TB-500 Reconstitution: How Much Bacteriostatic Water
A 10 mg vial of TB-500 reconstituted with 2 mL of bacteriostatic water gives a concentration of 5 mg/mL; with 1 mL it gives 10 mg/mL. The calculation depends only on the quantity in the vial and the volume of water added, so the figures below apply to any 10 mg vial.
There is no single correct volume. Adding more water does not change how much is in the vial. It spreads the same quantity through a larger volume, which changes how many syringe units correspond to a given amount. The tables on this page use volumes that produce round numbers on a U-100 syringe; other volumes work identically as long as the resulting concentration is written on the vial.
Peptide reconstitution calculator
Set to this vial below. Change the vial size, water volume, amount or syringe and it recalculates the concentration and the syringe units. For laboratory research use only.
All products are sold strictly for laboratory research use only and are not for human or veterinary consumption. This calculator is provided as a general reference tool.
How much bacteriostatic water for 10 mg TB-500?
Add 2 mL of bacteriostatic water to a 10 mg TB-500 vial for 5 mg/mL, so 0.1 mL (10 units) holds 0.5 mg; 1 mL gives 10 mg/mL, 3 mL gives 3.33 mg/mL and 5 mL gives 2 mg/mL. Concentration is the quantity in the vial divided by the water volume: the vial holds 10 mg whichever volume you choose, and only the mg/mL figure moves.
| Water added | Concentration | Amount in 0.1 mL (10 units on a U-100 syringe) |
|---|---|---|
| 1 mL | 10 mg/mL | 1 mg |
| 2 mL | 5 mg/mL | 0.5 mg (500 mcg) |
| 3 mL | 3.33 mg/mL | 0.33 mg (333 mcg) |
| 5 mL | 2 mg/mL | 0.2 mg (200 mcg) |
Before choosing a larger volume, check that the vial has headspace for it. One multi-dose vial of bacteriostatic water covers several research vials.
Reading the concentration on a U-100 syringe
A U-100 insulin syringe is graduated in units, and 100 units equal 1 mL. Units are therefore millilitres multiplied by 100: 0.1 mL is 10 units and 0.25 mL is 25 units. A 0.5 mL syringe carries 50 units and a 0.3 mL syringe carries 30 units on the same scale, with finer markings that make small volumes easier to read.
To find the volume that contains a given amount, divide the amount by the concentration. At 5 mg/mL (a 10 mg vial with 2 mL of water), the volume that contains 1 mg is 1 divided by 5, which is 0.2 mL, or 20 units. The table below runs the same calculation for four arbitrary amounts. They illustrate the arithmetic and nothing else.
| Amount (illustrative) | Volume at 5 mg/mL | U-100 units |
|---|---|---|
| 0.25 mg | 0.05 mL | 5 units |
| 0.5 mg | 0.1 mL | 10 units |
| 1 mg | 0.2 mL | 20 units |
| 2 mg | 0.4 mL | 40 units |
At 10 mg/mL, which the same vial gives with 1 mL of water, every volume in the table moves in proportion: a 1 mg draw measures 10 units instead of 20. Volumes below about 0.1 mL are hard to read accurately on a 1 mL syringe. Either move to a 0.3 mL or 0.5 mL syringe, or reconstitute with more water so that the same mass occupies a larger, more legible volume.
TB-500 is supplied by Vistara Labs as a lyophilised material for research use. The quantities on this page illustrate the arithmetic of dilution and measurement only.
The TB-500 vial
Vistara Labs supplies TB-500 in a 10 mg lyophilised vial, prepared with bacteriostatic water. TB-500 is also one half of the BPC-157 + TB-500 blend, which has its own reconstitution page. Certificates of analysis for the catalogue are published on the Lab Results page, and the buying questions are answered in buying TB-500 in Canada.
What TB-500 is
TB-500 is a short synthetic peptide built on the active region of thymosin beta-4 (Tβ4), a naturally occurring repair protein (Treadwell 2012). A doping-control laboratory identified the N-terminal acetylated 17-23 fragment of thymosin beta-4 (Ac-LKKTETQ) in material sold as TB-500 (Esposito 2012). The human research is on thymosin beta-4 itself.
In a phase 2 randomized, double-masked, placebo-controlled trial, thymosin beta-4 eye drops improved both signs and symptoms of severe dry eye compared with vehicle, including a 59.1% reduction in corneal fluorescein staining at day 56 (Sosne 2015). A review of the clinical programme reports that in two phase 2 trials in stasis and pressure ulcers, thymosin beta-4 accelerated healing by almost a month in the patients who healed, alongside faster dermal repair in animal models (Treadwell 2012).
Sources: Esposito S et al. Synthesis and characterization of the N-terminal acetylated 17-23 fragment of thymosin beta 4 identified in TB-500, a product suspected to possess doping potential. Drug Test Anal. 2012. PMID 22962027. Sosne G et al. Thymosin β4 significantly improves signs and symptoms of severe dry eye in a phase 2 randomized trial. Cornea. 2015. PMID 25826322. Treadwell T et al. The regenerative peptide thymosin β4 accelerates the rate of dermal healing in preclinical animal models and in patients. Ann N Y Acad Sci. 2012. PMID 23050815.
Reconstitution technique
Let the vial reach room temperature, swab both stoppers, and run the measured water slowly down the inside wall of the vial rather than onto the powder. Swirl or tilt gently until the cake dissolves, never shake, and give any remaining powder a few minutes to settle into solution. Label the vial with the date and the concentration, then keep it refrigerated at 2 to 8 °C and protected from light. The full method, with the reason behind each step, is in how to reconstitute peptides with bacteriostatic water.
Why the solution should look clear
Properly reconstituted TB-500 forms a clear, colourless solution. Cloudiness, strands or a gel that will not disperse usually mean the water went in too fast or the vial was shaken; haze that appears later points to warm or bright storage. The causes are covered in why peptides gel or go cloudy.
Bacteriostatic water, not sterile water
Bacteriostatic water is sterile water with 0.9% benzyl alcohol, a preservative that allows a refrigerated vial to be accessed more than once; plain sterile water is intended for single access. The difference is explained in bacteriostatic water explained.
Frequently asked questions
How much bac water for a 10 mg TB-500 vial?
There is no single correct volume. With 2 mL of bacteriostatic water a 10 mg vial of TB-500 gives 5 mg/mL, so 0.1 mL (10 units) holds 0.5 mg; with 1 mL it gives 10 mg/mL. Adding more water does not change the quantity in the vial, it spreads it through a larger volume, so write the concentration you chose on the vial.
How many units on a U-100 syringe contain 1 mg of TB-500 at 5 mg/mL?
At 5 mg/mL (a 10 mg vial with 2 mL of water), the volume that contains 1 mg is 1 divided by 5, which is 0.2 mL, or 20 units. Units are millilitres multiplied by 100, so 0.1 mL is 10 units. The amounts on this page illustrate the arithmetic only.
What should reconstituted TB-500 look like?
Properly reconstituted TB-500 forms a clear, colourless solution. Cloudiness, strands or a gel that will not disperse usually mean the water went in too fast or the vial was shaken; haze that appears later points to warm or bright storage. More on the causes in why peptides gel or go cloudy.
Can I use sterile water instead of bacteriostatic water?
Only for a vial that will be accessed once. Bacteriostatic water is sterile water with 0.9% benzyl alcohol, a preservative that allows a refrigerated vial to be accessed more than once; plain sterile water is intended for single access. Details in bacteriostatic water explained.
How should a reconstituted TB-500 vial be stored?
Refrigerated at 2 to 8 °C, protected from light and labelled with the date and the concentration. Unopened lyophilised vials are kept cold and dark until they are needed. The full storage guide is how to store research peptides.
Work it out for a different vial or concentration
Our peptide calculator opens pre-set for a 10 mg vial with 2 mL of water and marks the 1 mg draw of 20 units on a syringe diagram. Change the vial size, water volume, amount or syringe and it recalculates.
Products: TB-500 10 mg, BPC-157 + TB-500 blend and bacteriostatic water.
All products supplied by Vistara Labs are intended for laboratory research use only. They are not drugs, are not approved for human or veterinary use, and are not intended to diagnose, treat, cure or prevent any condition. Nothing on this page constitutes medical advice or guidance for use in humans.
