Thymosin Alpha-1
Thymosin alpha-1 is a 28-amino-acid synthetic peptide identical to the endogenous thymic peptide, studied in immune-modulation research models.
Switching categories completely, because peptides are not all tissue repair. Some of the most-studied ones are about your immune system.
We have not published an audit on Thymosin Alpha-1. Everything below is reference material, not our own reading of the literature, treat it as a starting point for questions, not as a grade.
How it is thought to work
Potential T-cell and immune signaling modulation.
Thymosin Alpha-1 is a peptide your thymus naturally makes that helps train and activate immune cells to fight viruses and infections; the synthetic version has been approved in over 35 countries for hepatitis B, hepatitis C, and cancer immune support.
Reported side effects
TA1 is generally very well tolerated, the most common side effects are mild injection-site redness or soreness and, in hepatitis patients, a temporary rise in liver enzymes, while fatigue and flu-like symptoms occasionally occur early in treatment.
Who should avoid it
People who should avoid TA1 without specialist supervision include organ transplant recipients on anti-rejection drugs, those with active autoimmune flares, pregnant or breastfeeding women, anyone under 18, and anyone with a known allergy to TA1 or its components.
What gets monitored
ALT levels should be monitored during therapy, especially in HBV/HCV use. [Source: Peptide Dosing Protocols]
What sources report
These are figures published elsewhere, reproduced with their source. Peppersite does not recommend an amount for Thymosin Alpha-1 or for anything else, and nothing below has been checked against the study it came from.
| Amount | Frequency | Route | Reported by |
|---|---|---|---|
| 1.5 mg SC twice weekly, or 450-900 mcg daily | twice weekly, or daily4-12 weeks · Repeat course per provider direction | subcutaneous | Commonly published practitioner dosing range - provider confirmation required. |
| 1.6 mg | Twice weekly (standard); daily during chemotherapy | subcutaneous or oral | Peptide Protocol WikiWhat it saysHide(secondary reference; provider confirmation required). |
| Standard: 1.6 mg | Twice weekly6 to 12 months · 12 weeks Community-derived, not from a clinical trial These durations are reported from research, not personal-use recommendations. | Subcutaneous | Peptide Dosing ProtocolsWhat it saysHide(secondary reference; provider confirmation required). Half-life: half-life of about 2-3 hours. The standard dosing for TA1 is 1.6 mg subcutaneously twice weekly. |
| Cycling reference for immune support: 6-12 weeks on, 6 weeks off. | not statedOn-cycle 6-12 weeks, off-cycle 6 weeks | subcutaneous | Peptide Therapy Reference Text, internal KB v4What it saysHide(Aug 2026), secondary reference; provider confirmation required. |
- twice weekly, or daily4-12 weeks · Repeat course per provider direction
- subcutaneous
- Commonly published practitioner dosing range - provider confirmation required.
- Twice weekly (standard); daily during chemotherapy
- subcutaneous or oral
- Peptide Protocol Wiki
What it saysHide
(secondary reference; provider confirmation required).
- Twice weekly6 to 12 months · 12 weeks Community-derived, not from a clinical trial These durations are reported from research, not personal-use recommendations.
- Subcutaneous
- Peptide Dosing Protocols
What it saysHide
(secondary reference; provider confirmation required). Half-life: half-life of about 2-3 hours. The standard dosing for TA1 is 1.6 mg subcutaneously twice weekly.
- not statedOn-cycle 6-12 weeks, off-cycle 6 weeks
- subcutaneous
- Peptide Therapy Reference Text, internal KB v4
What it saysHide
(Aug 2026), secondary reference; provider confirmation required.
- Commonly 5 mg or 10 mg vials · Reconstitute with sterile/bacteriostatic water
- Sterile water
- 2 mL bacteriostatic water
Common questions
What is Thymosin Alpha-1 used for?
TA1 is approved internationally for chronic hepatitis B, chronic hepatitis C, and as an immune adjunct in cancer care.
What is the standard Thymosin Alpha-1 dose?
The standard dose is 1.6 mg subcutaneously twice weekly.
How is Thymosin Alpha-1 reconstituted?
A 10 mg vial is reconstituted with 2 mL bacteriostatic water.
Check 10 mg in 2 mL in the calculator →Is Thymosin Alpha-1 FDA-approved?
No, it is not FDA-approved in the United States.
Did the 2025 BMJ TESTS trial prove TA1 works for sepsis?
No, the trial's primary endpoint was negative.
What are the side effects of Thymosin Alpha-1?
Reported side effects are mild and uncommon, including injection-site reactions and transient fatigue.
Who should not use Thymosin Alpha-1?
It should be avoided by organ transplant recipients on immunosuppressive therapy and individuals with known hypersensitivity.
Is Thymosin Alpha-1 the same as TB-500?
No, they are different peptides with distinct functions.
Sources
The reference sections above are imported from our compound knowledge base, which classes the evidence for Thymosin Alpha-1 as clinical. That classification is the knowledge base’s, not ours, our own grade appears only where an audit is linked above. Research use only; nothing here is medical advice or a protocol.
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