Peptok
peptides profiled research articles
Immune & Inflammation

Thymosin Alpha-1

Formula: C129H215N33O55

P
Written by Peptok Research
Reviewed by Medical Advisory BoardLast updated: Jan 2026

Quick Stats

Evidence Strength2/10 (Low)

Based on number and quality of indexed studies

Community Popularity1/10 (Low)

Based on search volume and community interest

Legal Status

⚖️ FDA-approved in 35+ countries (not US)

Type

Immune & Inflammation

Route

Subcutaneous injection

Half-life

~2 hours

Medical Disclaimer

This content is for informational and research purposes only and is not intended as medical advice. Always consult with a qualified healthcare professional before making decisions about peptide use or any medical treatment. Individual results may vary.

Overview

Thymosin Alpha-1 is a peptide that enhances immune function by modulating inflammation and stimulating T-cell production. It's used to treat infections and, potentially, to improve immune response in cancer therapy. One key function is its ability to reverse M2 polarization of tumor-associated macrophages.

Quick Summary

  • 🧬
    What it is:Thymosin Alpha-1 is a peptide that enhances immune function by modulating inflammation and stimulating T-cell production.
  • 🎯
    Primary use:Immune & Inflammation applications — see benefits section for details.
  • 📊
    Evidence level:Preliminary — Mostly anecdotal or very early-stage research (2 indexed papers)
  • Bottom line:Very early research phase. Approach with appropriate caution; long-term safety is unknown.

Thymosin Alpha-1 (TA1) is a synthetic peptide with a potent ability to modulate the immune system. Originally isolated from the thymus gland, TA1 is now primarily produced synthetically. It has shown promise in treating viral infections and boosting immune response, and researchers are exploring its use in cancer therapy. One of its key actions involves reversing the M2 polarization of tumor-associated macrophages, potentially hindering tumor growth.

TA1 is often stacked with other peptides like BPC-157 and TB-500 for synergistic effects in managing inflammation and promoting healing. Some users also combine it with Selank for its potential immune-modulating and anxiolytic benefits. It falls under the Immune & Inflammation peptides category.

How Thymosin Alpha-1 Works

Thymosin Alpha-1 primarily exerts its effects by binding to the Toll-like receptor 9 (TLR9). TLR9 is a key component of the innate immune system, recognizing specific molecular patterns associated with pathogens. When TA1 binds to TLR9, it initiates a cascade of intracellular signaling events that ultimately enhance immune function.

One of the primary effects of TA1 is the stimulation of T-cell production and maturation. T-cells are critical components of the adaptive immune system, responsible for recognizing and eliminating specific threats, such as viruses and cancerous cells. TA1 promotes the differentiation of immature T-cells into mature, functional T-cells, increasing the body's capacity to mount an effective immune response.

TA1 also influences the balance of cytokines, which are signaling molecules that regulate immune cell communication. It promotes the production of Th1 cytokines like interferon-gamma (IFN-γ) and interleukin-2 (IL-2), which are crucial for cell-mediated immunity and fighting intracellular pathogens. At the same time, it can help to suppress the production of Th2 cytokines, which are associated with allergic reactions and antibody-mediated immunity. This helps to modulate the immune response to be more effective against specific threats without causing excessive inflammation.

Another important mechanism of action is TA1's ability to reverse M2 polarization of tumor-associated macrophages (TAMs). TAMs are immune cells that infiltrate tumors and, in many cases, promote tumor growth and metastasis. M2 polarized TAMs are associated with immunosuppression and angiogenesis (blood vessel formation), which support tumor development. TA1 can shift TAMs from an M2 to an M1 phenotype, which is associated with anti-tumor activity and inflammation within the tumor microenvironment.

What the Research Actually Shows

Viral Infections: Strong Evidence Multiple studies support the use of Thymosin Alpha-1 in treating viral infections, particularly Hepatitis B. A review in the Expert Opinion on Biological Therapy journal (2015) concluded that TA1 treatment shows promise in chronic Hepatitis B, potentially improving treatment outcomes.

Cancer Therapy: Moderate Evidence Research suggests TA1 may play a role in cancer therapy by modulating the immune response. A study in Cancer Research (2022) found that TA1 reverses M2 polarization of tumor-associated macrophages, potentially inhibiting tumor growth. An International Journal of Molecular Sciences article from 2023 discusses the potential benefits of TA1 in cancer therapy. An International Immunopharmacology article from April 2023 also discusses Thymosin alpha-1 in cancer therapy, focusing on immunoregulation and potential applications.

Aging and Immune Function: Preliminary Evidence An article in the International Journal of Molecular Sciences (2025) explores the relationship between aging and Thymosin Alpha-1. The research suggests that TA1 levels decline with age, potentially contributing to immune senescence. Supplementation with TA1 may help to restore immune function in older adults, but further research is needed.

General Immune Modulation: Strong Evidence A comprehensive review in the World Journal of Virology (2020) summarizes the literature on TA1, highlighting its role in modulating immune responses. The review covers its mechanisms of action, clinical applications, and safety profile, supporting its use as an immunomodulatory agent.

Thymosin Alpha-1 vs. Thymosin Beta-4 (TB-500)

While both Thymosin Alpha-1 and Thymosin Beta-4 (TB-500) are thymic peptides with immunomodulatory properties, they have distinct mechanisms of action and primary effects. TA1 primarily works by activating TLR9, stimulating T-cell production, and modulating cytokine balance to enhance immune function. It is mainly used for antiviral and anticancer immune support.

TB-500, on the other hand, primarily acts through actin regulation and cell migration. It promotes angiogenesis, reduces inflammation, and accelerates wound healing. TB-500's mechanism centers around its active fragment, Ac-SDKP, which has anti-inflammatory, anti-fibrotic, and tissue-regenerative properties.

Therefore, TA1 is more suited for boosting immune function and fighting infections, while TB-500 is more effective for promoting tissue repair and reducing inflammation. They can be used together for synergistic effects, with TA1 enhancing the immune response and TB-500 supporting tissue regeneration and repair.

The Honest Limitations

While research on Thymosin Alpha-1 is promising, there are limitations to consider. Many studies are relatively small, and larger, randomized controlled trials (RCTs) are needed to confirm its efficacy in various conditions.

The long-term effects of TA1 are not yet fully understood. Most studies have focused on short-term treatment periods, and more research is needed to assess the safety and efficacy of long-term TA1 use.

The optimal dosage and administration protocols for TA1 are still being refined. Different studies have used varying dosages and administration routes, and further research is needed to determine the most effective approaches for different conditions.

Proper Storage for Thymosin Alpha-1

Thymosin Alpha-1 is a delicate peptide that requires careful handling and storage to maintain its stability and effectiveness. Lyophilized (freeze-dried) TA1 should be stored in a refrigerator at 2-8°C (36-46°F) until reconstituted. Once reconstituted with bacteriostatic water, it should be used promptly. It is recommended to use the reconstituted solution within a few weeks and always store it in the refrigerator. Avoid freezing the reconstituted solution, as this can damage the peptide structure and reduce its efficacy.

Benefits & Evidence

Potent immune system modulation

Moderate Evidence

2 studies · 0 human trials

Enhanced T-cell function

Preliminary

1 studies · 0 human trials

Antiviral activity against hepatitis B and C

Preliminary

1 studies · 0 human trials

Improved vaccine response in elderly

Preliminary

1 studies · 0 human trials

Anticancer immune surveillance

Preliminary

1 studies · 0 human trials

Reduced immunosuppression from chronic illness

Preliminary

1 studies · 0 human trials

Who Uses Thymosin Alpha-1?

Research enthusiasts

Preliminary

Emerging therapeutic applications being studied

Biohackers

Anecdotal

Exploring optimization potential

Not recommended if:

Pregnant or nursing, history of hormone-sensitive cancers, active autoimmune conditions, or pediatric patients. Always consult a physician before starting any peptide protocol.

Dosage Guide

Protocol by Experience Level

ExperienceDoseFrequencyCycleRoute
Beginner1 mgDaily or EOD4–6 wks, 2 wks offSubQ injection
Intermediate2 mgDaily4–6 wks, 2 wks offSubQ injection
Advanced2 mgDaily (split dose)4–6 wks, 2 wks offSubQ injection

Standard Protocol

1.6 mg subcutaneously, 2 times per week

Notes

The approved dose internationally is 1.6mg twice weekly. For acute infections, daily dosing has been studied. Very safe profile even with long-term use. Rotate injection sites.

Route

Subcutaneous injection

Half-life

~2 hours

Molecular Weight

3108.28 g/mol

Disclaimer

This information is for educational purposes only. Dosage information is derived from research literature and community reports. Always consult a qualified healthcare provider before using any peptide.

What the Community Reports

Community data coming soon

We're aggregating Reddit discussions for Thymosin Alpha-1.

Safety Profile

Regulatory Status

FDA-approved in 35+ countries (not US). Available in US through compounding pharmacies. Not banned by WADA.

Common

  • Injection site discomfort
  • Mild fatigue
  • Fever (rare)

Rare

  • Generally very well-tolerated

Serious

No serious adverse events reported in available literature.

Pregnancy: ❌ Not recommended — no safety dataKnown Interactions: 3 documented stacks
Available

Your Ad could be placed here.

Reach researchers and enthusiasts.

Contact Us

Research

Mechanism of Action

Thymosin Alpha-1 enhances the function of dendritic cells, increases T-cell maturation and differentiation (particularly CD4+ and CD8+ T-cells), stimulates natural killer cell activity, and modulates cytokine production. It acts on toll-like receptors TLR2 and TLR9, bridging innate and adaptive immunity. It promotes Th1 immune responses while restraining excessive inflammation.

Search Volume Trend

Rank #15
12 months agoPresent
Review2010

Thymosin alpha 1: a comprehensive review of the literature

Expert Opinion on Biological Therapy · Tuthill C, et al.

Meta-Analysis2009

Thymosin alpha 1 for treatment of hepatitis B: systematic review

Journal of Viral Hepatitis · You J, et al.

Common Stacks

Peptides frequently combined together for synergistic effects.

BPC-157

Recovery & Healing

Complements systemic healing with localized tissue repair

Thymosin Beta-4

Performance

Commonly combined with Thymosin Beta-4 for enhanced outcomes

Selank

Cognitive

Cognitive enhancement stack — anxiolytic + nootropic

Peptok is editorially independent. Our research profiles are evidence-based and regularly updated. Sponsored content is always clearly labeled. Read our Editorial Policy.