Thymosin Alpha-1 (5mg & 10mg)


Size: 5mg & 10mg
Contents: Thymosin Alpha-1
Form: Lyophilized powder
Purity: >99%

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Discount per Quantity

5 - 85%$72.20$133.00
9 +10%$68.40$126.00
SKU: P-THYMOSA1-5-10 Category: Tag:


Thymosin Alpha-1 Peptide

Thymosin Alpha-1 peptide, also known as Thymosin Alpha, TA1, or T α 1, is a fragment of a protein molecule that has been widely studied for its potential implications with the immune system. Researchers have hypothesized that it contributes to the production of T-cells to mitigate and alleviate infection and bacterial spread. (1)

Thymosin Alpha-1 is a naturally occurring polypeptide that is considered by researchers to potentially restore and enhance immune functions (3). Thymosin Alpha-1 is considered to be one of the polypeptides found in Thymosin Fraction 5, which is a crude extract of the thymus gland (4).

Since its discovery, a synthetically developed form of Thymosin Alpha-1 has also been studied, researchers refer to the peptide as Thymalfasin (3). Thymalfasin is composed of 28 amino acids, similar to the naturally occurring Thymosin Alpha-1, and is derived from a longer polypeptide precursor composed of 113 amino acids, known as Prothymosin Alpha (4).



The main aim of initial research into Thymosin Alpha-1 (5) was to understand and examine the immunomodulating potential of the peptide. Studies have suggested that the peptide may increase the concentration of the major histocompatibility complex (MHC) class I and cytokine production, which may possibly lead to increased immune responses.

Researchers speculate that Thymosin Alpha-1 may stimulate possible action by targeting the T-helper cells and cytotoxic T-cell populations (4). Thymosin Alpha-1 may possibly induce differentiation of the T-cells (thymocytes) and the terminal differentiation of the blood lymphocytes. Scientists posit that it may elevate the production of the natural killer cells and potentially stimulate cytokine mediated inflammation (3,4). Furthermore, the peptide has been studied for its potential to enhance efficiency of macrophages and functions as the modulator of the alpha thrombin activity (4).

Research and Clinical Studies

Thymosin Alpha-1 Peptide and Immune System

In this clinical study (6), 11 test subjects with different immune system dysfunctions were evaluated for the levels of their natural killer (NK) and lymphokine activated killer cells (LAK) present in their system. It was noted that the immunodeficient subjects demonstrated the mean LAK-cell activity of approximately 65% as compared to the control subjects. Upon presenting Thymosin Alpha-1 to the test subjects, researchers observed that it did not significantly improve the levels of NK or LAK cells. Only 3 test subjects were reported to exhibit improved LAK-cell activity by up to 30% whereas others were not significantly impacted.


Thymosin Alpha-1 Peptide and Hepatitis

Clinical trials were conducted in test subjects with liver complications, with some exhibiting Hepatitis B & C. Thymosin Alpha-1 was presented to the subjects to explore its potential mechanism of action on these complications (3). For subjects exhibiting Hepatitis B, it was reported by the research team that when these subjects were presented with Thymosin Alpha-1 twice a week for the duration of the study, the reported virological response rate of the subjects appeared increased by 40.6%. For Hepatitis C, subjects reportedly exhibited improved results when Thymosin Alpha-1 peptide was present in combination with interferon alpha compounds.


Thymosin Alpha-1 Peptide and Sepsis

In this 2015 study (7), a meta-analysis was conducted where all the relevant clinical trials prior to 2014 were analyzed to understand the possible mechanism of Thymosin Alpha-1 in relation to the sepsis reaction. In this study, 12 controlled trials were evaluated in total. Based on the extracted data and assessment, it was observed by the research analysts that there was a reported significant decline in mortality rate amongst test subjects following introduction to Thymosin Alpha-1. However, all these studies were conducted on an exceedingly small pool of test subjects.


Thymosin Alpha-1 Research with HIV

This study (8) consisted of a randomized phase II open-label clinical trial on 20 clinically stable test subjects. These patients were already undergoing highly active antiretroviral (HAART), alongside which Thymosin Alpha-1 peptide was presented to monitor the impact of the combination. Thymosin Alpha-1 was presented for two times in a week in 13 subjects. The remaining 7 subjects were given placebo. Every 2 weeks, the cell counts of CD4/CD8 cells, CD45 cells and signal joint T-cell receptor circles (sjTREC) levels were monitored. After 12 weeks, it was reported by the researchers that there were no apparent significant changes in the levels of CD4, CD and CD45 levels in both the peptide or the placebo group. However, the sjTREC levels reportedly increased in the subjects presented with the peptide. These elevated levels of sjTREC might potentially stimulate immune responses.

Thymosin Alpha-1 and Tumor Growth

In this study (9), the levels of the reactive oxygen species (ROS) were monitored in test models after the presentation of Thymosin Alpha-1.  During this study, Thymosin Alpha-1 was presented in mice with liver carcinoma. Both the leukomonocytes and HepG2 cells, given the peptide, were isolated from the mouse spleens, for the purpose of this study. Upon analysis, it was observed by the researchers that the ROS level appeared to be significantly higher in the isolated leuko-monocytes,  whereas it was apparently lower in the HepG2 cells. Also, the peptide appeared to possibly increase the levels of the leukomonocytes, whereas it may have delayed the cell cycle for HepG2 cells and thereby reduced their levels in the system.

Thymosin Alpha-1 peptide is available for research and laboratory purposes only. Please review our  Terms and Conditions before ordering.



1. Immunodeficiency, British Society for Immunology. Published March 2017.

2. Primary Immune Deficiency Diseases.

3. Dominari A, Hathaway Iii D, Pandav K, Matos W, Biswas S, Reddy G, Thevuthasan S, Khan MA, Mathew A, Makkar SS, Zaidi M, Fahem MMM, Beas R, Castaneda V, Paul T, Halpern J, Baralt D. Thymosin alpha 1: A comprehensive review of the literature. World J Virol. 2020 Dec 15;9(5):67-78. doi: 10.5501/wjv.v9.i5.67. PMID: 33362999; PMCID: PMC7747025.

4. National Center for Biotechnology Information. “PubChem Compound Summary for CID 16130571, Thymalfasin” PubChem,

5. Garaci E. Thymosin alpha1: a historical overview. Ann N Y Acad Sci. 2007 Sep;1112:14-20. doi: 10.1196/annals.1415.039. Epub 2007 Jun 13. PMID: 17567941.

6. Eckert K, Schmitt M, Garbin F, Wahn U, Maurer HR. Thymosin alpha 1 effects, in vitro, on lymphokine-activated killer cells from patients with primary immunodeficiencies: preliminary results. Int J Immunopharmacol. 1994 Dec;16(12):1019-25. doi: 10.1016/0192-0561(94)90081-7. PMID: 7705963.

7. Li C, Bo L, Liu Q, Jin F. Thymosin alpha1 based immunomodulatory therapy for sepsis: a systematic review and meta-analysis. Int J Infect Dis. 2015 Apr;33:90-6. doi: 10.1016/j.ijid.2014.12.032. Epub 2014 Dec 19. PMID: 25532482.

8. Chadwick D, Pido-Lopez J, Pires A, Imami N, Gotch F, Villacian JS, Ravindran S, Paton NI. A pilot study of the safety and efficacy of thymosin alpha 1 in augmenting immune reconstitution in HIV-infected patients with low CD4 counts taking highly active antiretroviral therapy. Clin Exp Immunol. 2003 Dec;134(3):477-81. doi: 10.1111/j.1365-2249.2003.02331.x. PMID: 14632754; PMCID: PMC1808897.

9. Qin Y, Chen FD, Zhou L, Gong XG, Han QF. Proliferative and anti-proliferative effects of thymosin alpha1 on cells are associated with manipulation of cellular ROS levels. Chem Biol Interact. 2009 Aug 14;180(3):383-8. doi: 10.1016/j.cbi.2009.05.006. Epub 2009 May 12. PMID: 19442654.

10. Panatto D, Amicizia D, Lai PL, Camerini R, De Rosa A, Gasparini R. Utility of thymosin alpha-1 (Zadaxin) as a co-adjuvant in influenza vaccines: a review. J Prev Med Hyg. 2011 Sep;52(3):111-5. PMID: 22010537.

11. Liu Y, Pan Y, Hu Z, Wu M, Wang C, Feng Z, Mao C, Tan Y, Liu Y, Chen L, Li M, Wang G, Yuan Z, Diao B, Wu Y, Chen Y. Thymosin Alpha 1 Reduces the Mortality of Severe Coronavirus Disease 2019 by Restoration of Lymphocytopenia and Reversion of Exhausted T Cells. Clin Infect Dis. 2020 Nov 19;71(16):2150-2157. doi: 10.1093/cid/ciaa630. PMID: 32442287; PMCID: PMC7314217.

12. Zadaxin (Thymalfasin): Uses, Dosage, Side Effects, Interactions, Warning [Internet]. RxList. 2009. Available from:

NOTE: These products are intended for laboratory research use only. Thymosin Alpha-1 for sale is not intended for personal use. Please review and adhere to our Terms and Conditions before ordering.

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