Thymosin Alpha-1

Dosing from the Literature

Published for immune use: the Zadaxin label’s 1.6 mg under the skin twice a week for 6 to 12 months in hepatitis B, and 1.6 mg every 12 hours for 5 to 7 days in the sepsis trials. Not published: a US-approved dose, or a trial of any dose for general “immune support” in healthy people.

These are the doses on the Zadaxin label abroad and in the published trials, with their sources. They are not recommendations.

What It Is

Thymosin alpha-1 (Tα1) is a heat-stable, highly acidic peptide of 28 amino acids, isolated from calf thymus (thymosin fraction 5) and sequenced by Allan Goldstein’s group in 1977 (Goldstein et al., PNAS 1977; PMID 265536). In the body it is a cleavage product of a larger protein, prothymosin alpha, cut by an asparaginyl endopeptidase (Traub et al., Lab Invest 2006; PMID 16485008). Its N-terminus is acetylated; synthetic and recombinant acetylated Tα1 both weigh about 3,108 daltons (Liu et al., ScientificWorldJournal 2013; PMID 24288480).

The synthetic drug is thymalfasin, sold as ZADAXIN by SciClone Pharmaceuticals, which licensed the rights for the world outside the United States and Europe in the early 1990s (Tuthill, Ann N Y Acad Sci 2007; PMID 17947591). Each vial holds 1.6 mg of lyophilized thymalfasin with 50 mg of mannitol and a phosphate buffer, and is mixed with 1 mL of the supplied diluent before an injection under the skin (Zadaxin label). SciClone’s annual report for 2015 says ZADAXIN is approved in over 30 countries, mainly China and countries in the Pacific Rim, Latin America, Eastern Europe and the Middle East, principally for hepatitis B and as an immune system enhancer, with additional approvals in some countries for hepatitis C; China, its largest market, approved it for hepatitis B and as an immune enhancer (SciClone annual report, 2015). A 2009 review put the count at over 35 countries (Goldstein & Goldstein, Expert Opin Biol Ther 2009; PMID 19392576).

The FDA has never approved it. A double-blind phase 3 trial in hepatitis B did not confirm the benefit earlier trials reported (Mutchnick et al., 1999), and a 552-patient trial adding it to peginterferon and ribavirin for hepatitis C did not raise cure rates (Ciancio et al., 2012). In the US it holds orphan-drug designations for malignant melanoma, chronic hepatitis B and liver cancer (SciClone annual report, 2015). For compounding, FDA once placed it in Category 2 of its interim policies over concerns about immunogenicity, impurities and characterization; the nomination was withdrawn, so it sits on no 503A list, and FDA’s 503B nominations list puts it in Category 3 (FDA safety-risks page; FDA 503A and 503B lists).

Mechanism of Action

What has been shown comes from cell cultures and mice, plus immune markers measured in the human trials:

• Dendritic cells, through Toll-like receptors and MyD88 — In dendritic cells exposed to Aspergillus, Tα1 drove maturation and interleukin-12 production by fungus-exposed dendritic cells through the p38 MAPK / NF-κB pathway, signaling through MyD88-dependent Toll-like receptors; in mice given bone-marrow transplants it protected against aspergillosis (Romani et al., Blood 2004; PMID 14982877).
• TLR9, IDO and regulatory T cells — Tα1 signals through TLR9 and switched on indoleamine 2,3-dioxygenase (IDO) in mouse dendritic cells, which needed type I interferon signaling and led to interleukin-10 production and regulatory T cells: Th1 immunity together with tolerance (Romani et al., Blood 2006; PMID 16741252).
• Immune cell subsets — A 2016 review describes Tα1 acting through Toll-like receptors in myeloid and plasmacytoid dendritic cells and affecting several immune-cell subsets involved in immune suppression (King & Tuthill, Vitam Horm 2016; PMID 27450734).
• Markers moved in patients — In the ETASS sepsis trial, monocyte HLA-DR rose more on Tα1 than on control at days 3 and 7 (Wu et al., 2013). In a retrospective COVID-19 cohort, Tα1 was associated with lower PD-1 and Tim-3 on CD8+ T cells (Liu et al., 2020). Another cohort found no faster recovery of CD4+ or CD8+ counts (Wang et al., 2021).
• Serum levels — A review reports lower serum Tα1 than in healthy people in hepatitis B, psoriatic arthritis, multiple sclerosis and sepsis, and says basal levels and the best dose and schedule are still open questions (Pica et al., Expert Opin Biol Ther 2018; PMID 30063864).

What the Research Shows

Tα1 has been tested in people for decades, mostly in hepatitis, sepsis, vaccines and cancer. The pattern: small or open trials often report benefit, and the larger blinded ones mostly do not. The trials are laid out in Human Data.

• Hepatitis B — Positive in a 98-patient trial (Chien 1998), not confirmed in a 97-patient double-blind phase 3 (Mutchnick 1999). A 2026 Cochrane review of 10 randomized trials (1,349 people) could not say whether it reduces deaths or complications: the certainty was very low (Naing et al., 2026).
• Hepatitis C — Added to interferon it raised end-of-treatment responses (Sherman 1998), but added to peginterferon and ribavirin in 552 non-responders it did not raise cure rates (Ciancio 2012).
• Sepsis — ETASS (361 patients, single-blind) found 26.0% versus 35.0% deaths at 28 days, a borderline result (Wu 2013). The larger, double-blind TESTS (1,106 patients) found 23.4% versus 24.1%: no difference (Wu 2025). A 2025 meta-analysis found a benefit only when the smaller, lower-quality trials were included (Gu 2025).
• COVID-19 — Retrospective Chinese cohorts point both ways, from lower mortality (Liu 2020) to no difference after matching (Sun 2021) and worse recovery (Liu 2021). One small randomized pilot found faster CD4+ recovery but no significant difference in clinical recovery (Shehadeh 2023). Two meta-analyses disagree (Shang 2023; Soeroto 2023).
• Vaccines — Tested as an add-on to influenza vaccine in men 65 and over (Gravenstein 1989) and to an H1N1 vaccine in people on hemodialysis, where antibody responses were higher with Tα1 (Carraro 2012).
• Cancer — In 488 people with metastatic melanoma, adding Tα1 to dacarbazine gave more tumor responses; overall survival was 9.4 versus 6.6 months, not statistically significant (Maio 2010).
• Laboratory work — In mice with cystic fibrosis and in cells from people with the p.Phe508del mutation, Tα1 reduced inflammation and increased CFTR maturation, stability and activity (Romani et al., Nat Med 2017; PMID 28394330).

Human Data

Approvals abroad

• ZADAXIN in over 30 countries — Mainly China and countries in the Pacific Rim, Latin America, Eastern Europe and the Middle East; principally for hepatitis B and as an immune system enhancer, with hepatitis C approvals in some countries. In China it is approved for hepatitis B and as an immune enhancer and is in the health ministry’s liver-cancer treatment guidelines (SciClone annual report, 2015). The label reproduced on RxList lists chronic hepatitis B, chronic hepatitis C with interferon, and chemotherapy-induced immune depression in cancers including non-small-cell lung cancer, melanoma and liver cancer (Zadaxin label). A 2009 review says over 35 countries (Goldstein & Goldstein, 2009).
• Not approved by the FDA — A double-blind phase 3 trial in hepatitis B (below) did not confirm efficacy. SciClone holds US orphan-drug designations for malignant melanoma, chronic hepatitis B and liver cancer (SciClone annual report, 2015).

Hepatitis B

• Chien et al., Hepatology 1998 (PMID 9581695) — 98 patients randomized to 1.6 mg twice a week for 26 or 52 weeks, or no treatment. Eighteen months after entry, complete virological response (HBV DNA and HBeAg cleared) was 40.6% after 26 weeks and 26.5% after 52 weeks, versus 9.4% untreated; at the end of therapy the rates were similar. No significant side effects.
• Mutchnick et al., J Viral Hepat 1999 (PMID 10607256) — Multicentre phase 3, double-blind and placebo-controlled: 97 patients, 1.6 mg or placebo twice a week for 6 months. Complete response 14% versus 4% (P = 0.084); the authors wrote that the results “do not confirm observations of treatment efficacy reported in other clinical studies.”
• Iino et al., J Viral Hepat 2005 (PMID 15850471) — 316 Japanese patients randomized to 0.8 or 1.6 mg for 24 weeks, with no placebo group. Twelve months after treatment, 36.4% on 1.6 mg had normal ALT and 22.8% had cleared HBeAg; the two doses did about the same.
• Andreone et al., Hepatology 1996 (PMID 8855175) — 33 anti-HBe-positive patients, Tα1 versus interferon for 6 months: complete response 29.4% versus 43.8% at the end of treatment and 41.2% versus 25% six months later, neither difference significant.
• Lim et al., Antivir Ther 2006 (PMID 16640105) — 98 patients, Tα1 or placebo added to interferon for 24 weeks, double-blind: HBeAg loss 45.8% versus 28.0% (P = 0.067).
• Saruc et al., J Pharm Sci 2003 (PMID 12820143) — 52 HBeAg-negative patients assigned without randomization: sustained response 74% with Tα1 plus interferon, versus 40% on interferon and 53.3% on interferon plus lamivudine.
• Zhang et al., Virol J 2009 (PMID 19467157) — Meta-analysis of 8 trials (583 HBeAg-positive patients): lamivudine plus Tα1 beat lamivudine alone on HBeAg seroconversion (45.1% versus 15.2%), virological response (84.7% versus 74.9%) and ALT normalization (80.2% versus 68.8%).
• Naing et al., Cochrane 2026 (PMID 42713852) — 10 randomized trials, 1,349 people. Tα1 may reduce all-cause mortality (risk ratio 0.53, very low certainty) and serious adverse events (0.72, low certainty); the authors are “not sure” whether it reduces deaths or complications and found no ongoing trials.

Hepatitis C

• Sherman et al., Hepatology 1998 (PMID 9537454) — 109 patients, double-blind: Tα1 1.6 mg twice a week with interferon, interferon alone, or placebo. End-of-treatment biochemical response 37.1%, 16.2% and 2.7% (P = 0.04 for the combination versus interferon); sustained responses 14.2% and 8.1%.
• Ciancio et al., J Viral Hepat 2012 (PMID 22233415) — 552 people who had failed peginterferon and ribavirin, re-treated for 48 weeks with Tα1 or placebo added. Sustained viral response 12.7% versus 10.5% (P = 0.407); only among those who completed all 48 weeks was it higher (41.0% versus 26.3%). The authors: Tα1 “seems to play no role in the primary therapy of the disease.”
• Poo et al., Ann Hepatol 2008 (PMID 19034238) — Open-label, single arm: 40 Hispanic non-responders on Tα1 with peginterferon and ribavirin for 48 weeks; 21.1% sustained response per protocol.

Sepsis

• ETASS: Wu et al., Crit Care 2013 (PMID 23327199) — 361 patients with severe sepsis in six Chinese hospitals, single-blind. 28-day mortality 26.0% on Tα1 versus 35.0% on control (P = 0.062; log rank P = 0.049; relative risk 0.74, 95% CI 0.54 to 1.02). Monocyte HLA-DR improved more on Tα1. No serious drug-related adverse event.
• TESTS: Wu et al., BMJ 2025 (PMID 39814420) — Phase 3, double-blind and placebo-controlled, 22 Chinese centers, 1,106 adults with sepsis. 28-day mortality 23.4% versus 24.1% (hazard ratio 0.97, 95% CI 0.76 to 1.24; corrected after publication, PMID 40447307). No secondary or safety outcome differed. In prespecified subgroups, results differed by age (under 60: hazard ratio 1.67) and diabetes (0.58).
• Gu et al., Front Cell Infect Microbiol 2025 (PMID 40969554) — Meta-analysis of 11 randomized trials (1,927 patients): odds ratio 0.73 for 28-day mortality overall, but no significant benefit in the high-quality (0.82, 95% CI 0.65 to 1.03) or multicenter (0.86) trials, and the total sample was judged too small.

COVID-19

• Liu et al., Clin Infect Dis 2020 (PMID 32442287) — Retrospective, 76 severe patients in two Wuhan hospitals: mortality 11.1% on Tα1 versus 30.0% untreated (P = 0.044), with higher T-cell counts and lower PD-1 and Tim-3 on CD8+ T cells.
• Wu et al., Int Immunopharmacol 2020 (PMID 32795897) — Retrospective, 334 patients in eight centers, 1.6 mg once or twice a day for more than 5 days: lower adjusted 28-day mortality overall and in critical patients (hazard ratio 0.11), no difference at 60 days.
• Sun et al., Int Immunopharmacol 2021 (PMID 33208294) — Retrospective, 771 critically ill patients in 19 hospitals: 41.3% versus 60.6% died before matching, 51.0% versus 52.9% after propensity matching. No association with lower mortality.
• Liu et al., Front Immunol 2021 (PMID 34408744) — Five Hubei hospitals, 2,282 patients: after adjustment, Tα1 was associated with a higher non-recovery rate (odds ratio 1.5), most in the sicker patients.
• Wang et al., Front Immunol 2021 (PMID 34149679) — 275 patients in Shanghai: no faster recovery of CD4+ or CD8+ counts, and longer virus clearance, with Tα1.
• Huang et al., Front Med 2021 (PMID 33968969) — 1,388 non-severe patients: no difference in progression to severe disease; shorter viral shedding and hospital stay.
• Shehadeh et al., J Infect Dis 2023 (PMID 36056913) — Randomized, open-label pilot, 49 hospitalized patients with low oxygen and low lymphocytes: clinical recovery not significantly different; CD4+ counts rose faster in treated patients on low-flow oxygen.
• Meta-analyses — Nine studies, 5,352 patients: mortality risk ratio 1.03 (0.60 to 1.75); the authors do not support its use in hospitalized adults (Shang et al., 2023; PMID 36527881). Eight studies of moderate to critical patients: risk ratio 0.59 (0.37 to 0.93) with high heterogeneity, and a call for randomized trials (Soeroto et al., 2023; PMID 37845598).
• Dialysis patients, prevention (Tuthill et al., Int Immunopharmacol 2023; PMID 36881981) — 194 patients randomized to 1.6 mg twice a week for 8 weeks or no treatment; a preliminary report counted 3 deaths versus 7, with the analysis still to come.

Vaccines and cancer

• Gravenstein et al., J Am Geriatr Soc 1989 (PMID 2642497) — 90 men aged 65 to 99, double-blind: Tα1 900 µg/m² twice a week for 8 doses, or placebo, with the 1986 influenza vaccine; no toxicity. SciClone’s annual report says trials in the elderly lowered influenza incidence from 19% to 6% (SciClone annual report, 2015).
• Carraro et al., Vaccine 2012 (PMID 22178096) — Pilot in people on hemodialysis given an adjuvanted H1N1 vaccine alone or with Tα1 3.2 or 6.4 mg: both Tα1 groups had higher antibody titers at day 21 and met the European criteria; no adverse event was related to Tα1.
• Maio et al., J Clin Oncol 2010 (PMID 20194853) — 488 people with metastatic melanoma in five arms. Tumor responses: 10 and 12 in two Tα1 3.2 mg arms versus 4 on control; median overall survival 9.4 versus 6.6 months (hazard ratio 0.80, P = 0.08). No added toxicity.

The evidence meter on the thymosin alpha-1 card reads “Controlled trials”: randomized, controlled trials of it for immune use have been published. None led to an FDA approval.

Reconstitution & Storage

Zadaxin comes as a 1.6 mg lyophilized vial with its own diluent. The label says to reconstitute it with 1.0 mL of the diluent immediately before use and to store it at 2–8°C (Zadaxin label); the sepsis trials mixed each vial the same way, giving 1.6 mg/mL (Wu et al., 2013; Wu et al., 2025). No document read for this page gives the contents or storage of research-chemical vials; the calculator does the arithmetic for any vial.

• Route — Subcutaneous in the label and in every trial on this page.
• Arithmetic only — The table converts the label’s vial into syringe units (100 units = 1 mL). It is not a recommendation.

→ Calculator — vial-to-syringe math

Side Effects & Risks

• On the label — Local discomfort at the injection site, and rare erythema, transient muscle atrophy, joint pain with hand swelling, and rash (Zadaxin label).
• In the trials — No serious drug-related adverse event in ETASS (Wu et al., 2013); no safety outcome differed from placebo in TESTS (Wu et al., 2025); no difference in adverse events in the 552-patient hepatitis C trial (Ciancio et al., 2012); no added toxicity with dacarbazine in melanoma (Maio et al., 2010). Adverse reactions in the Japanese hepatitis B trial were mild, mostly liver-enzyme fluctuations (Iino et al., 2005); local discomfort at the injection site was the only side effect in the 1996 hepatitis B trial (Andreone et al., 1996).
• A signal to note — In TESTS, people under 60 fared worse on Tα1 than on placebo in a prespecified subgroup (hazard ratio 1.67), and people with diabetes fared better (0.58); the trial reports these as possible differences, not findings (Wu et al., 2025). In one COVID-19 cohort, Tα1 was associated with more non-recovery (Liu et al., 2021).
• Not tested — No document read for this page tested Tα1 in pregnancy, in people with active autoimmune disease, or with transplant immunosuppression.
• WADA — Not named on WADA’s 2026 Prohibited List, which names thymosin-β4 and TB-500, a different peptide (WADA 2026).
• Research-chemical supply — FDA’s concerns above apply to compounded product; no document read for this page tested any research-chemical thymosin alpha-1.

Bloodwork & Monitoring

What the trials measured, by use. These describe the studies; they are not a monitoring plan:

• Hepatitis B — HBV DNA, HBeAg, ALT and liver histology (Chien et al., 1998; Mutchnick et al., 1999; Iino et al., 2005).
• Hepatitis C — ALT, HCV RNA and histology (Sherman et al., 1998); sustained viral response (Ciancio et al., 2012).
• Sepsis — SOFA score and monocyte HLA-DR on days 0, 3 and 7 (Wu et al., 2013).
• COVID-19 — CD4+ and CD8+ T-cell counts, and PD-1 and Tim-3 on CD8+ T cells (Liu et al., 2020; Wang et al., 2021; Shehadeh et al., 2023).
• Vaccines — Antibody titers after vaccination (Gravenstein et al., 1989; Carraro et al., 2012), with hematology and blood chemistry for safety in the hemodialysis pilot.
• Serum Tα1 — A review argues for knowing a patient’s baseline serum Tα1 before treatment, and says its physiological basal level is still an open question (Pica et al., 2018).

Commonly Stacked With

In the trials, thymosin alpha-1 was given alongside a standard treatment, not alone. No study has tested it together with other research peptides.

Stacking this? Read the receipt →

→ Calculator — vial-to-syringe math

Legal Status

Related Compounds

Peptides that show up alongside Thymosin Alpha-1:

Next Steps

References

1. Goldstein AL, Low TL, McAdoo M, McClure J, Thurman GB, Rossio J, Lai CY, Chang D, Wang SS, Harvey C, Ramel AH, Meienhofer J. Thymosin alpha1: isolation and sequence analysis of an immunologically active thymic polypeptide. Proc Natl Acad Sci U S A. 1977;74(2):725-9. PMID: 265536.
2. Traub F, Jost M, Hess R, Schorn K, Menzel C, Budde P, Schulz-Knappe P, Lamping N, Pich A, Kreipe H, Tammen H. Peptidomic analysis of breast cancer reveals a putative surrogate marker for estrogen receptor-negative carcinomas. Lab Invest. 2006;86(3):246-53. PMID: 16485008.
3. Liu B, Gong X, Chang S, Sun P, Wu J. Generation of mature Nα-terminal acetylated thymosin α 1 by cleavage of recombinant prothymosin α. ScientificWorldJournal. 2013;2013:387282. PMID: 24288480.
4. Tuthill C. Issues in pharmaceutical development of thymosin alpha1 from preclinical studies through marketing. Ann N Y Acad Sci. 2007;1112:351-6. PMID: 17947591.
5. Goldstein AL, Goldstein AL. From lab to bedside: emerging clinical applications of thymosin alpha 1. Expert Opin Biol Ther. 2009;9(5):593-608. PMID: 19392576.
6. SciClone Pharmaceuticals, Inc. Annual Report on Form 10-K for the year ended December 31, 2015 (filed March 11, 2016). U.S. Securities and Exchange Commission, EDGAR: sec.gov/Archives/edgar/data/880771/000088077116000135/scln-20151231x10k.htm. Read September 30, 2026. (ZADAXIN approvals, uses and US orphan designations.)
7. ZADAXIN (thymalfasin) prescribing information, as reproduced on RxList (page updated June 28, 2021): rxlist.com/zadaxin-drug.htm. Read September 30, 2026. (Vial contents, labeled uses, dose, reconstitution, storage, adverse reactions.)
8. U.S. Food and Drug Administration. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks (content current as of April 22, 2026): fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks. Read September 30, 2026. (Thymosin alpha-1 under “Bulk drug substances nominated but withdrawn”.)
9. U.S. Food and Drug Administration. Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act (updated May 14, 2026): fda.gov/media/94155/download. Read September 30, 2026.
10. U.S. Food and Drug Administration. Bulk Drug Substances Nominated for Use in Compounding Under Section 503B of the Federal Food, Drug, and Cosmetic Act (updated March 21, 2025): fda.gov/media/94164/download. Read September 30, 2026. (Thymosin alpha-1 in Category 3.)
11. World Anti-Doping Agency. The 2026 Prohibited List (September 2025): wada-ama.org/sites/default/files/2025-09/2026list_en_final_clean_september_2025.pdf. Read September 30, 2026.
12. Romani L, Bistoni F, Gaziano R, Bozza S, Montagnoli C, Perruccio K, Pitzurra L, Bellocchio S, Velardi A, Rasi G, Di Francesco P, Garaci E. Thymosin alpha 1 activates dendritic cells for antifungal Th1 resistance through toll-like receptor signaling. Blood. 2004;103(11):4232-9. PMID: 14982877.
13. Romani L, Bistoni F, Perruccio K, Montagnoli C, Gaziano R, Bozza S, et al. Thymosin alpha1 activates dendritic cell tryptophan catabolism and establishes a regulatory environment for balance of inflammation and tolerance. Blood. 2006;108(7):2265-74. PMID: 16741252.
14. King R, Tuthill C. Immune Modulation with Thymosin Alpha 1 Treatment. Vitam Horm. 2016;102:151-78. PMID: 27450734.
15. Pica F, Gaziano R, Casalinuovo IA, Moroni G, Buè C, Limongi D, D'Agostini C, Tomino C, Perricone R, Palamara AT, Sinibaldi Vallebona P, Garaci E. Serum thymosin alpha 1 levels in normal and pathological conditions. Expert Opin Biol Ther. 2018;18(sup1):13-21. PMID: 30063864.
16. Chien RN, Liaw YF, Chen TC, Yeh CT, Sheen IS. Efficacy of thymosin alpha1 in patients with chronic hepatitis B: a randomized, controlled trial. Hepatology. 1998;27(5):1383-7. PMID: 9581695.
17. Mutchnick MG, Lindsay KL, Schiff ER, Cummings GD, Appelman HD, Peleman RR, Silva M, Roach KC, Simmons F, Milstein S, Gordon SC, Ehrinpreis MN. Thymosin alpha1 treatment of chronic hepatitis B: results of a phase III multicentre, randomized, double-blind and placebo-controlled study. J Viral Hepat. 1999;6(5):397-403. PMID: 10607256.
18. Iino S, Toyota J, Kumada H, Kiyosawa K, Kakumu S, Sata M, Suzuki H, Martins EB. The efficacy and safety of thymosin alpha-1 in Japanese patients with chronic hepatitis B; results from a randomized clinical trial. J Viral Hepat. 2005;12(3):300-6. PMID: 15850471.
19. Andreone P, Cursaro C, Gramenzi A, Zavagliz C, Rezakovic I, Altomare E, Severini R, Franzone JS, Albano O, Ideo G, Bernardi M, Gasbarrini G. A randomized controlled trial of thymosin-alpha1 versus interferon alfa treatment in patients with hepatitis B e antigen antibody--and hepatitis B virus DNA--positive chronic hepatitis B. Hepatology. 1996;24(4):774-7. PMID: 8855175.
20. Lim SG, Wai CT, Lee YM, Dan YY, Sutedja DS, Wee A, et al. A randomized, placebo-controlled trial of thymosin-alpha1 and lymphoblastoid interferon for HBeAg-positive chronic hepatitis B. Antivir Ther. 2006;11(2):245-53. PMID: 16640105.
21. Saruc M, Ozden N, Turkel N, Ayhan S, Hock LM, Tuzcuoglu I, Yuceyar H. Long-term outcomes of thymosin-alpha 1 and interferon alpha-2b combination therapy in patients with hepatitis B e antigen (HBeAg) negative chronic hepatitis B. J Pharm Sci. 2003;92(7):1386-95. PMID: 12820143.
22. Zhang YY, Chen EQ, Yang J, Duan YR, Tang H. Treatment with lamivudine versus lamivudine and thymosin alpha-1 for e antigen-positive chronic hepatitis B patients: a meta-analysis. Virol J. 2009;6:63. PMID: 19467157.
23. Naing C, Ni H, Aung HH, Aye SN, Nikolova D, Poovorawan Y, Pavlov C. Thymosin-ɑ1 for people with chronic hepatitis B. Cochrane Database Syst Rev. 2026;9(9):CD014610. PMID: 42713852.
24. Sherman KE, Sjogren M, Creager RL, Damiano MA, Freeman S, Lewey S, Davis D, Root S, Weber FL, Ishak KG, Goodman ZD. Combination therapy with thymosin alpha1 and interferon for the treatment of chronic hepatitis C infection: a randomized, placebo-controlled double-blind trial. Hepatology. 1998;27(4):1128-35. PMID: 9537454.
25. Ciancio A, Andreone P, Kaiser S, Mangia A, Milella M, Solà R, Pol S, Tsianos E, De Rosa A, Camerini R, McBeath R, Rizzetto M. Thymosin alpha-1 with peginterferon alfa-2a/ribavirin for chronic hepatitis C not responsive to IFN/ribavirin: an adjuvant role?. J Viral Hepat. 2012;19 Suppl 1:52-9. PMID: 22233415.
26. Poo JL, Sánchez Avila F, Kershenobich D, García Samper X, Torress-Ibarra R, Góngora J, Cano C, Parada M, Uribe M. Efficacy of triple therapy with thymalfasin, peginterferon alpha-2a, and ribavirin for the treatment of hispanic chronic HCV nonresponders. Ann Hepatol. 2008;7(4):369-75. PMID: 19034238.
27. Wu J, Zhou L, Liu J, Ma G, Kou Q, He Z, et al. The efficacy of thymosin alpha 1 for severe sepsis (ETASS): a multicenter, single-blind, randomized and controlled trial. Crit Care. 2013;17(1):R8. PMID: 23327199.
28. Wu J, Pei F, Zhou L, Li W, Sun R, Li Y, et al; TESTS study collaborator group. The efficacy and safety of thymosin α1 for sepsis (TESTS): multicentre, double blinded, randomised, placebo controlled, phase 3 trial. BMJ. 2025;388:e082583. PMID: 39814420.
29. Correction: The efficacy and safety of thymosin α1 for sepsis (TESTS): multicentre, double blinded, randomised, placebo controlled, phase 3 trial. BMJ. 2025;389:r1098. PMID: 40447307. DOI: 10.1136/bmj.r1098.
30. Gu B, Zhou Y, Nie Y, Wang L, Liang L, Liao Z, Wen J, Guan X, Chen M, Wu J, Pei F. Efficacy of thymosin α1 for sepsis: a systematic review and meta-analysis of randomized controlled trials. Front Cell Infect Microbiol. 2025;15:1673959. PMID: 40969554.
31. Liu Y, Pan Y, Hu Z, Wu M, Wang C, Feng Z, et al. 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;71(16):2150-2157. PMID: 32442287.
32. Wu M, Ji JJ, Zhong L, Shao ZY, Xie QF, Liu ZY, Wang CL, Su L, Feng YW, Liu ZF, Yao YM. Thymosin α1 therapy in critically ill patients with COVID-19: A multicenter retrospective cohort study. Int Immunopharmacol. 2020;88:106873. PMID: 32795897.
33. Sun Q, Xie J, Zheng R, Li X, Chen H, Tong Z, Du B, Qiu H, Yang Y. The effect of thymosin α1 on mortality of critical COVID-19 patients: A multicenter retrospective study. Int Immunopharmacol. 2021;90:107143. PMID: 33208294.
34. Liu J, Shen Y, Wen Z, Xu Q, Wu Z, Feng H, et al. Efficacy of Thymosin Alpha 1 in the Treatment of COVID-19: A Multicenter Cohort Study. Front Immunol. 2021;12:673693. PMID: 34408744.
35. Wang Z, Chen J, Zhu C, Liu L, Qi T, Shen Y, Zhang Y, Xu L, Li T, Qian Z, Steinhart CR, Lu H. Thymosin Alpha-1 Has no Beneficial Effect on Restoring CD4+ and CD8+ T Lymphocyte Counts in COVID-19 Patients. Front Immunol. 2021;12:568789. PMID: 34149679.
36. Huang C, Fei L, Xu W, Li W, Xie X, Li Q, Chen L. Efficacy Evaluation of Thymosin Alpha 1 in Non-severe Patients With COVID-19: A Retrospective Cohort Study Based on Propensity Score Matching. Front Med (Lausanne). 2021;8:664776. PMID: 33968969.
37. Shehadeh F, Benitez G, Mylona EK, Tran QL, Tsikala-Vafea M, Atalla E, Kaczynski M, Mylonakis E. A Pilot Trial of Thymalfasin (Thymosin-α-1) to Treat Hospitalized Patients With Hypoxemia and Lymphocytopenia Due to Coronavirus Disease 2019 Infection. J Infect Dis. 2023;227(2):226-235. PMID: 36056913.
38. Shang W, Zhang B, Ren Y, Wang W, Zhou D, Li Y. Thymosin alpha1 use in adult COVID-19 patients: A systematic review and meta-analysis on clinical outcomes. Int Immunopharmacol. 2023;114:109584. PMID: 36527881.
39. Soeroto AY, Suryadinata H, Yanto TA, Hariyanto TI. The efficacy of thymosin alpha-1 therapy in moderate to critical COVID-19 patients: a systematic review, meta-analysis, and meta-regression. Inflammopharmacology. 2023;31(6):3317-3325. PMID: 37845598.
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