How much water do I add to a 5 mg TB-500 vial?

The water amount is your choice, it only changes how strong each mL is. With 2 mL you get 2.5 mg per mL; with more water each unit holds less, which makes small doses easier to measure.

How many units is 1 mg of TB-500?

It depends on the strength of your mix. At 2.5 mg/mL, 1 mg is 40 units. Enter your own vial and water in the calculator to get your number.

How long does mixed TB-500 keep?

Follow the storage line on your product or prescription. Bacteriostatic water itself should be used within 28 days of the first needle, per CDC guidance.

TB-500 dosage calculator

Type in the size of your TB-500 vial, the water amount you added plus your dose. We then show how many units to draw with a U-100 insulin syringe for that dose.

Reference only. Your dose comes from your prescriber or from the label on the product; here we only convert it to units.

vial sizes on the market: 5 mg, 10 mg
status of approval: It is not FDA-approved
example: mixing 5 mg with 2 mL: 2.5 mg/mL strength

The math behind TB-500

Strength comes from dividing the amount in the vial by the water. When a 5 mg vial has 2 mL of water in it, each mL holds 2.5 mg. Take your dose, divide it by that strength for mL, then multiply by 100 to get units on a U-100 syringe.

From that vial, 50 mcg works out to 0.02 mL, or 2 units.

TB-500 unit counts at a glance

Your dose	5 mg vial + 2 mL	10 mg vial + 2 mL
100 mcg	4 units	2 units
150 mcg	6 units	3 units
200 mcg	8 units	4 units
300 mcg	12 units	6 units
400 mcg	16 units	8 units
500 mcg	20 units	10 units
1 mg	40 units	20 units
1.5 mg	60 units	30 units
2 mg	80 units	40 units

Each cell gives the amount to draw on a U-100 syringe, based on that vial and water.

So, is TB-500 FDA-approved?

It has no FDA-approved use in people; it is sold as a research chemical. Because no FDA label exists, no official dose is set. All we do here is convert a dose you already have.

Questions people ask

For a 5 mg TB-500 vial, how much water should you add?

How much water you use is up to you; it only changes the strength of each mL. Using 2 mL gives 2.5 mg per mL; add more water and every unit holds less, which makes measuring small doses easier.

How many units does 1 mg of TB-500 equal?

That depends on how strong your mix is. At 2.5 mg/mL, 1 mg equals 40 units. Type your vial and water into the calculator; it will give you your number.

How long does TB-500 keep once it is mixed?

Check the storage instructions on your product or on your prescription, then follow them. Bacteriostatic water itself should, per CDC guidance, be used within 28 days of that first needle.