TB-500 Reconstitution Protocol: Concentration Math & Volume Calculator

This is a TB-500-specific reconstitution reference: the exact bacteriostatic-water volumes, the resulting concentrations, and the arithmetic for converting a target research quantity into a syringe volume. It is reconstitution and measurement math for laboratory handling, not a human-dosing recommendation.

ScopeThis page handles the numbers for the OzPeps TB-500 10mg vial →. For the generic step-by-step reconstitution procedure (warming the vial, wiping stoppers, injecting down the glass wall, swirling), see the peptide reconstitution & storage guide →; those steps are identical for every peptide and are not repeated here. For TB-500's biology, mechanism, and the research base, see the TB-500 research guide →.

TB-500 (the 43-amino-acid Thymosin Beta-4 analogue) has one practical handling quirk relevant to this page: its longer peptide chain can dissolve more slowly than short peptides; gentle palm warming of the vial (never heat) aids dissolution. Everything else below is arithmetic.

Reconstitution concentration depends only on two numbers: the mass of peptide in the vial and the volume of bacteriostatic water you add. The relationship is:

Concentration = peptide mass ÷ water volumeFor a 10mg TB-500 vial, adding 2 mL of bacteriostatic water gives 10 mg ÷ 2 mL = 5 mg/mL. The peptide mass never changes; only the volume of water you choose changes the concentration.

Because 1 mg = 1,000 mcg, a 10mg vial contains 10,000 mcg total. Working in mcg is often easier when computing small draw volumes, so both units are shown in the tables below.

Adding more water makes a weaker (more dilute) solution that is easier to measure in small increments; adding less water makes a stronger solution that needs less volume per draw. The total peptide available is identical either way; dilution does not change how much TB-500 is in the vial.

Resulting concentration for the OzPeps TB-500 10mg vial (10mg = 10,000 mcg total) at common bacteriostatic-water volumes. The right-hand column shows how much peptide sits in a 0.1 mL draw, which equals 10 units on a U-100 insulin syringe (see the conversion section below).

Each row is just 10,000 mcg divided by the water volume: 10,000 ÷ 1 = 10,000; 10,000 ÷ 2 = 5,000; 10,000 ÷ 2.5 = 4,000; 10,000 ÷ 5 = 2,000 mcg/mL. A 2 mL reconstitution (5 mg/mL) is the most common choice for a 10mg vial because it produces round, easy-to-measure draw volumes.

Why TB-500 is usually given more water than tiny peptidesTB-500's long chain dissolves more readily into a slightly larger solvent volume, and a 2 mL fill keeps draw volumes large enough to measure accurately on an insulin syringe. There is no single "correct" volume; pick the concentration that makes your target draw land on a clean syringe graduation.

Research draws are almost always measured on a U-100 insulin syringe, where the barrel is graduated in "units" (IU) rather than millilitres. The conversion is fixed and has nothing to do with the peptide:

U-100 syringe scale100 units (IU) = 1 mL. Therefore 1 IU = 0.01 mL, 10 IU = 0.1 mL, 50 IU = 0.5 mL, and 100 IU = 1.0 mL. To turn any volume in mL into units, multiply by 100.

Note that "units" here are a volume marking on the syringe; they are not a measure of peptide mass. The mass in any draw depends entirely on the concentration set during reconstitution (the table above). A U-100 insulin syringe is included in OzPeps' research supplies →.

To find the volume that contains a target quantity of peptide, divide the target by the concentration:

Volume (mL) = target quantity (mcg) ÷ concentration (mcg/mL)Then multiply the result by 100 to read it in insulin units. Keep both numbers in mcg (or both in mg) so the units cancel.

The four worked examples below all use the OzPeps TB-500 10mg vial. Each is shown with a forward check (volume × concentration should return the target).

Example 1, step by step. Vial reconstituted with 2 mL → 5,000 mcg/mL. Target 2,000 mcg: 2,000 ÷ 5,000 = 0.40 mL = 40 IU. Check: 0.40 mL × 5,000 mcg/mL = 2,000 mcg. ✓

Example 2. Same 5,000 mcg/mL solution. Target 500 mcg: 500 ÷ 5,000 = 0.10 mL = 10 IU. Check: 0.10 mL × 5,000 = 500 mcg. ✓

Example 3. Vial reconstituted with 1 mL → 10,000 mcg/mL. Target 2,500 mcg: 2,500 ÷ 10,000 = 0.25 mL = 25 IU. Check: 0.25 mL × 10,000 = 2,500 mcg. ✓

Example 4. Vial reconstituted with 2.5 mL → 4,000 mcg/mL. Target 1,000 mcg: 1,000 ÷ 4,000 = 0.25 mL = 25 IU. Check: 0.25 mL × 4,000 = 1,000 mcg. ✓

The same equation works for any vial size or target; OzPeps also provides a reconstitution calculator → that does the arithmetic for you. These quantities are measurement examples for research handling, not dosing recommendations.

Total peptide in the vial (10mg) divided by the per-draw quantity tells you how many measured draws a single vial contains; this is independent of how much water you added, because total mass is fixed.

Each figure is 10,000 mcg divided by the per-draw mcg: 10,000 ÷ 500 = 20; 10,000 ÷ 1,000 = 10; 10,000 ÷ 2,000 = 5; 10,000 ÷ 2,500 = 4. This helps plan how much bacteriostatic water to buy; a 2 mL fill uses well under one 3 mL vial of water, while several vials reconstituted at once may justify the 10 mL size.

OzPeps stocks bacteriostatic water in 3 mL (single-vial reconstitution) and 10 mL (multi-vial) sizes.

TB-500's storage requirements differ sharply between its dry (lyophilised) form and its reconstituted (in-solution) form. These are standard peptide-handling facts and apply to TB-500 as to other lyophilised peptides:

• Use bacteriostatic, not plain sterile, water. The 0.9% benzyl alcohol preservative is what extends a reconstituted multi-draw vial's usable life to roughly four weeks refrigerated; plain sterile water has no preservative.
• Refrigerate the reconstituted solution at 2–8°C and keep it away from light.
• Do not freeze the reconstituted solution for routine storage; freeze-thaw cycling stresses peptide structure. If long-term storage of a solution is unavoidable, aliquot into single-use volumes first.
• Let a frozen lyophilised vial reach room temperature before opening so condensation does not form on the powder.

For the full generic storage rationale (photodegradation of aromatic residues, freeze-thaw handling, the benzyl-alcohol mechanism), see the reconstitution & storage guide →; this page lists only the TB-500-relevant figures.

How much bacteriostatic water do I add to a TB-500 10mg vial?

There is no single required volume; the choice sets the concentration. Adding 1 mL gives 10 mg/mL, 2 mL gives 5 mg/mL, 2.5 mL gives 4 mg/mL, and 5 mL gives 2 mg/mL. A 2 mL fill (5 mg/mL) is the most common because it produces clean draw volumes on an insulin syringe.

What is the mg/mL of a 10mg TB-500 vial?

It depends on the water volume you add, because concentration = mass ÷ volume. For 10mg: 1 mL → 10 mg/mL; 2 mL → 5 mg/mL; 2.5 mL → 4 mg/mL; 5 mL → 2 mg/mL.

How do I work out the volume for a target quantity?

Divide the target (in mcg) by the concentration (in mcg/mL), then multiply by 100 for insulin units. Example: from a 5,000 mcg/mL solution, a 2,000 mcg target = 2,000 ÷ 5,000 = 0.4 mL = 40 IU. These are measurement examples for research handling, not dose advice.

What do the units on an insulin syringe mean?

On a U-100 syringe, 100 units = 1 mL, so 10 units = 0.1 mL. The units measure volume, not peptide mass; the mass per unit depends on the concentration you reconstituted at.

Does TB-500 reconstitute differently from other peptides?

The procedure is the same, but TB-500's 43-amino-acid chain can dissolve more slowly; gentle palm warming of the vial (never heat) aids dissolution. The full step-by-step procedure is in the reconstitution guide; TB-500's biology is in the TB-500 research guide.

How long does reconstituted TB-500 last?

Stored refrigerated at 2–8°C in bacteriostatic water, a reconstituted solution is typically used within about 28 days, the window set by the benzyl-alcohol preservative. The dry lyophilised powder is stable at −20°C for 24+ months before reconstitution.

OzPeps supplies the research-grade TB-500 10mg vial → Australia-wide, with bacteriostatic water available in 3 mL and 10 mL sizes and U-100 insulin syringes → in the supplies section.

Related: TB-500 research guide (mechanism & studies) → · peptide reconstitution & storage guide → · reconstitution calculator →

This page presents reconstitution and measurement arithmetic for laboratory research handling only. It is not a dosing recommendation and contains no medical advice. All TB-500 supplied by OzPeps is for in-vitro research use only, is not for human or animal consumption, and is not a TGA-approved therapeutic good. Researchers are responsible for compliance with all applicable regulations.