Thymosin Alpha-1

Thymosin Alpha-1 (TA1) is a 28-amino-acid thymic peptide studied for immune modulation, T-cell support, and antiviral research applications.

Profile · 01

Overview

Thymosin Alpha-1 (TA1) is a 28-amino-acid peptide originally isolated from the thymus gland and studied for immunomodulatory properties in chronic viral infections, critical illness, and immune-deficiency settings. It is marketed in multiple countries as thymalfasin for hepatitis B treatment, but it is not FDA-approved in the United States.

Compared with many research peptides, TA1 has a relatively large human evidence base. This page presents an educational once-daily subcutaneous protocol using a practical dilution for clearer insulin-syringe measurements.

At a Glance

Goal
Support immune regulation, T-cell maturation, and antiviral defense signaling
Categories
Immune SupportImmune ModulationAnti-ViralCritical Care
Synergistic
TB-500 (Thymosin Beta-4) · BPC-157 · Zinc · Vitamin D3
Profile · 02

Protocol

Suggested once-daily titration approach with a one-week introductory phase followed by maintenance dosing.

Reconstitute
Add 3.0 mL bacteriostatic water to a 5 mg vial for ~1.67 mg/mL concentration
Typical daily range
300–500 mcg once daily
Start
300 mcg daily for Week 1
Target
500 mcg daily from Week 2 onward (~3.5 mg/week)
Frequency
Once per day (subcutaneous)
Cycle Length
8–12 weeks; optional extension to 16 weeks
Timing
Any consistent time; rotate injection sites
Route
Subcutaneous
Cycle
8–12 weeks on, 4 weeks off

Inject once daily subcutaneously using a dilution that keeps measurements above 10 units per injection on a U-100 insulin syringe. Human studies support a favorable safety profile at established doses, but PepTribe presents this material for education and research discussion only.

Dose progression

Week 1
300 mcg (0.3 mg) · 18 units (0.18 mL)
Weeks 2–8+
500 mcg (0.5 mg) · 30 units (0.30 mL)

Important: This guide is for educational purposes only and is not medical advice. For research use only. Not for human consumption.

Profile · 03

Videos

Science · 01

How Thymosin Alpha-1 works.

Thymosin Alpha-1 is a naturally occurring thymic peptide that modulates immune activity through several pathways. Published work describes support for T-cell maturation and differentiation, dendritic-cell function, and cytokine signaling including interferon-alpha and interleukin-2.

Human clinical literature has evaluated thymalfasin in chronic hepatitis B and C, HIV/AIDS-related immune dysfunction, sepsis, and moderate-to-critical COVID-19 settings. Meta-analytic and trial data suggest immune-support benefits in selected populations, although outcomes vary by disease context and study design.

Science · 02

Effects

Observations from clinical or preclinical literature.

Supports T-cell function and broader immune competence in published human studies
Demonstrates antiviral research relevance in chronic hepatitis B and C trials
Meta-analyses report outcome benefits in moderate-to-critical COVID-19 cohorts
Has a relatively strong human safety record compared with many research peptides
Most common adverse effect reported is mild injection-site irritation or discomfort
Long-term use decisions still require qualified medical oversight because outcomes depend on the underlying clinical context
Science · 03

Caution

Individuals with organ transplants receiving immunosuppressive therapy should avoid immune-stimulating protocols unless specifically directed by a qualified clinician
Not recommended during pregnancy or breastfeeding because safety data is insufficient
Use caution in autoimmune conditions because immune modulation may be unpredictable
Consult a qualified healthcare provider before use if you have chronic medical conditions or take immunomodulatory medications

Important: This guide is for educational purposes only and is not medical advice. For research use only. Not for human consumption.

Lifestyle · 01

CoFactors

Zinc
Essential for T-cell development and immune function; deficiency can impair immune resilience.
Vitamin D3
Supports innate and adaptive immune signaling and is commonly paired with immune-support protocols.
Vitamin C
Supports immune cell function and antioxidant defense during inflammatory stress.
Selenium
Supports immune regulation and antioxidant enzyme systems such as glutathione peroxidase.
Lifestyle · 02

Life Factors

Complementary strategies for best outcomes.

Maintain a nutrient-dense diet with adequate protein, zinc, vitamin D, and vitamin C intake
Prioritize 7–9 hours of sleep because immune recovery is highly sleep-dependent
Use moderate physical activity and avoid overtraining, which can suppress immune function
Limit smoking and excessive alcohol intake because both can impair immune resilience
Lifestyle · 03

Metrics

Day-to-day metrics worth tracking through the protocol.

  1. Illness frequency and duration — track whether infection susceptibility or recovery patterns change over time
  2. Energy levels and general well-being — useful for observing recovery and overall resilience trends
  3. Sleep quality and recovery perception — poor sleep can counteract immune-support goals
  4. Injection-site reactions — note redness, swelling, or discomfort to guide site rotation
Lifestyle · 04

Labs

Baseline and periodic bloodwork to monitor systemic health during the protocol.

CBC with Differential
Monitor white blood cell counts and general immune-cell trends.
CD4/CD8 T-cell Counts
Directly relevant to T-cell populations discussed in TA1 research.
CRP (C-Reactive Protein)
General inflammation marker to track before and during the protocol.
Vitamin D (25-OH)
Useful for confirming sufficiency in a protocol centered on immune support.
CMP (Comprehensive Metabolic Panel)
Assesses liver and kidney function during peptide use.
Calculators · 01

Supplies Calculator

Estimates assume the schedule defined for this peptide.

Length
Vial size
Bac. water
Syringe
Vials
0 × 5 mg each…
Syringes
0
Bac. water
0 mL
Swabs
02 per syringe
Calculators · 02

Dose Calculator

Dose Calculator

Vial
Bac. water
Syringe
Dose
Concentration
0mcg/mL
Volume per dose
0mL
…
Practice · 01

Preparation

Careful technique preserves potency. Solution should be clear — do not shake.

  1. Allow vial to reach room temperature for 15–20 minutes before reconstitution.
  2. Draw the chosen bacteriostatic water volume with a sterile syringe.
  3. Inject slowly down vial wall; avoid foaming.
  4. Gently swirl/roll until dissolved (do not shake).
  5. Label with reconstitution date and refrigerate at 2–8 °C (35.6–46.4 °F), protected from light.
  6. Use within 30 days; discard any unused solution after 30 days.
Practice · 02

Technique

General subcutaneous guidance from clinical best-practice resources.

Clean the vial stopper and skin with alcohol; allow both to dry fully
Pinch a skinfold and insert the needle at 45–90° into subcutaneous tissue
Do not aspirate for subcutaneous injections; inject slowly and steadily
Rotate sites systematically across the abdomen, thighs, and upper arms to reduce lipohypertrophy risk
Discard used syringes immediately in an appropriate sharps container

Important: This guide is for educational purposes only and is not medical advice. For research use only. Not for human consumption.

Practice · 03

Storage

Lyophilized
Store at room temp in dry, dark conditions; minimize moisture exposure.
Reconstituted
Refrigerate at 2–8 °C (35.6–46.4 °F); avoid freeze–thaw cycles. Discard reconstituted vials after 30 days.

Notes

Allow vials to reach room temperature before opening to reduce condensation uptake.
Reference · 01

Notes

Use a new sterile insulin syringe for each injection and dispose of it safely
At the listed 3.0 mL reconstitution, 1 unit on a U-100 insulin syringe is approximately 16.7 mcg
Inspect the solution before each use and do not use it if it appears cloudy or discolored
Document daily dose and injection-site rotation to improve consistency
PepTribe is an educational platform. This information is for research and learning purposes only and is not medical advice.
Reference · 02

References

  1. Journal of Biological Regulators and Homeostatic Agents
    Garaci E et al., "Thymosin alpha-1: from bench to bedside".
    https://pubmed.ncbi.nlm.nih.gov/10394742/
  2. Annals of the New York Academy of Sciences
    Goldstein AL et al., "Thymosin alpha-1: thymic hormone or biological response modifier?".
    https://pubmed.ncbi.nlm.nih.gov/17404022/
  3. Expert Opinion on Biological Therapy
    Tuthill C et al., "Thymalfasin: clinical pharmacology and antiviral applications".
    https://pubmed.ncbi.nlm.nih.gov/20462368/
  4. International Immunopharmacology
    Li J et al., "Thymosin alpha-1 in COVID-19: meta-analysis of clinical outcomes".
    https://pubmed.ncbi.nlm.nih.gov/33971440/
  5. Clinical Infectious Diseases
    Andreone P et al., "Thymosin alpha-1 plus interferon-alpha for hepatitis C: randomized controlled trial".
    https://pubmed.ncbi.nlm.nih.gov/11170939/
  6. WHO (NCBI Bookshelf)
    Guideline on safety-engineered syringes for IM, ID, and SC injections in health care settings (2016).
    https://www.ncbi.nlm.nih.gov/books/NBK390474/
  7. Johns Hopkins Arthritis Center
    How to give a subcutaneous injection (patient education resource).
    https://www.hopkinsarthritis.org/patient-corner/how-to-give-a-subcutaneous-injection/
  8. CDC
    Vaccine administration: subcutaneous route (angle/site; no aspiration).
    https://www.cdc.gov/vaccines/hcp/admin/downloads/YCTS-VaxAdmin-Subcut-injection.pdf
  9. PMC
    Pharmacologic considerations of the subcutaneous route.
    https://pmc.ncbi.nlm.nih.gov/articles/PMC6822791/
  10. Drugs.com
    Zadaxin (thymalfasin) international product information and approvals.
    https://www.drugs.com/international/zadaxin.html
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