Research-grade Thymosin Alpha-1 should not be described as equivalent to Zadaxin or other prescription formulations.

Thymosin Alpha-1 Safety Considerations

Thymosin Alpha-1 has been investigated in clinical trials.

However, safety findings depend on the specific formulation, study population and clinical setting.

Potential Safety Considerations

Hypersensitivity reactions

Injection-site reactions in clinical formulations

Immune-related effects

Changes in inflammatory signaling

Uncertain effects in autoimmune conditions

Potential interactions with immunomodulatory treatments

Insufficient long-term safety data in some populations

Product impurity and formulation risks

Important Limitation

Clinical safety findings involving pharmaceutical thymalfasin cannot establish the safety of research-grade products.

Research preparations may differ in purity, impurity profiles, formulation, sterility and manufacturing controls.

Thymosin Alpha-1 and Immune Balance

Immune regulation involves maintaining a balance between effective host defense and excessive inflammation.

Both insufficient and excessive immune activity can cause harm.

Research Areas

Immune activation

Immune tolerance

Inflammatory regulation

Antigen presentation

Cytokine balance

T-cell responses

Innate–adaptive immune interactions

Thymosin Alpha-1 should not be described simply as increasing immunity.

Its effects depend on biological context.

Thymosin Alpha-1 Peptide Stability

Thymosin Alpha-1 is a synthetic peptide susceptible to chemical and physical degradation.

Research Considerations

Hydrolysis

Deamidation

Oxidation

Aggregation

Adsorption

Temperature-associated degradation

pH-dependent changes

Counterion effects

Impurity formation

Validated stability data are required to establish product-specific laboratory storage conditions.

Thymosin Alpha-1 Analytical Characterization

Reliable scientific research requires accurate peptide identification.

Essential Quality Parameters

Complete peptide sequence

N-terminal acetylation

Molecular formula

Molecular mass

Peptide purity

Peptide content

Counterion composition

Related peptide impurities

Degradation products

Batch-specific documentation

The acetate form should be distinguished from the defined parent peptide when reporting chemical composition.

High-Performance Liquid Chromatography

HPLC can be used to evaluate Thymosin Alpha-1 purity.

Research Applications

Chromatographic purity

Related substance analysis

Degradation monitoring

Batch consistency

Method development

A high HPLC purity percentage does not independently establish correct molecular identity or suitability for clinical use.

Liquid Chromatography–Mass Spectrometry

LC-MS can help verify the molecular mass of Thymosin Alpha-1.

The expected average molecular weight of the defined N-acetylated peptide is approximately 3,108.3 g/mol.

Mass spectrometry may also assist in detecting degradation products and related impurities.

Analytical findings should be interpreted alongside sequence information and other characterization data.

Peptide Content Analysis

Peptide content is distinct from chromatographic purity.

A preparation may contain:

The principal peptide

Counterions

Residual water

Non-peptide material

Other impurities

Accurate peptide content is important for quantitative laboratory research.

Certificate of Analysis

A batch-specific Certificate of Analysis should include:

• Product identity

• Batch or lot number

• Complete amino acid sequence

• N-terminal acetylation

• Molecular formula

• Molecular weight

• Peptide purity

• Peptide content

• Counterion composition

• Analytical methods

• Related impurities

• Stability-related information

A COA does not establish clinical efficacy, sterility or suitability for human administration.

Scientific Evidence: Established Findings and Limitations

Established Scientific Facts

• Thymosin Alpha-1 is a 28-amino-acid peptide.

• It is naturally N-terminally acetylated.

• Its pharmaceutical name is thymalfasin.

• It has been studied in immune system regulation.

• Experimental research has investigated T-cell and dendritic cell-associated responses.

• Toll-like receptor-associated pathways are relevant to its proposed immunomodulatory mechanisms.

• Human clinical studies have been conducted in viral hepatitis, sepsis and other conditions.

• Pharmaceutical thymalfasin products have been marketed in certain countries.

• Thymosin Alpha-1 is not FDA-approved in the United States.

• The large TESTS sepsis trial did not demonstrate a statistically significant overall 28-day mortality benefit.

Important Scientific Limitations

• Thymosin Alpha-1 is not a universal immune booster.

• Its effects are context-dependent.

• It is not established as a universal antiviral medicine.

• It is not an approved US treatment for chronic viral hepatitis.

• It is not a proven standalone cancer therapy.

• Sepsis survival benefits remain uncertain.

• It is not established as a general COVID-19 treatment.

• It is not proven to reverse immune aging.

• It is not established as a universal vaccine enhancer.

• Long-term clinical outcomes vary by indication.

• Research-grade products are not equivalent to approved pharmaceutical formulations.

• ICAME Pharmacy Thymosin Alpha-1 is not intended for human administration.

Potential Thymosin Alpha-1 Research Applications

Thymosin Alpha-1 may be relevant to appropriately controlled laboratory investigations involving:

• T-cell biology

• Adaptive immunity

• Innate immunity

• Dendritic cell function

• Antigen presentation

• Toll-like receptor signaling

• NF-κB-associated pathways

• Cytokine regulation

• Interferon-associated signaling

• Immune cell differentiation

• Immune exhaustion

• Natural killer cell research

• Macrophage signaling

• Host defense biology

• Viral immunology

• Hepatitis research

• Sepsis-associated immune dysfunction

• Cancer immunology

• Tumor microenvironment

• Vaccine response research

• Immunosenescence

• Immune tolerance

• Peptide stability

• Peptide analytical characterization

These research areas do not establish therapeutic benefits for ICAME Pharmacy research products.

Thymosin Alpha-1 Research Overview

Compound Name: Thymosin Alpha-1

Pharmaceutical Name: Thymalfasin

Alternative Name: Tα1 / TA1

Classification: Immunomodulatory Peptide

Peptide Length: 28 Amino Acids

Sequence: Ac-SDAAVDTSSEITTKDLKEKKEVVEEAEN-OH

Molecular Formula: C₁₂₉H₂₁₅N₃₃O₅₅

Molecular Weight: Approximately 3,108.3 g/mol

CAS Numbers: 62304-98-7; 69521-94-4

PubChem CID: 16130571

Structural Modification: N-Terminal Acetylation

Primary Research Focus: Immune System Regulation

Research Areas: T Cells / Dendritic Cells / Toll-Like Receptors / Viral Immunology / Cancer Immunology

Clinical Development: Human Clinical Studies Conducted

US FDA Status: Not Approved

International Status: Pharmaceutical Products Approved in Certain Countries

ICAME Product Status: Research Use Only

ICAME Pharmacy Product Information

Product Name: Thymosin Alpha-1

Alternative Name: Thymalfasin

Brand: ICAME Pharmacy

Product Category: Research Peptide

Research Classification: Synthetic Immunomodulatory Peptide

Research Areas: Immunology / T-Cell Biology / Dendritic Cell Signaling / Host Defense Research

Intended Use: Laboratory Research & Development Only

Product Quality Documentation

Product specifications should be verified using batch-specific analytical documentation.

Relevant parameters include:

• Verified amino acid sequence

• N-terminal acetylation

• Molecular mass

• Peptide purity

• Peptide content

• Counterion composition

• Related impurities

• Analytical methods

• Batch-specific Certificate of Analysis

• Stability information

No claims of pharmaceutical equivalence, sterility, injectable suitability or clinical efficacy should be made without appropriate supporting documentation and regulatory authorization.

Important Research Use Notice

FOR RESEARCH USE ONLY (RUO)

This ICAME Pharmacy product is intended exclusively for legitimate laboratory, analytical and scientific research purposes.

Not for human or veterinary use. Not for diagnostic, therapeutic, infection prevention, immune enhancement, cancer treatment, bodybuilding, athletic performance enhancement or other clinical purposes. Not for direct administration to humans or animals.

Thymosin Alpha-1 is an immunomodulatory peptide that has been investigated in experimental and clinical research.

Pharmaceutical thymalfasin products have received marketing authorization in certain international jurisdictions.

However, Thymosin Alpha-1 is not an FDA-approved medicine in the United States as of October 2026.

ICAME Pharmacy Thymosin Alpha-1 is not Zadaxin and is not an approved pharmaceutical product.

Clinical findings involving pharmaceutical thymalfasin formulations do not establish the safety, efficacy or suitability of research-grade Thymosin Alpha-1 for human administration.

Information presented on this page is intended solely for scientific and educational purposes and does not constitute medical advice, prescribing information, dosage guidance or instructions for human use.

About ICAME Pharmacy

ICAME Pharmacy provides specialized research products for professional laboratory and scientific applications.

Our portfolio focuses on compounds relevant to peptide science, immunology, molecular biology, receptor signaling and analytical chemistry.

We emphasize accurate product identification, responsible research use, scientific transparency and clear communication of evidence limitations.

For batch-specific analytical documentation and product inquiries, please contact ICAME Pharmacy.

Frequently Asked Questions About Thymosin Alpha-1

What is Thymosin Alpha-1?

Thymosin Alpha-1 is a naturally occurring, N-terminally acetylated 28-amino-acid peptide investigated for immune-modulating properties.

What is another name for Thymosin Alpha-1?

Thymalfasin.

What is Zadaxin?

Zadaxin is a pharmaceutical brand name associated with thymalfasin in certain countries.

How many amino acids does Thymosin Alpha-1 contain?

28 amino acids.

What is the molecular formula of Thymosin Alpha-1?

C₁₂₉H₂₁₅N₃₃O₅₅.

What is the molecular weight of Thymosin Alpha-1?

Approximately 3,108.3 g/mol.

What is the CAS number of Thymosin Alpha-1?

PubChem lists 62304-98-7 and 69521-94-4.

What is the PubChem CID of Thymosin Alpha-1?

What is the amino acid sequence of Thymosin Alpha-1?

Ac-SDAAVDTSSEITTKDLKEKKEVVEEAEN-OH.

Is Thymosin Alpha-1 the same as Thymosin Beta-4?

No. Thymosin Alpha-1 contains 28 amino acids and is primarily investigated in immunology, while Thymosin Beta-4 contains 43 amino acids and is associated with actin biology.

Is Thymosin Alpha-1 the same as TB-500?

No. TB-500 is commonly identified as a seven-amino-acid fragment of Thymosin Beta-4.

Does Thymosin Alpha-1 activate T cells?

Experimental research has investigated effects on T-cell-associated immune responses, but results depend on biological context.

Does Thymosin Alpha-1 affect dendritic cells?

Yes. Dendritic cell-associated signaling has been investigated in preclinical research.

Does Thymosin Alpha-1 affect Toll-like receptors?

Experimental studies have investigated relationships between Thymosin Alpha-1 and TLR-associated signaling pathways.

Is Thymosin Alpha-1 an immune booster?

It is more accurately described as an immunomodulatory peptide. Universal immune-enhancing effects have not been established.

Has Thymosin Alpha-1 been studied in humans?

Yes. Human clinical studies have evaluated thymalfasin in several immune-related conditions.

Has Thymosin Alpha-1 been studied for hepatitis B?

Yes. It has been investigated in chronic hepatitis B and marketed for this indication in certain jurisdictions.

Has Thymosin Alpha-1 been studied for hepatitis C?

Yes. Historical studies investigated thymalfasin in hepatitis C treatment settings.

Does Thymosin Alpha-1 improve survival in sepsis?

The large TESTS phase 3 trial did not demonstrate a statistically significant overall reduction in 28-day mortality.

Has Thymosin Alpha-1 been studied in cancer?

Yes. Clinical and preclinical research has investigated its immunomodulatory role in oncology.

Does Thymosin Alpha-1 cure cancer?

No. It is not established as a standalone cancer treatment.

Does Thymosin Alpha-1 prevent viral infections?

Universal preventive efficacy has not been established.

Is Thymosin Alpha-1 effective against COVID-19?

It is not established as a standard COVID-19 treatment.

Does Thymosin Alpha-1 reverse immune aging?

No. Reversal of human immunosenescence has not been established.

Is Thymosin Alpha-1 FDA-approved?

No. As of October 2026, it is not an FDA-approved medicine in the United States.

Is Thymosin Alpha-1 approved in other countries?

Pharmaceutical thymalfasin products have received marketing authorization in certain countries.

Is Thymosin Alpha-1 safe for human use?

Clinical safety data exist for specific pharmaceutical formulations and studied populations, but research-grade products are not established as suitable for human administration.

Is ICAME Pharmacy Thymosin Alpha-1 intended for human use?

No. It is intended strictly for laboratory research and development purposes.