Why do I use bacteriostatic water instead of regular sterile water?

Bacteriostatic water (BAC water) contains 0.9% benzyl alcohol, which acts as a preservative. This inhibits bacterial growth and keeps your reconstituted peptide solution stable in the refrigerator for several weeks. Plain sterile water has no preservative, so the solution would need to be used almost immediately and carries a higher contamination risk.

How much BAC water should I add to my TB-500 vial?

The amount you choose determines the concentration of your final solution. A 5 mg vial with 1 mL of BAC water gives a concentration of 5 mg/mL; adding 2 mL gives 2.5 mg/mL. There is no single correct answer — it depends on your target research amount per draw. Use our calculator to work out the exact volumes for your specific vial size and desired concentration.

Why should I swirl instead of shake the vial?

Shaking creates foam and applies mechanical stress that can break fragile peptide bonds and potentially degrade the compound. Gentle swirling dissolves the powder just as effectively while keeping the molecular structure intact. TB-500 is a short but structurally specific peptide sequence, so handling it carefully during reconstitution helps preserve its integrity for research use.

How long does a reconstituted TB-500 vial stay good in the fridge?

When stored properly at 2–8 °C and protected from light, a reconstituted TB-500 solution is generally considered stable for up to 4–6 weeks, thanks to the benzyl alcohol preservative in BAC water. Never freeze a reconstituted vial, as ice crystals can damage the peptide. Always inspect for cloudiness or particles before use, and discard if anything looks off.

How to Reconstitute TB-500: Step-by-Step Guide

What Exactly Is TB-500?

Before we touch a needle, a quick bit of context. TB-500 is a synthetic, seven-amino-acid peptide fragment — specifically the sequence Ac-LKKTETQ — derived from the naturally occurring protein thymosin β4.^[5] In preclinical research it has been linked to angiogenesis (new blood-vessel growth), wound healing, and tissue repair.^[3] Reviews of injectable peptide therapies note that TB-500 and its parent molecule promoted these effects in animal models, though human clinical data are still limited.^[2] It is sold for research purposes only and is a banned substance in competitive sport.^[4]

With that framing in mind, let us talk about the practical side: getting the powder into solution so it is ready to use in a research setting.

What You Will Need

Your TB-500 vial (lyophilised — that means freeze-dried powder)
Bacteriostatic water (BAC water) — sterile water with 0.9% benzyl alcohol that keeps the solution from spoiling
Two insulin syringes or small sterile syringes
Alcohol swabs
A clean, flat surface

Step 1 — Warm the Vial

Take the TB-500 vial out of the refrigerator and let it sit at room temperature for about 15–20 minutes. Cold glass plus warm water can cause thermal shock and may affect the peptide. Warming it up first is a small step that makes the powder dissolve more smoothly. Do not heat it with hot water or a microwave — room temperature is all you need.

Step 2 — Wipe Everything Down

Use a fresh alcohol swab to clean the rubber stopper on both your TB-500 vial and your BAC water vial. Let them air-dry for 10 seconds. This is basic sterile technique and it matters — contamination is the enemy of any research preparation.

Step 3 — Draw Your BAC Water

Decide how much BAC water to add. A common starting point for a 5 mg vial is 1–2 mL of BAC water, but the exact volume determines your concentration, so the maths matters. Draw the chosen volume of BAC water into your syringe slowly and steadily. Check for air bubbles; tap the syringe gently and push them out.

Step 4 — Add the Water Slowly Along the Side

This is the most important step. Insert the needle into the TB-500 vial and angle it so the BAC water runs down the inside wall of the glass, not straight onto the powder. Add it in small increments — do not dump it all in at once. Forcing liquid directly onto lyophilised peptide can damage the structure. Patience here pays off.

Step 5 — Swirl, Do Not Shake

Once all the water is in, gently swirl the vial in a slow circular motion. Think of swirling a fine wine, not shaking a cocktail. Shaking creates foam and mechanical stress that can degrade sensitive peptide bonds. Swirl until the powder is completely dissolved and the liquid is clear. This usually takes 30–60 seconds. If any powder clings to the glass, a few more gentle swirls will free it.

Research using mass spectrometry methods to track TB-500 and its metabolites confirms how structurally specific this peptide is — treating it carefully during preparation keeps those structures intact.^[3]

Step 6 — Calculate Your Volume with the Calculator

Now comes the maths. The concentration of your solution depends entirely on how much BAC water you added. If you added 1 mL to a 5 mg vial, each 0.1 mL (10 units on an insulin syringe) contains 0.5 mg. Get this wrong and every subsequent measurement is off. Use our calculator to enter your vial size and water volume — it will instantly tell you exactly how many units to draw for any target amount. No guesswork, no mental arithmetic errors.

Researchers and clinicians reviewing injectable peptide therapies consistently highlight that dosing information for TB-500 remains poorly defined in the literature.^[2] Precision with your reconstitution volume at least ensures your measurements are internally consistent.

Step 7 — Store It Correctly

A reconstituted vial should go straight into the refrigerator (2–8 °C). The benzyl alcohol in BAC water acts as a preservative, typically keeping the solution stable for several weeks when refrigerated. Keep it away from light and never freeze a reconstituted vial — ice crystals can destroy the peptide. Dry, unreconstituted vials can usually be stored at room temperature away from heat and light, or in the freezer for longer-term storage.

One important lab note: peptides like TB-500 can adsorb (stick) to certain plastics and glass surfaces.^[6] Using low-bind syringe tips and glass vials where possible helps ensure the full amount stays in solution rather than clinging to your equipment.

A Quick Reminder

TB-500 is an unapproved compound outside regulatory frameworks for human use.^[4] While preclinical findings are discussed in orthopaedic and sports medicine literature,^[1] rigorous human safety and efficacy data are still lacking.^[2] Everything here is for research and educational purposes only — not medical advice.

Sources

Therapeutic Peptides in Orthopaedics: Applications, Challenges, and Future Directions. — Journal of the American Academy of Orthopaedic Surgeons. Global research & reviews, 2026. PMID 41490200.
Injectable Peptide Therapy: A Primer for Orthopaedic and Sports Medicine Physicians. — The American journal of sports medicine, 2026. PMID 41476424.
Simultaneous quantification of TB-500 and its metabolites in in-vitro experiments and rats by UHPLC-Q-Exactive orbitrap MS/MS and their screening by wound healing activities in-vitro. — Journal of chromatography. B, Analytical technologies in the biomedical and life sciences, 2024. PMID 38382158.
Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance. — Sports medicine (Auckland, N.Z.), 2026. PMID 41966639.
Doping control analysis of TB-500, a synthetic version of an active region of thymosin β₄, in equine urine and plasma by liquid chromatography-mass spectrometry. — Journal of chromatography. A, 2012. PMID 23084823.
Adsorption effects of the doping relevant peptides Insulin Lispro, Synachten, TB-500 and GHRP 5. — Analytical biochemistry, 2017. PMID 28887173.

How to Reconstitute TB-500: A Simple Step-by-Step Guide