Thymosin Alpha-1
Also known as: Ta1, Thymalfasin, Zadaxin
Overview
Thymosin Alpha-1 (Tα1) is a 28-amino acid peptide naturally secreted by the thymus gland that plays a central role in T-cell maturation, differentiation, and immune function. It was among the first thymic peptides to be structurally characterized and has been developed into the drug thymalfasin (Zadaxin), which has received FDA orphan drug designation and is approved in multiple countries for hepatitis B, hepatitis C, and certain cancers. It was studied extensively during the COVID-19 pandemic for immune modulation.
Mechanism of Action
Thymosin Alpha-1 modulates multiple immune pathways: enhancing T-helper cell (CD4+) and cytotoxic T-cell (CD8+) function; stimulating dendritic cell maturation and activity; augmenting interferon-gamma and interleukin-2 production; enhancing NK cell cytotoxicity; and reducing T-cell exhaustion. In cancer, it attenuates chemotherapy-induced immune damage. In viral infections, it restores lymphocyte counts and prevents lymphopenia. It also reduces chemotherapy toxicity and acts as a vaccine adjuvant by improving immune response magnitude.
Potential Benefits
- FDA orphan drug designation for malignant melanoma, hepatitis B, DiGeorge anomaly
- Approved in multiple countries for hepatitis B and C treatment
- Reduces chemotherapy-associated immune suppression
- Restores T-cell counts in COVID-19 lymphopenia patients
- Vaccine adjuvant activity enhancing antibody responses
- Reduces mortality in sepsis patients (shown in meta-analysis)
- Anti-tumor immune activation in multiple cancer types
- Modulates dendritic cells to enhance antifungal and antiviral immunity
Dosage Protocols
The following reflects doses used in published research studies. This is not medical advice. Consult a qualified healthcare professional.
| Typical Range | 1.6-3.2 mg twice weekly |
| Beginner | 0.8-1.6 mg twice weekly |
| Intermediate | 1.6 mg twice weekly (standard clinical dose) |
| Advanced | 3.2-6.4 mg twice weekly (intensive immune protocols) |
| Cycle Duration | 4-6 weeks intensive; longer for chronic conditions |
| Cycle Off | 2-4 weeks; maintenance dosing 1x/week may be used long-term |
Zadaxin (pharmaceutical TA1) is dosed at 1.6 mg subcutaneously twice weekly. For immune enhancement in healthy individuals, shorter 4-6 week cycles are typical. Approved in 35+ countries for hepatitis B/C and as cancer adjuvant.
Use our Reconstitution Calculator to determine exact syringe units for your protocol.
Routes of Administration
Subcutaneous Injection High
Approved and standard route; slow absorption provides sustained T-cell stimulation
Intramuscular Injection High
Used in some protocols; comparable efficacy to subcutaneous
Read our full Routes of Administration Guide for detailed comparison of all delivery methods.
Stacking Protocols
Popular research stacks involving Thymosin Alpha-1:
Immune Optimization Stack
Comprehensive immune support, innate defense, and stress-related immune suppression reversal
TA1 drives adaptive T-cell immunity; LL-37 provides innate antimicrobial defense; Selank normalizes anxiety-induced immune dysregulation.
Longevity Immune Stack
Thymic regeneration and immune restoration for age-related immune decline
Both derived from Khavinson's research; complementary targets in thymus-dependent aging.
Oncology Support Stack
Immune support during cancer treatment and cellular survival protection
TA1's proven cancer adjuvant activity combined with Humanin's anti-apoptotic effects.
Explore our complete Peptide Stacking Guide for more combinations and safety considerations.
Reconstitution
| Typical Vial Size | 1.6mg (Zadaxin standard), 10mg (research) |
|---|---|
| BAC Water | 1ml per 1.6mg vial |
| Storage | Refrigerate at 2-8°C after reconstitution |
| Shelf Life | Zadaxin: use immediately after reconstitution; research vials: 28 days refrigerated |
Need exact syringe measurements?
Amino Acid Sequence
Ac-Ser-Asp-Ala-Ala-Val-Asp-Thr-Ser-Ser-Glu-Ile-Thr-Thr-Lys-Asp-Leu-Lys-Glu-Lys-Lys-Glu-Val-Val-Glu-Glu-Ala-Glu-Asn-OH
Side Effects & Safety
- Generally well-tolerated with excellent safety profile
- Mild injection site reactions
- Occasional fatigue
- Rare allergic reactions
Synergistic Compounds
The following compounds have been studied alongside Thymosin Alpha-1 for potential complementary or synergistic effects:
Learn More
References & Further Reading
- [object Object]
- [object Object]
- [object Object]