TB-500 5 mg vial
How much bacteriostatic water to add to a 5 mg vial of TB-500, the syringe units for each common dose, and how many doses the vial holds.
- Water
- 1 mL
- Strength
- 5 mg/mL
- Common dose
- 2.5 mg
- Draw
- 50 units0.50 mL
- Doses per vial
- 2
The short answer
Mixed with 1 mL of bacteriostatic water, a 5 mg vial of TB-500 holds 5 mg/mL. A 2.5 mg dose is then 50 units (0.50 mL) on a U-100 insulin syringe, and the vial holds about 2 doses of that size. Taken 2× per week, it lasts about 7 days.
How much water
The water only sets the strength; the dose and the number of doses in the vial stay the same. Draws are on a U-100 insulin syringe, where 1 unit is 0.01 mL.
| Water added | Strength | Per syringe unit | Draw for 2.5 mg |
|---|---|---|---|
| 1 mL | 5 mg/mL | 50 mcg | 50 units (0.50 mL) |
| 2 mL | 2.5 mg/mL | 25 mcg | 100 units (1.00 mL) |
| 3 mL | 1.667 mg/mL | 16.7 mcg | 1.50 mL |
Dose chart
Syringe units for each common dose at each water volume. Select a cell to open it in the calculator.
| Dose | Water added | ||
|---|---|---|---|
| 1 mL | 2 mL | 3 mL | |
| 2 mg | |||
| 2.5 mg | |||
| 5 mg | |||
Draws over 100 units show in mL. Faded values are under 2 units, which is hard to measure. Check that your vial holds the larger volumes.
Where the doses come from
- Community Loading: 2–2.5 mg twice weekly for 4–6 weeks.
- Community Maintenance: 2–2.5 mg once weekly or every 2 weeks.
Doses are what labels, trials or community reports reference, not recommendations. TB-500’s page has the cycle, side effects, cautions and sources.
Mixing and storage
- PrepareLet a refrigerated vial come to room temperature, and wipe both stoppers with an alcohol swab.
- Add 1 mLDraw 1 mL of bacteriostatic water and let it run slowly down the inside wall of the vial.
- Swirl, don’t shakeSwirl gently until the powder dissolves and the liquid is clear.
- Label itWrite the date and the strength, 5 mg/mL, on the vial.
Storage: Powder: 2–8 °C, or −20 °C long-term. Mixed: 2–8 °C, use within 2–4 weeks.
The reconstitution guide covers each step, and the units page explains syringe markings.
Questions
How much water do I add to a 5 mg vial of TB-500?
There’s no single right amount: the water only sets the strength. With 1 mL of bacteriostatic water, a 5 mg vial holds 5 mg/mL. With 2 mL it’s 2.5 mg/mL; with 3 mL it’s 1.667 mg/mL. Less liquid makes each dose a smaller draw; more makes small doses easier to measure.
How many units is 2.5 mg of TB-500?
With 1 mL in a 5 mg vial, 2.5 mg is 50 units (0.50 mL) on a U-100 insulin syringe. With 2 mL, 100 units (1.00 mL); with 3 mL, 1.50 mL.
How many doses are in a 5 mg vial of TB-500?
About 2 doses of 2.5 mg, or 2 of 2 mg or 1 of 5 mg. Taken 2× per week at 2.5 mg, it lasts about 7 days.
How long does a mixed vial of TB-500 keep?
Powder: 2–8 °C, or −20 °C long-term. Mixed: 2–8 °C, use within 2–4 weeks.
Other vial sizes
Sources
- Characterization of the TB-500 fragment (PubMed) PMID 22962027
- IV thymosin beta-4 in healthy volunteers, Phase 1 (PubMed) PMID 20536472
- FDA advisory committee backs 6 peptides for compounding (AJMC, July 2026)
The math on this page uses the doses and storage on TB-500’s page.