TB-500 dosage calculator

TB-500 is quoted in milligrams far more often than in micrograms, which is where most of the arithmetic errors come from. Enter either, as the toggle converts, and this returns the concentration, the volume and the units on a U-100 syringe. The dose comes from the prescriber; the figure the page opens with is an arbitrary placeholder, not a dose.

Peptide

Vial size (mg)

Bacteriostatic water (ml)

Desired dose

The dose your prescriber set. The opening figure is an example for the arithmetic, not a dose.

Syringe or pen

Amounts are usually written in milligrams rather than micrograms: 1000mcg is 1mg, the same quantity entered two ways. The opening 100mcg is an arbitrary placeholder, not a dose: the dose comes from the prescriber.

Draw to

4units

on a U-100 insulin syringe (0.04 ml)

Concentration: 2.5 mg/ml; 2500 mcg/ml
Volume to draw: 0.04 ml
Doses per vial: 50
Syringe capacity: 100 units

How this is calculated

concentration (mg/ml)  = vial mg / water ml            = 5 / 2 = 2.5
concentration (mcg/ml) = concentration mg/ml x 1000    = 2500
volume to draw (ml)    = dose mcg / concentration mcg  = 100 / 2500 = 0.04
insulin units          = volume ml x 100               = 0.04 x 100 = 4
doses per vial         = floor(water ml / volume ml)   = floor(2 / 0.04) = 50

100 units = 1 ml on every U-100 insulin syringe. Barrel size changes how much it holds,
never what a unit means.

How TB-500 is supplied, and the unit trap

TB-500 is a lyophilised powder in sealed vials, usually 2mg, 5mg or 10mg. Unlike most research peptides, amounts for it are usually written in milligrams rather than micrograms, and that difference in convention is the single most common cause of error on a calculator like this one. 1mg and 1000mcg are the same quantity written two ways, and a milligram figure entered into a field expecting micrograms is a thousandfold mistake.

The figure in the amount field when the page opens, 100mcg, is an arbitrary placeholder chosen so the arithmetic is easy to follow. It is not a dose and is not based on any amount people use. The dose comes from the prescriber: replace the placeholder with the amount on your prescription.

The calculator above carries an explicit mcg/mg toggle for that reason, and shows the concentration in both units beneath the result. If the units figure it returns looks implausible against the barrel in front of you, the unit toggle is the first thing to check.

Reconstitution volumes

Because the quantities involved are larger than most peptides, TB-500 is usually reconstituted in 2ml or more, and a 5mg vial in 2ml gives 2500 mcg/ml. At that concentration each milligram occupies 0.4ml, or 40 units, so a quantity of a milligram or more quickly outgrows a 0.3ml or 0.5ml barrel and needs a 1ml syringe. The alternative is a smaller volume of water: the same 5mg vial in 1ml doubles the concentration and halves the units.

This is the case where the syringe-capacity notice earns its place. The calculator does not quietly rescale anything when a figure exceeds the barrel; it states the figure, names the barrel it will not fit, and leaves the two real options: a larger syringe, or a more concentrated solution.

Storage and stability, in general terms

Sealed vials of lyophilised powder keep well when cool, dry and dark. Once liquid, the solution needs refrigeration and has a much shorter life, measured in weeks; heat, light and shaking all shorten it further. Bacteriostatic water, with its benzyl alcohol preservative, is what permits a vial to be entered more than once. Plain sterile water does not, and is a single-use diluent.

The usable window for any specific vial comes from the supplier, not from a general rule, and it varies with peptide, diluent and storage. This page does not offer a figure for it.

About TB-500

This calculator does arithmetic only. For what TB-500 is, what the research shows, its side effects and its US status under the interim HHS policy, see our TB-500 peptide page.

Frequently asked questions

Is TB-500 measured in mg or mcg?

Both, and that is the problem. Amounts for it are usually written in milligrams, while most peptide calculators expect micrograms. 1mg is 1000mcg. The toggle above converts, and the concentration is shown in both units so a thousandfold slip is visible rather than silent.

How many units is a milligram of TB-500?

From a 5mg vial in 2ml (2500 mcg/ml), each milligram is 0.4ml, which is 40 units on a U-100 syringe. From the same vial in 1ml it is 20 units. Scale that by the amount on your prescription, which comes from the prescriber; the concentration decides the rest.

Why does my figure exceed the syringe?

Because the quantity is large relative to the concentration. The two ways out are a larger barrel — a 1ml insulin syringe holds 100 units — or less bacteriostatic water, which raises the concentration so the same quantity occupies fewer units. The calculator flags the case rather than hiding it.

Can I reconstitute a 10mg vial in 5ml?

Arithmetically yes: that is 2000 mcg/ml, and the calculator will show what any quantity comes to at that concentration. Whether a larger volume is sensible for a given vial depends on how long the solution will be kept and what the supplier says about it, neither of which this page can answer.

Is TB-500 an approved medicine?

No. It is not FDA-approved for the uses described online and is not a licensed medicine in the UK. This page does arithmetic on figures you enter and makes no claim that any use of it is appropriate or lawful where you are.

Before you use this

This tool performs arithmetic only. It does not recommend a dose, a frequency, a duration or a supplier. Many peptides discussed online are not approved by the FDA for the uses people describe. Compounded medicines are supplied on prescription and should be prepared exactly as your pharmacy instructs. Talk to a prescriber or pharmacist before preparing or administering anything.

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