At a glance
- Thymosin alpha-1 (thymalfasin) is not an FDA-approved drug: Drugs@FDA has no record of it.
- It was on FDA's Category 2 safety-risk list until the nomination was withdrawn. A withdrawal is not an approval.
- PubMed lists 630 publications mentioning it, including 40 randomized controlled trials and 185 animal-only studies.
- ClinicalTrials.gov lists 66 registered studies testing it (20 active).
- FDA's adverse event system (FAERS) holds 247 reports mentioning it; 196 classified as serious. Reports do not prove causation.
Research topics
Most frequent MeSH subject headings in the latest PubMed records (English, as indexed).
Regulatory status
Drugs@FDA applications
No application found in Drugs@FDA, FDA's database of approved drugs.
Source: Drugs@FDA (openFDA) · verified October 30, 2026 · API query
FDA compounding safety list
FDA's stated risk · Original FDA text (English) Compounded drugs containing thymosin-alpha-1 (Ta1) may pose significant risk for immunogenicity for certain routes of administration and may have complexities with regard to peptide-related impurities and API characterization. The safety-related information is inadequate for the agency to sufficiently understand the extent of any safety issues raised by the proposed compounded drug. Source: FDA.gov — Category 2 bulk drug substances · verified October 30, 2026
Removal of a substance from a regulatory list does not mean it has been approved. A "research use only" label does not make a product safe or legal for human use.
Scientific publications
Counts are PubMed records that mention the peptide in the title or abstract. Categories overlap, and a mention is not the same as testing the peptide as a treatment. Each number opens the exact PubMed search. Effects seen in laboratory or animal studies may not occur in humans. A registered clinical trial does not show that a substance is effective or safe.
Latest publications
- Clinical Applications and Evidence Landscape of Thymosin Alpha 1 as an Immunomodulatory Adjunct in Cancer Care: A Scoping Review.
- A prospective clinical study on the effectiveness of Phellinus igniarius decoction in treating immune dysfunction in colorectal cancer patients following chemfotherapy.
- Thymosin Alpha-1 Provides Direct Neuroprotection by Engaging the Orexin Receptor HCRTR1 to Suppress Neuronal Necroptosis.
- Thymosin α-1 in cancer therapy: Immunomodulatory mechanisms, clinical applications, and translational perspectives.
- Thymosin α1 Augments CD8⁺ T-Cell Activation and Reverses Exhaustion In Vitro.
- Thymosin Alpha-1 Restores Chemotherapy-Induced Antitumor Immunity by Chaperoning a MicroRNA Ligand of TLR7 in Dendritic Cells.
- Peptide Therapies in Thyroid Health: Emerging Applications in Endocrine and Immune Modulation.
- Preliminary results from a phase II trial of spatially fractionated radiotherapy combined with immunotherapy and anti-angiogenic therapy in patients with bulky solid tumors: early evidence of promising efficacy and favorable safety.
- Thymalfasin combined with immune checkpoint inhibitors in the treatment of non-small cell lung cancer: A retrospective study on efficacy, safety, and immunological function.
- IL-15 Plus Thymosin α1 Reduces Senescent Hepatic CD8+ T Cells in Hepatocellular Carcinoma via PI3K/AKT Suppression.
Source: PubMed (NCBI) · verified October 30, 2026
Clinical trials
- Registered
- 66
- Active
- 20
- With posted results
- 2
Conditions studied
Show 40 more studies
All 66 studies on ClinicalTrials.gov ↗
Source: ClinicalTrials.gov · verified October 30, 2026
Adverse event reports
- Reports
- 247
- Serious
- 196
- With death outcome
- 31
Most reported reactions
Adverse event reports do not prove that the substance caused these effects. Side effects not listed here may still occur. Reaction terms are MedDRA terms as reported to FAERS.
Source: FDA FAERS (FAERS data as of July 30, 2026) · verified October 30, 2026 · API query
Change history
No changes since monitoring began on October 30, 2026.