TB-500 Dosage Calculator
Enter the amount in your TB-500 vial, the volume it is in, and the dose you want expressed in syringe units. This page computes the arithmetic of those values — concentration, the volume to draw, insulin-syringe units, and doses per vial. It is not a dosing recommendation.
- Concentration
- 2.5 mg/mL
- Draw volume
- 0.2 mL
- Doses per vial
- 10
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The values above are pre-filled as a worked example so the page loads with numbers to read. They are not a recommended vial size, diluent volume, or dose. Change any field to compute your own.
TB-500 at a glance
- Also known as
- thymosin beta-4 fragment 17–23 · Ac-LKKTETQ · Tβ4 (17–23)
- Compound class
- Synthetic research peptide
- Supplied as
- Lyophilized (freeze-dried) powder — dissolved in a diluent before any volume can be drawn
- Vial strengths
- 2 mg lyophilized vial — commonly supplied · 5 mg lyophilized vial — commonly supplied · 10 mg lyophilized vial — commonly supplied
- Regulatory status
- There is no FDA-approved product containing this compound in any form, and it is not an approved medicine in the United States. Material sold for laboratory or research use is not labeled or regulated for human use, and no approved labeling defines a vial strength, a diluent, or a concentration for it.
What TB-500 is
TB-500 is a synthetic seven-amino-acid peptide corresponding to residues 17–23 of thymosin β4 — the sequence LKKTETQ, which is that protein's actin-binding region — and is commonly supplied in an N-terminally acetylated form.
It is not the same molecule as full-length thymosin β4, which is a 43-amino-acid protein; the two are often referred to interchangeably, and a mass printed on a vial refers to whichever molecule that vial actually contains.
There is no FDA-approved TB-500 product, so no approved labeling defines a vial strength or a concentration; material supplied as a lyophilized powder has to be dissolved before any volume can be drawn.
This page's calculator computes concentration, the volume to draw, and the equivalent insulin-syringe units from the mass and volume you enter.
Load a vial strength into the calculator
Each link re-runs the calculator above with that strength's numbers already entered.
Rows marked FDA-approved are strengths stated in approved labeling. Rows marked commonly supplied are vial sizes that compounded and research presentations are commonly supplied in; no approved labeling defines those, and what a given vial contains is only what is printed on that vial.
TB-500 calculator questions
How many units is a 500 mcg dose of TB-500?
With the example values on this page — 5 mg in 2 mL of bacteriostatic water — the vial works out to 2.5 mg/mL, so a 500 mcg dose is 0.2 mL, which reads as 20 units on a U-100 insulin syringe. Change any field in the calculator above and the computed units change with it.
What does a 5 mg vial of TB-500 come out to with different amounts of bacteriostatic water?
Concentration is the mass in the vial divided by the volume it is in, so changing only the volume changes every downstream number: 1 mL computes to 5 mg/mL, making a 500 mcg dose 0.1 mL (10 units); 2 mL computes to 2.5 mg/mL, making a 500 mcg dose 0.2 mL (20 units); 4 mL computes to 1.25 mg/mL, making a 500 mcg dose 0.4 mL (40 units). Each figure is arithmetic on the two values stated, not a statement that any of those volumes is the one to use.
How many 500 mcg doses are in a 5 mg vial of TB-500?
Dividing 5 mg by 500 mcg computes to 10 full doses. Only whole doses are counted — any remainder smaller than a full dose is left out of that figure. Different vial contents or a different dose produce a different count; enter yours in the calculator above.
What concentration is 5 mg of TB-500 in 2 mL?
5 mg in 2 mL computes to 2.5 mg/mL. From that concentration, the volume holding a 500 mcg dose is 0.2 mL, or 20 units on a U-100 syringe. This page reports that division; it does not evaluate the numbers you put into it.
How much bacteriostatic water do I add to a vial of TB-500?
That volume is an input to this calculator, not an output of it — this page does not pick a volume for you and nothing here says which one to use. What it can tell you is what each choice computes to: 5 mg with 1 mL works out to 5 mg/mL, and the same 5 mg with 4 mL works out to 1.25 mg/mL. The mass in the vial never changes; only the concentration and the volume you would draw do.