Thymosin Alpha-1 (5 mg Vial) Dosage Protocol

Plan based on an 8–16 week daily protocol with gradual titration.

• Peptide Vials (Thymosin Alpha-1, 5 mg each):
  • 8 weeks: approximately 6 vials required
  • 12 weeks: approximately 9 vials required
  • 16 weeks: approximately 12 vials required
• Insulin Syringes (U‑100):
  • Per week: 7 syringes (1/day)
  • 8 weeks: 56 syringes
  • 12 weeks: 84 syringes
  • 16 weeks: 112 syringes
• Bacteriostatic Water (10 mL bottles): Use ~3.0 mL per vial for reconstitution.
  • 8 weeks (6 vials): 18 mL — 2 bottles required (10 mL each)
  • 12 weeks (9 vials): 27 mL — 3 bottles required (10 mL each)
  • 16 weeks (12 vials): 36 mL — 4 bottles required (10 mL each)
• Alcohol Swabs: One for the vial stopper + one for the injection site each day.
  • Per week: 14 swabs (2/day)
  • 8 weeks: 112 swabs — 2 boxes required (100 swabs each)
  • 12 weeks: 168 swabs — 2 boxes required (100 swabs each)
  • 16 weeks: 224 swabs — 3 boxes required (100 swabs each)

Thymosin Alpha-1 5 mg

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U-100 syringes

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Bacteriostatic water

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Alcohol swabs

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• Reconstitute: Add 3.0 mL bacteriostatic water → ~1.67 mg/mL concentration.
• Typical daily range: 300–500 mcg once daily (gradual titration).
• Easy measuring: At 1.67 mg/mL, 1 unit = 0.01 mL ≈ 16.7 mcg on a U‑100 insulin syringe.
• Storage: Lyophilized: refrigerate at 2–8 °C (35.6–46.4 °F) or freeze at −20 °C (−4 °F); after reconstitution, refrigerate and follow product-specific use-by instructions.

Thymosin Alpha-1 (Tα1) is a 28–amino acid peptide originally isolated from the thymus gland, recognized for its broad immunomodulatory properties^[1]. It has been investigated as an immune enhancer in chronic viral infections (hepatitis B/C, HIV/AIDS) and critical illness (sepsis, COVID-19)^[2][3]. This educational protocol presents a once‑daily subcutaneous approach using a practical dilution for clear insulin‑syringe measurements.

A 5 mg vial describes the total peptide mass in the container. This vial strength, prepared with the page’s established 3.0 mL water volume, yields a concentration of approximately 1.67 mg/mL.

• Compound: Thymosin Alpha-1 (Tα1), also known as thymalfasin.
• Vial strength: 5 mg total peptide mass.
• Final liquid volume: 3.0 mL.
• Calculated concentration: 5 mg ÷ 3.0 mL = approximately 1.67 mg/mL.
• U-100 conversion: 1 unit = 0.01 mL = approximately 16.7 mcg at this concentration.

The established chart amounts translate to larger syringe volumes than the 10 mg strength because the 5 mg vial is less concentrated when both are prepared to 3.0 mL.

• 300 mcg calculation: 0.30 mg ÷ 1.67 mg/mL ≈ 0.18 mL = 18 U-100 units.
• 500 mcg calculation: 0.50 mg ÷ 1.67 mg/mL ≈ 0.30 mL = 30 U-100 units.
• Vial yield: One 5 mg vial contains about 16 administrations at 300 mcg or 10 administrations at 500 mcg, before normal handling losses.
• Measurement rule: Recalculate every marking if the final volume changes; U-100 units indicate liquid volume, not peptide IU.

Thymosin Alpha-1 is a synthetic 28-amino-acid peptide corresponding to a naturally occurring thymic peptide first isolated from thymosin fraction 5. In publications it may appear as thymosin alpha 1, thymosin α1, Tα1, or thymalfasin.^[1][5]

Research has focused on immune-response regulation, including dendritic-cell maturation, T-cell differentiation, natural-killer-cell activity, toll-like-receptor signaling, and cytokine networks. These mechanisms do not establish a universal treatment amount or a general health benefit.^[2][6]

Concentration is calculated by dividing 5 mg by the final 3.0 mL liquid volume. That produces approximately 1.67 mg/mL, or 1,667 mcg per millilitre. Because a U-100 insulin syringe has 100 volume markings per mL, one unit represents 0.01 mL and approximately 16.7 mcg at this concentration.

For example, 18 units is 0.18 mL. Multiplying 0.18 mL by 1,667 mcg/mL gives approximately 300 mcg. Likewise, 30 units is 0.30 mL, which converts to approximately 500 mcg. Small-volume measurement accuracy depends on the syringe, its graduations, and careful technique.^[8]

The same unit marking must not be copied to a vial prepared at another concentration. A 5 mg vial and a 10 mg vial can contain the same molecule while requiring different syringe volumes for the same peptide mass.

Published human studies do not identify one dose of Thymosin Alpha-1 for every condition. A chronic hepatitis B trial evaluated 1.6 mg subcutaneously twice weekly, while liver-failure and sepsis investigations used condition-specific schedules, formulations, administration periods, and endpoints.^[4][15][17]

The name Zadaxin appears in clinical and regulatory literature as a characterized thymalfasin product. Findings from that product cannot automatically validate a separate research vial or dosing protocol.^[7][15]

The 2025 TESTS phase 3 trial enrolled 1,106 adults with sepsis and evaluated administration every 12 hours for seven days. It did not show a clear reduction in 28-day all-cause mortality compared with placebo, an important counterpoint to favorable signals in some smaller studies and meta-analyses.^[12][3]

Study schedules are tied to their populations, protocols, and characterized products. They should not be presented as proof that an educational vial-conversion chart is clinically validated.

Thymosin Alpha-1 is commonly described as an immune-response modulator rather than a simple immune stimulant. Laboratory research discusses dendritic cells, T lymphocytes, NK cells, innate immune receptors, and context-dependent cytokine signaling. Mechanistic papers also examine how the peptide acts on toll-like receptors; those laboratory findings do not establish a clinical outcome.^[1][2][6]

A mechanistic effect does not guarantee a clinical outcome. Controlled outcomes, population details, formulation, route, and duration are necessary when interpreting whether a biological signal translates into efficacy.^[12]

A small crossover study in healthy volunteers compared three subcutaneous Thymosin Alpha-1 formulations. Mean time to peak plasma concentration was approximately one to two hours, the reported elimination half-life was under three hours, and plasma exposure differed among formulations.^[14]

Those findings show why product and formulation details matter. Pharmacokinetic observations do not independently determine a suitable administration frequency or validate the schedule displayed in a separate calculation guide.

Clinical and translational research has examined Thymosin Alpha-1 in chronic hepatitis B and C, sepsis, viral illness, vaccine adjuvant settings, immunodeficiency, and as an adjunct in some cancer studies. Reviews also discuss exploratory work involving lung cancer, breast cancer, autoimmune disease, and immune function.^[1][2][5]

Results vary across indications. Some older hepatitis studies reported delayed virologic responses, while other trials and modern controlled studies produced uncertain or neutral findings. Differences in patient selection, disease severity, combination therapy, and endpoints limit broad conclusions.^[4][12][15]

Thymosin Alpha-1 is not a conventional direct antiviral drug. Its proposed actions involve host immune pathways, so changes in immune markers should not be equated with a guaranteed clinical benefit.^[2][6]

• Mixed clinical outcomes: Smaller studies and reviews sometimes report favorable signals, but the large phase 3 sepsis trial was neutral for its primary mortality outcome.^[3][12]
• Condition-specific evidence: Hepatitis, COVID-19, liver failure, sepsis, and cancer-adjunct research cannot be combined into one universal dosage claim.^[2][16][17]
• Formulation dependence: Exposure can differ across formulations, limiting direct comparison between a research vial and a clinical-study product.^[14]
• Calculation versus evidence: Correct concentration math does not prove safety, efficacy, or suitability for human use.

Published trials often describe adverse events as mild or similar to comparator groups, with injection-site reactions among the practical concerns. Safety findings still depend on the formulation, route, population, duration, disease state, and concomitant therapy.^[5][7]

Thymosin Alpha-1 is not FDA-approved in the United States. The FDA has identified potential immunogenicity, aggregation, and peptide-impurity concerns for compounded Thymosin Alpha-1 and has stated that available safety information is inadequate to fully characterize risks of proposed compounded products. That regulatory concern is separate from results obtained with characterized products in controlled trials.^[18]

This page provides research and educational information. It does not establish medical advice, a standard of care, or a treatment recommendation.

For any study or clinician-directed subcutaneous procedure, the exact product instructions, protocol, route, device, and site guidance take priority. General injection references emphasize hand hygiene, a new sterile syringe, a clean vial stopper and skin, suitable subcutaneous tissue, and the need to rotate injection sites systematically.^[9][10][11]

On this 5 mg page, 18 and 30 units are volume conversions for the stated 1.67 mg/mL concentration. They are not peptide IU and cannot be transferred unchanged to another vial strength or final volume.

Confirm the labeled compound, 5 mg strength, lot-specific certificate of analysis (CoA), and product-specific handling instructions before laboratory research use. The Pure Lab Peptides product page identifies the pictured 5 mg vial and its batch-documentation context; it is not scientific support for a clinical efficacy or dosing claim.^[13]

What concentration results from adding 3 mL to a 5 mg vial?

The calculated concentration is 5 mg ÷ 3.0 mL, or approximately 1.67 mg/mL. Each U-100 unit is 0.01 mL and therefore contains approximately 16.7 mcg at this concentration.

How many U-100 units equal 300 mcg from this preparation?

Approximately 18 units, or 0.18 mL. The conversion applies only to a 5 mg vial prepared to a 3.0 mL final volume.

How many U-100 units equal 500 mcg?

Approximately 30 units, or 0.30 mL, at the stated 1.67 mg/mL concentration.

Is a 5 mg vial the same as a 5 mg dose?

No. Five milligrams is the total mass in the vial. The amount per administration is a separate value calculated from the concentration and liquid volume.

Why are the unit markings different from the 10 mg page?

With the same 3.0 mL final volume, the 5 mg vial is half as concentrated as the 10 mg vial. The same peptide mass therefore occupies twice the liquid volume.

Does Thymosin Alpha-1 have one standard dosage protocol?

No. Human studies have used different condition-specific schedules, populations, formulations, and endpoints. No single research schedule can be generalized across those settings.^[4][12][17]

Can a dosage calculator replace the page’s concentration math?

No. A calculator can check arithmetic, but the labeled vial mass, final volume, concentration, syringe graduations, and protocol inputs still have to be verified independently.

The chart is an educational concentration and syringe-volume calculation using the page’s established schedule. Published clinical-study schedules differ. The calculations are not medical advice, a standard of care, or evidence that a particular preparation is safe or effective.

• 1
  World Journal of Virology — Dominari et al. (2020): comprehensive review of Thymosin Alpha-1 mechanisms and clinical research

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• 2
  Molecules — Tao et al. (2023): mechanisms and clinical research in viral infectious diseases

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• 3
  Inflammopharmacology — Soeroto et al. (2023): systematic review and meta-analysis of Tα1 in COVID-19

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• 4
  Hepatology — Chien et al. (1998): randomized chronic hepatitis B trial using 1.6 mg subcutaneously twice weekly

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• 5
  Annals of the New York Academy of Sciences — Garaci et al. (2007): biological activities and clinical applications review

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• 6
  Clinical Immunology — Romani et al. (2007): immunomodulatory mechanisms of Thymosin Alpha-1

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• 7
  FDA Pharmacy Compounding Advisory Committee — December 2024 Thymosin Alpha-1 briefing and safety review

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• 8
  Hospital Pharmacy — Jordan et al.: accuracy and precision considerations when measuring small liquid volumes with syringes

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• 9
  Centers for Disease Control and Prevention — general subcutaneous route, needle, and site guidance in vaccine administration

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• 10
  Johns Hopkins Arthritis Center — patient guidance for subcutaneous injection site selection and rotation

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• 11
  NCBI Bookshelf — injection preparation, asepsis, site rotation, and administration practices

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• 12
  BMJ — Wu et al. (2025): multicenter, double-blind, placebo-controlled TESTS phase 3 sepsis trial

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• 13
  Pure Lab Peptides — Thymosin Alpha-1 5 mg vial and batch-documentation context

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• 14
  International Journal of Clinical Pharmacology and Therapeutics — pharmacokinetics of three subcutaneous Thymosin Alpha-1 formulations in healthy volunteers

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• 15
  Journal of Gastroenterology — phase 3 multicenter placebo-controlled chronic hepatitis B trial

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• 16
  International Immunopharmacology — systematic review and meta-analysis of adult COVID-19 clinical outcomes

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• 17
  Journal of Viral Hepatitis — randomized controlled trial in hepatitis B virus-related acute-on-chronic liver failure

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• 18
  U.S. Food and Drug Administration — significant safety-risk concerns for compounded Thymosin Alpha-1

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Explore the available research context, protocol variants or comparisons, and practical guides. When vial-strength variants exist, they remain separate because vial strength, concentration, and syringe-unit calculations can differ. Related compounds and blends are comparisons only, not interchangeable.