{ "schemaVersion": "2.1", "datasetVersion": "2026-09-11.1", "generatedAt": "2026-09-11", "reviewStatus": "Editorial source review is complete. This edition has not been independently medically reviewed.", "editorialBoundary": "Source-checked educational summaries. Topics require evidence and editorial review. This dataset is not a personal treatment plan.", "citation": "When you cite a record, include The Peptide Field, its canonicalPath, this dataset version, and every source used for the claim.", "reuse": "This endpoint grants no additional reuse license. Keep the verdict, scope, evidence basis, review date, and source links together. Do not present a record as medical advice or medical review.", "changeLogPath": "/corrections#correction-ledger", "contactPath": "/corrections", "dataset": "peptide-evidence-checker-record", "canonicalPath": "/peptides/thymosin-alpha-1", "canonicalUrl": "https://thepeptidefield.com/peptides/thymosin-alpha-1", "record": { "slug": "thymosin-alpha-1", "name": "Thymosin alpha-1", "aliases": [ "TA1", "Ta1", "Tα1", "Thymalfasin" ], "className": "Immune-signaling peptide", "family": "Thymic peptides", "sequenceLabel": "28 amino acids · small chemical cap on one end", "tier": "Emerging", "evidenceContext": "Investigational human outcomes", "statusLine": "No FDA-approved thymosin alpha-1 product was identified in the United States as reviewed August 30, 2026", "productContext": "FDA treats the free base and its acetate salt as different chemical forms. FDA's 2024 review described Zadaxin as a finished medicine with narrow approval outside the United States. The ingredient name alone does not identify that product. No FDA-approved U.S. product was found.", "approvedProducts": [], "productRecords": [], "indications": [ "Human research in sepsis and other immune-related conditions" ], "profile": { "humanOutcomes": { "level": "Moderate", "note": "A large randomized sepsis study found no clear drop in 28-day deaths. FDA found that the wider disease evidence did not establish a benefit." }, "humanPharmacology": { "level": "Moderate", "note": "Studies in people measured how it moved through the body and changed blood tests tied to the immune system. These findings do not establish a general health benefit." }, "safetyKnowledge": { "level": "Limited", "note": "The large sepsis study found no clear safety difference, but FDA says important safety questions remain for compounded products." }, "productCertainty": { "level": "Limited", "note": "Study material and Zadaxin do not show what is in an online or compounded product." } }, "oneLine": "A 28-amino-acid peptide studied in people. A large sepsis trial did not show fewer deaths, and no FDA-approved U.S. product was identified.", "reviewedAt": "August 30, 2026", "reviewedAtISO": "2026-08-30", "reviewHistory": [ { "date": "2026-08-30", "note": "Initial brief reviewed FDA identity and compounding records, randomized human trials, corrected sepsis results, and the 2026 World Anti-Doping Agency list." } ], "whatItIs": "Thymosin alpha-1 is a peptide with 28 amino acids. It has a small chemical group, called an acetyl group, on one end. Thymalfasin is the lab-made form of the same peptide. It is not thymosin beta-4, and it is not TB-500. Zadaxin is a finished medicine, not another name for every TA1 product.", "whatWeKnow": "Sepsis is a dangerous body response to infection. The TESTS study assigned 1,106 adults with sepsis at 22 centers in China to thymosin alpha-1 or placebo by chance. A placebo looks like the study product but has no active ingredient. In the corrected analysis, 23.4% of the thymosin alpha-1 group and 24.1% of the placebo group died within 28 days. This was not a clear difference. Other randomized studies tested severe pancreas inflammation, viral liver disease, and earlier sepsis groups. Their results did not establish a broad treatment benefit.", "whatWeDoNotKnow": "FDA reviewed proposed uses that included viral liver disease, cancer, sepsis, COVID-19, vaccine response, lung disease, and other conditions. FDA found too little reliable evidence to show that it worked for the uses it reviewed. The records do not show a general “immune boost,” infection prevention, long-COVID benefit, or anti-aging effect. They also do not show that an online or compounded product matches study material.", "antiDoping": "The reviewed 2026 World Anti-Doping Agency list does not name thymosin alpha-1. It does name thymosin beta-4 and TB-500, which are different substances.", "antiDopingReview": { "status": "No prohibition identified", "detail": "Thymosin alpha-1 is not named in the reviewed 2026 WADA list. Thymosin beta-4 and TB-500 are different substances and are named. This is not personal clearance. Athletes must check the current list and their sport rules.", "sourceUrl": "https://www.wada-ama.org/sites/default/files/2025-09/2026list_en_final_clean_september_2025.pdf", "reviewedAtISO": "2026-08-30" }, "safetyBoundary": "FDA says compounded thymosin alpha-1 may cause unwanted immune reactions. FDA also flags impurities and problems with confirming the active ingredient. The available data cannot define every risk. This guide gives no dosing, injection, sourcing, or treatment instructions.", "relatedSlugs": [ "tb-500", "kisspeptin-10", "bpc-157" ], "claims": [ { "claim": "“Thymosin alpha-1 has been studied in randomized human trials.”", "verdict": "Supported with scope", "explanation": "Yes. Randomized studies tested thymosin alpha-1 in people with specific illnesses. This only means human trials exist. It does not mean that they showed a benefit.", "category": "Clinical outcomes", "evidenceBasis": "Randomized human outcomes", "scope": "The exact study products and groups of people with each illness. A result from one illness does not transfer to another.", "sourceUrls": [ "https://www.fda.gov/media/183820/download", "https://www.bmj.com/content/388/bmj-2024-082583" ] }, { "claim": "“Thymosin alpha-1 reduced 28-day deaths in the large TESTS sepsis trial.”", "verdict": "Misleading", "explanation": "The corrected result was 23.4% with thymosin alpha-1 and 24.1% with placebo. The study found no clear difference in 28-day deaths.", "category": "Clinical outcomes", "evidenceBasis": "Randomized human outcomes", "scope": "The TESTS study randomized 1,106 adults with sepsis at 22 centers in China. The corrected analysis applies only to this study and outcome.", "sourceUrls": [ "https://www.bmj.com/content/388/bmj-2024-082583", "https://www.bmj.com/content/389/bmj.r1098" ] }, { "claim": "“Thymosin alpha-1 is FDA-approved in the United States.”", "verdict": "Misleading", "explanation": "FDA says no approved U.S. drug contains thymosin alpha-1 free base or its acetate salt. Foreign product status does not create U.S. approval.", "category": "Approval and status", "evidenceBasis": "Regulatory or product record", "scope": "United States regulatory status as reviewed August 30, 2026.", "sourceUrls": [ "https://www.fda.gov/media/183820/download", "https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks", "https://www.fda.gov/drugs/development-approval-process-drugs/drug-approvals-and-databases" ] }, { "claim": "“Every product sold as thymosin alpha-1 is equivalent to Zadaxin.”", "verdict": "Misleading", "explanation": "FDA's 2024 review describes Zadaxin as a finished medicine with narrow foreign approval. It is not the same as an ingredient name, a compounded product, or an online product.", "category": "Product equivalence", "evidenceBasis": "Regulatory or product record", "scope": "The exact product, ingredient form, way it was made, and country status all matter.", "sourceUrls": [ "https://www.fda.gov/media/183820/download" ] } ], "sources": [ { "label": "FDA identity overview for thymosin alpha-1", "publisher": "U.S. Food and Drug Administration", "url": "https://www.fda.gov/media/183645/download", "kind": "FDA review", "year": 2024, "accessedAt": "2026-08-30" }, { "label": "FDA review of the separate thymosin beta-4 fragment called TB-500", "publisher": "U.S. Food and Drug Administration", "url": "https://www.fda.gov/media/193349/download", "kind": "FDA review", "year": 2025, "accessedAt": "2026-08-30" }, { "label": "FDA evaluation of thymosin alpha-1 for pharmacy compounding", "publisher": "U.S. Food and Drug Administration", "url": "https://www.fda.gov/media/183820/download", "kind": "FDA review", "year": 2024, "accessedAt": "2026-08-30" }, { "label": "FDA list of substances that may present compounding safety risks", "publisher": "U.S. Food and Drug Administration", "url": "https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks", "kind": "Regulatory", "year": 2026, "accessedAt": "2026-08-30" }, { "label": "FDA drug approvals and databases", "publisher": "U.S. Food and Drug Administration", "url": "https://www.fda.gov/drugs/development-approval-process-drugs/drug-approvals-and-databases", "kind": "Regulatory", "year": 2026, "accessedAt": "2026-08-30" }, { "label": "Large randomized TESTS sepsis trial", "publisher": "The BMJ", "url": "https://www.bmj.com/content/388/bmj-2024-082583", "kind": "Randomized trial", "year": 2025, "accessedAt": "2026-08-30" }, { "label": "Correction to the TESTS sepsis trial", "publisher": "The BMJ", "url": "https://www.bmj.com/content/389/bmj.r1098", "kind": "Reference", "year": 2025, "accessedAt": "2026-08-30" }, { "label": "TRACE trial in acute pancreatitis", "publisher": "PubMed · Critical Care", "url": "https://pubmed.ncbi.nlm.nih.gov/35713670/", "kind": "Randomized trial", "year": 2022, "accessedAt": "2026-08-30" }, { "label": "Earlier ETASS sepsis trial", "publisher": "PubMed · Critical Care", "url": "https://pubmed.ncbi.nlm.nih.gov/23327199/", "kind": "Randomized trial", "year": 2013, "accessedAt": "2026-08-30" }, { "label": "Randomized chronic hepatitis B trial", "publisher": "PubMed · Hepatology", "url": "https://pubmed.ncbi.nlm.nih.gov/10607256/", "kind": "Randomized trial", "year": 1999, "accessedAt": "2026-08-30" }, { "label": "2026 Prohibited List", "publisher": "World Anti-Doping Agency", "url": "https://www.wada-ama.org/sites/default/files/2025-09/2026list_en_final_clean_september_2025.pdf", "kind": "Anti-doping", "year": 2026, "accessedAt": "2026-08-30" } ] } }