Thymosin Alpha-1 (5mg Vial) Dosage Protocol
Immune-modulating peptide (thymalfasin / Zadaxin) — research/educational dosing reference.
Mix & measure Thymosin Alpha-1 · 5 mg
Pre-filled with this protocol’s recommended BAC water and documented starting dose — edit any field to run your own numbers.
Reconstitution math only — not dosing advice. U-100 syringe: 100 units = 1 mL. Full reconstitution guide → · Advanced calculator →
Quickstart Highlights
Thymosin Alpha-1 (Tα1, thymalfasin) is a naturally occurring 28-amino-acid peptide originally isolated from the thymus gland, recognized for its broad immune-modulating properties[1][5]. This educational page outlines the established subcutaneous regimen using a dilution chosen so the dose lands on easy-to-read insulin-syringe marks. Thymosin Alpha-1 is an approved pharmaceutical (brand Zadaxin / generic thymalfasin) in 35+ countries (including China, Italy, and India) for hepatitis B/C and as an immune adjuvant, but it is not FDA-approved in the United States, where it is investigational — presented here for research and educational use only.
Add 2.0 mL bacteriostatic water to one 5 mg vial → 2.5 mg/mL (2,500 mcg/mL), giving clean insulin-syringe measurements.
1.6 mg per injection, twice weekly — the established clinical dose (~3.2 mg per week).
At 2.5 mg/mL, 1 unit = 25 mcg; 1.6 mg = 64 units (0.64 mL) per injection on a U-100 syringe.
Lyophilized: refrigerate at 2–8 °C or freeze at −20 °C (−4 °F); once reconstituted, refrigerate at 2–8 °C (35.6–46.4 °F) and use within 7 days.
Important: Start with the Prep & Injection Guide — it covers the preparation and safety basics every protocol on this site assumes.
Dosing & Reconstitution Guide
The established subcutaneous dose with a clean dilution, step by step
Standard Approach (2 mL = 2.5 mg/mL)
Reconstitute: Add 2.0 mL bacteriostatic water to one 5 mg vial → final concentration 2.5 mg/mL (2,500 mcg/mL).
Established dose: 1.6 mg subcutaneously, twice weekly (the standard clinical schedule for thymalfasin).
Easy measuring: At 2.5 mg/mL, 1 unit = 25 mcg on a U-100 syringe, so 1.6 mg = 64 units (0.64 mL) — well within the precise range of the syringe.
Storage: Lyophilized: refrigerate at 2–8 °C or freeze at −20 °C (−4 °F); after reconstitution, refrigerate at 2–8 °C (35.6–46.4 °F) and use within 7 days.
Frequency: one subcutaneous injection of 1.6 mg twice weekly (for example Monday and Thursday). This is the standard thymalfasin schedule used in hepatitis B and immune-adjuvant studies, giving a weekly total of 3.2 mg[3][4]. Course lengths of 8–26 weeks are commonly reported. Outside the countries where it is approved, these figures are for research and educational reference only.
Reconstitution Steps
Draw 2.0 mL of bacteriostatic water into a sterile syringe.
Release it slowly down the vial’s inner wall to limit foaming.
Swirl or roll gently until fully dissolved — don’t shake.
Label with the date and concentration, then refrigerate at 2–8 °C (35.6–46.4 °F), shielded from light.
The 2.0 mL dilution gives 2.5 mg/mL so the 1.6 mg dose reads at 64 units (0.64 mL), well within the precise range of a U-100 syringe. Avoid freezing the reconstituted solution, since freeze–thaw can denature the peptide.
Important: This guide is for educational purposes only and is not medical advice. For research use only. Not for human consumption.
Supplies Needed
Quantities below assume an 8–26 week course at 1.6 mg subcutaneously twice weekly.
A 5 mg vial yields three 1.6 mg doses, but reconstituted solution should be used within 7 days, so plan about one vial per week.
- 8 weeks: ~8 vials
- 12 weeks: ~12 vials
- 26 weeks: ~26 vials
- Per week (2 injections): 2 syringes
- 8 weeks: ~16 syringes
- 26 weeks: ~52 syringes
Use 2.0 mL per 5 mg vial for reconstitution.
- 8 weeks (8 vials): ~16 mL → 2 bottles
- 26 weeks (26 vials): ~52 mL → 6 bottles
One for the vial stopper + one for the injection site each day.
- Per injection: 2 swabs
- 8 weeks (2×/week): ~32 swabs → 1 box
Protocol Overview
A concise summary of the standard twice-weekly regimen, drawn from clinical thymalfasin protocols.
- ▪Goal: Modulate immune function — enhancing T-cell maturation, dendritic-cell activity and regulated cytokine output[5][6].
- ▪Schedule: Subcutaneous injections twice weekly; courses commonly run 8–26 weeks depending on the indication.
- ▪Dose: 1.6 mg per injection, twice weekly (about 3.2 mg per week) — the established clinical dose.
- ▪Reconstitution: 2.0 mL bacteriostatic water per 5 mg vial gives 2.5 mg/mL (1.6 mg = 64 units).
- ▪Storage: Keep the dry vial refrigerated at 2–8 °C or frozen at −20 °C; once mixed, refrigerate at 2–8 °C and use within 7 days.
Dosing Protocol
The standard twice-weekly approach based on clinical thymalfasin dosing.
- ▪Standard dose: 1.6 mg subcutaneously per injection — no titration needed.
- ▪Frequency: Twice weekly, spaced a few days apart (e.g. Monday and Thursday).
- ▪Weekly total: About 3.2 mg per week across the two injections.
- ▪Cycle Length: Commonly 8–26 weeks depending on the protocol and indication.
- ▪Timing: Inject on consistent days each week and rotate injection sites systematically.
Storage Instructions
Correct storage is what preserves the peptide’s stability and activity.
- ▪Lyophilized: Hold the dry vial at 2–8 °C short-term or −20 °C (−4 °F) long-term, in dry, dark conditions and limit moisture exposure[7].
- ▪Reconstituted: Refrigerate at 2–8 °C (35.6–46.4 °F) and use within about 7 days when using bacteriostatic water; do not freeze the mixed solution, as freezing can denature peptides[8].
- ▪Handling: Let frozen vials warm to room temperature before opening so condensation won’t form, and keep the solution clear of heat and direct light.
- ▪Freeze–thaw: Avoid repeated freeze–thaw cycles of the reconstituted solution.
Important Notes
Practical points that keep daily administration safe and consistent.
- ▪Sterile technique: Use a fresh sterile U-100 insulin syringe each time and drop it straight into a puncture-proof sharps container afterward.
- ▪Site rotation: Move between abdomen, thighs and upper arms to reduce local irritation and lipohypertrophy[9].
- ▪Slow injection: Push the plunger slowly and pause a few seconds before withdrawing the needle to prevent backflow.
- ▪Recordkeeping: Log the daily dose, injection site and any observations to keep the protocol consistent.
- ▪Regulatory note: Thymosin Alpha-1 (Zadaxin / thymalfasin) is an approved medicine in 35+ countries but is not FDA-approved in the United States, where it remains investigational and is used for research and educational purposes only[10].
How This Works
Thymosin Alpha-1 (Tα1, thymalfasin) is a naturally occurring 28-amino-acid peptide first isolated from thymosin fraction 5 of the thymus gland[1][2]. It acts as a broad immune modulator rather than a tissue-repair peptide.
Its primary mechanism centers on T-cell maturation and function: Tα1 promotes the differentiation of precursor cells into mature T-lymphocytes, augments dendritic-cell activity, and signals largely through Toll-like receptors (notably TLR-2 and TLR-9) to help regulate both innate and adaptive immune responses[5][6].
By restoring more balanced immune signalling, it has been studied to enhance host defence in settings where immunity is impaired — including chronic hepatitis B and C, as an adjuvant alongside vaccines, and in critically ill patients. It also helps modulate the production of key cytokines such as interferon and interleukin-2[4].
Approval status: Thymosin Alpha-1 is an approved pharmaceutical — marketed as Zadaxin (generic thymalfasin) in 35+ countries, including China, Italy and India, for hepatitis B/C and as an immune adjuvant. The standard clinical dose is 1.6 mg subcutaneously twice weekly[4].
In the United States it is not FDA-approved and is considered investigational. The information here describes the established international dosing and is presented for research and educational purposes only.
Lifestyle Factors
Habits that may support immune health alongside the protocol.
- ▪Nutrition: Eat a nutrient-dense diet rich in vitamins C and D and zinc to support immune function.
- ▪Activity: Engage in moderate, regular physical activity to complement immune optimisation.
- ▪Sleep: Aim for 7–9 hours, since adequate sleep is closely tied to healthy immune responses.
- ▪Stress & substances: Manage stress and avoid excessive alcohol and smoking, all of which impair immune function.
Potential Benefits & Side Effects
What clinical and preclinical literature describe; thymalfasin has a well-documented safety profile, though individual results vary.
Potential Benefits
- ▪Immune modulation (clinical): Enhances T-cell maturation and function and overall immune competence, studied in chronic hepatitis B/C and as a vaccine adjuvant[5][6].
- ▪Antiviral & critical illness: Used as an immune adjuvant in hepatitis and sepsis; meta-analyses report reduced mortality in moderate-to-critical COVID-19 patients[3].
- ▪Tolerability (clinical): Excellent safety profile; 1.6 mg twice weekly for 6–12 months has been well tolerated in clinical use[4].
- ▪Regulatory note: Approved (Zadaxin / thymalfasin) in 35+ countries but not FDA-approved in the US, where use is investigational and research-only[7].
Common Side Effects
- ▪Injection-site reactions: Mild redness, tenderness or soreness can occur; rotating sites helps.
- ▪Mild & transient: Even experimental doses up to 16 mg SC over 12 months showed no significant Tα1-specific toxicity[7].
- ▪US status: Not FDA-approved in the United States; treat as investigational and use only for research and educational purposes.
Injection Technique
General subcutaneous technique, following established clinical best-practice guidance[14][15].
Pre-Injection Preparation
- ▪Wash your hands well with soap and water.
- ▪Wipe the vial stopper with an alcohol swab and let it air-dry.
- ▪Choose a site (abdomen, thigh, or upper arm) and clean it with a fresh alcohol swab, letting it dry fully[15].
- ▪Draw the intended dose, then check for air bubbles and push any out.
Injection Procedure
- ▪Pinch a skinfold at the chosen site between thumb and forefinger.
- ▪Insert the needle into the pinch at a 45–90-degree angle (use 45 degrees if the fat layer is thin)[14].
- ▪Skip aspiration for subcutaneous shots — it isn’t needed[14].
- ▪Press the plunger slowly and steadily until it’s fully down.
- ▪Wait 5–10 seconds, then pull the needle straight out to prevent leakage.
Post-Injection Care
- ▪Drop the used syringe straight into a puncture-proof sharps container — never recap a needle.
- ▪Return the reconstituted vial to the fridge right away.
- ▪Rotate the injection site each day to prevent irritation and lipohypertrophy[9].
- ▪Watch the site for excess redness, swelling, or signs of infection.
Recommended Source
For high-purity research peptides, we point researchers to Prime Lab Peptides as a general supplier. Note that Thymosin Alpha-1 in a 5 mg presentation is not sold there; the link goes to their homepage.
Why Prime Lab Peptides?
- ▪Top-rated on Trustpilot: Independently reviewed as the highest-rated peptide lab on Trustpilot — making it the best current source in the USA.
- ▪Third-party tested: Every batch ships with a Certificate of Analysis (COA) confirming purity and composition.
- ▪Consistent quality: ISO-aligned manufacturing and handling keep product integrity reliable batch to batch.
- ▪Cold-chain integrity: Temperature-controlled shipping and storage across the whole fulfilment chain.
- ▪Research-grade purity: Fit for educational and research use that demands high-quality peptides.
Note: Product availability and specifications subject to change. Verify current product details on supplier website.
References
- 1
World Journal of VirologyDominari et al. (2020): Comprehensive review of Thymosin Alpha-1 mechanisms, dosing (0.8–6.4 mg SC), and clinical applications.
- 2
Molecules (MDPI)Tao et al. (2023): Thymosin Alpha-1 in viral diseases — mechanisms and therapeutic applications in HBV, HCV, and HIV.
- 3
InflammopharmacologySoeroto et al. (2023): Meta-analysis of Tα1 in COVID-19; significant mortality reduction in moderate-to-critical patients.
- 4
Expert Opinion on Biological TherapyThymalfasin (Zadaxin) clinical overview: 1.6 mg SC twice weekly for hepatitis B treatment.
- 5
Annals of the New York Academy of SciencesThymosin Alpha-1: biological activities, clinical applications, and pharmacokinetics review.
- 6
Clinical ImmunologyMechanisms of thymosin alpha-1 immunomodulation: T-cell maturation and cytokine production.
- 7
Thymalfasin Safety ReviewSafety data: Thymosin Alpha-1 doses up to 16 mg SC for 12 months showed no significant Tα1-specific toxicity.
- 8
Bacteriostatic Water GuidanceBacteriostatic water for injection: multi-dose vial stability and handling.
- 9
NCBI BookshelfBest practices for subcutaneous injection: aseptic technique and site rotation.
- 10
FDA / Regulatory StatusThymalfasin (Zadaxin) is approved in 35+ countries for hepatitis B/C and as an immune adjuvant, but is not FDA-approved in the United States.
- 11
Journal of HepatologyThymosin Alpha-1 as an immune adjuvant in chronic hepatitis B and C: clinical efficacy.
- 12
Critical CareThymosin Alpha-1 in severe sepsis and critical illness: immune restoration and outcomes.
- 13
ClinicalTrials.govTrial registry of thymalfasin (Thymosin Alpha-1) studies across hepatitis, oncology and immune indications.
- 14
Centers for Disease Control and Prevention (CDC)Subcutaneous injection technique: angle, site and no-aspiration guidance.
- 15
Subcutaneous Injection Technique (Patient Education)How to administer a subcutaneous injection: clinical technique guidelines.
- 16
Prime Lab PeptidesPrime Lab Peptides supplier homepage — research-grade peptides, purity specifications and certificates of analysis.
How to reconstitute Thymosin Alpha-1
- 1Wipe the vial stopper and your bacteriostatic-water vial with an alcohol swab.
- 2Draw your chosen amount of bacteriostatic water and inject it slowly down the inner wall of the Thymosin Alpha-1 vial.
- 3Let it rest, then gently swirl until fully dissolved — do not shake.
- 4Refrigerate the reconstituted vial and draw each dose with a U-100 insulin syringe.
Thymosin Alpha-1 — frequently asked questions
How do I reconstitute a 5 mg vial of Thymosin Alpha-1?
Wipe the stopper with an alcohol swab, then inject your bacteriostatic water slowly down the inside wall of the vial. Let it sit and gently swirl until dissolved — never shake. Store the mixed vial in the refrigerator and draw doses with an insulin syringe. Use the calculator above to turn any dose into syringe units.
How much bacteriostatic water should I add to Thymosin Alpha-1?
There is no single correct amount — more water simply spreads the same 5 mg of peptide across a larger volume, which makes small doses easier to measure accurately. 1 to 3 mL per vial is typical. Enter your chosen volume in the calculator above to see the resulting concentration and syringe units.
What do the "units" on an insulin syringe mean?
On a U-100 insulin syringe, 100 units equal 1 mL, so 1 unit equals 0.01 mL. The calculator above converts your draw volume into these units automatically so you can measure without doing the math by hand.
How should I store Thymosin Alpha-1 after mixing?
Keep the reconstituted vial refrigerated at roughly 2 to 8 degrees Celsius, away from light, and avoid freezing it. Reconstituted research peptides are generally used within a few weeks. Always follow the specific guidance supplied with your product.
How many doses does a 5 mg vial of Thymosin Alpha-1 provide?
Divide the vial strength of 5 mg by the amount you use per injection. The calculator above reports this as "doses per vial" the moment you enter a dose.
Is Thymosin Alpha-1 approved for human use?
No. Thymosin Alpha-1 is sold strictly for laboratory and research purposes and is not approved by the FDA or other regulators for human use. Everything on this page is research information, not medical advice — consult a licensed healthcare professional before any use.
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