← Back to the full Peptide Guide overview
Important Disclaimer — Read Before Using This Page
This information is not intended for use by unlicensed individuals or by licensed professionals who lack adequate training and experience in assessing patients for peptide or hormone therapy. All clinical decisions and dosing must be made in consultation with a licensed, experienced physician and a licensed, experienced compounding pharmacist, and should be supported by published clinical studies.
The information presented here has been compiled using Artificial Intelligence, statements from videos and websites by apparent qualified professionals, and available published research. We strongly encourage exhaustive independent research before considering any therapy. Anyone starting a medication they have never taken before should take an extremely conservative approach.
Nothing on this page or in these videos should be taken as medical advice. These materials are provided only to help begin your research. All dosing and treatment decisions should be made between you and your medical providers after proper evaluation. We are not affiliated with any of the doctors whose videos appear on this page.
Thymosin Alpha-1 Immune Modulator
Also known as: Thymalfasin (international brand: Zadaxin)
Category: Immune Support
How it works. Thymosin Alpha-1 is a 28-amino-acid immunomodulatory peptide that acts through multiple immune signaling pathways including T-cell maturation, dendritic-cell function, natural killer cell activity, cytokine modulation, and Th1/Th2 balance. It is fundamentally different from tissue-repair peptides like BPC-157 and from metabolic peptides like the GLP-1 agonists—it is an immune-active drug .
Why a physician prescribes it. Thymosin Alpha-1 is approved in approximately 37 countries under the brand name Zadaxin (SciClone Pharmaceuticals) for indications including chronic hepatitis B and C, selected cancer immunomodulation, and adjunctive therapy in severe sepsis. It is not FDA-approved as a finished drug in the United States. It is most defensibly prescribed for carefully selected immune-related contexts: recurrent infections that have been properly worked up, immune dysregulation, chronic viral history, post-chemotherapy immune recovery.
Cautions. Be careful in patients with autoimmune disease (stimulating immune function in lupus, rheumatoid arthritis, or inflammatory bowel disease could trigger flares), organ transplant patients on immunosuppression, pregnancy, and severe allergic disease. Side effects are usually mild—injection-site reactions or transient flu-like symptoms as the immune system activates. Fever, severe fatigue, joint pain, or worsening of autoimmune symptoms require prompt evaluation and discontinuation.
• Comprehensive review of Thymosin alpha-1 literature. PMC. 2020.
• TESTS Trial. "Efficacy and safety of thymosin α1 for sepsis." BMJ. 2025.
• FDA Orphan Drug approval: Zadaxin (thymalfasin) for multiple indications.
Recommended Videos
Dr. Jay Campbell — Cody McBroom Podcast — Peptides 101 with Jay Campbell: Healing, Hormones & Human Optimization Explained
Dr. Greg Jones — Enovative Wellness Center — Thymosin Alpha-1: Immune Support & Peptide Therapy Explained
Dr. Adam Sewell, MD — Thymosin Alpha-1: Transforming Immunotherapy for Autoimmune & Cancer Care
Video Sources & Independence
The videos linked on this page are provided solely for educational purposes. None of the physicians or channels featured are sponsored by, affiliated with, or compensated by NJ Weight Loss & Preventive Care Clinics, its physicians, or any individuals associated with our practice. We have selected these videos because they offer thoughtful, evidence-based discussion of mechanisms and clinical considerations. Viewers should evaluate all sources independently.
← Back to the full Peptide Guide overview · Peptide Dosing Reference →