How many units is 2 mg of TB-500?

It depends entirely on how much water you added. In a 5 mg vial reconstituted with 2 mL, the concentration is 2.5 mg/mL, so 2 mg is 0.8 mL, which is 80 units on a U-100 insulin syringe. In the same vial with 1 mL of water it is 40 units, and with 3 mL it is 120 units.

How much bacteriostatic water for a 5 mg TB-500 vial?

2 mL is the usual choice. It gives 2.5 mg/mL, which puts the commonly reported range of 0.5 mg to 10 mg between roughly 20 and 400 units. Aim for a draw between about 10 and 50 units, where the barrel is easiest to read, and add or remove water to get there.

How many doses are in a 5 mg vial?

Divide 5 by your dose. At 2 mg that is 2 doses, which at twice weekly is 7 days.

How many units is 2.5 mg of TB-500?

In a 5 mg vial with 2 mL of water, 100 units, a full syringe. With 1 mL of water, 50 units.

TB-500 dosage calculator

TB-500 is dosed in whole milligrams, usually twice a week, with a higher loading phase first.

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25 printable pages: dosing cards for the twelve most-used compounds at three water volumes, titration planners, a vial log, and five pages on what to do when it has already gone wrong.

Dose to units at the usual vial and water

Dose	U-100 units	Draw	Doses per vial	Vial lasts
1 mg	40 units	0.4 mL	5	18 days
2 mg	80 units	0.8 mL	2	7 days
2.5 mg	100 units	1 mL	2	7 days
5 mg	200 units	2 mL	1	4 days
7.5 mg	300 units	3 mL	needs a bigger vial	-
10 mg	400 units	4 mL	needs a bigger vial	-

5 mg vial in 2 mL of bacteriostatic water (2.5 mg/mL), U-100 insulin syringe, twice weekly.

About TB-500

TB-500 is a synthetic fragment of thymosin beta-4, a protein involved in cell migration and tissue repair. It is not an approved medicine and is sold for research use.

Reported protocols usually have two phases: a loading phase of roughly 4 to 10 mg per week split into two injections for four to six weeks, then a lower maintenance dose. A 5 mg vial with 2 mL of water is 2.5 mg/mL, so 2 mg is 0.8 mL, or 80 units. Doses of 5 mg from a 5 mg vial are the whole vial. Because the draws are large, use 1 mL syringes here, and if the calculator warns the draw exceeds the syringe, use less water or split the injection.

The same 5 mg vial at other water volumes

If the draw is awkward to read, change the water, not the dose. The dose stays the same; only the mark moves.

Vial	BAC water	Concentration	Draw	U-100 units	Doses/vial
5 mg	1 mL	5 mg/mL	0.4 mL	40 units	2
5 mg	2 mL	2.5 mg/mL	0.8 mL	80 units	2
5 mg	3 mL	1.67 mg/mL	1.2 mL	120 units	2
10 mg	1 mL	10 mg/mL	0.2 mL	20 units	5
10 mg	2 mL	5 mg/mL	0.4 mL	40 units	5
10 mg	3 mL	3.33 mg/mL	0.6 mL	60 units	5

All rows above assume a 2 mg dose and a standard U-100 insulin syringe, where 100 units = 1 mL.

How long it lasts in the body

Not well characterised in humans. A decay curve is only drawn where a human half-life is documented, so there is none here. Treat any precise figure for TB-500 elsewhere with caution.

Common questions

How many units is 2 mg of TB-500?: It depends entirely on how much water you added. In a 5 mg vial reconstituted with 2 mL, the concentration is 2.5 mg/mL, so 2 mg is 0.8 mL, which is 80 units on a U-100 insulin syringe. In the same vial with 1 mL of water it is 40 units, and with 3 mL it is 120 units.
How much bacteriostatic water for a 5 mg TB-500 vial?: 2 mL is the usual choice. It gives 2.5 mg/mL, which puts the commonly reported range of 0.5 mg to 10 mg between roughly 20 and 400 units. Aim for a draw between about 10 and 50 units, where the barrel is easiest to read, and add or remove water to get there.
How many doses are in a 5 mg vial?: Divide 5 by your dose. At 2 mg that is 2 doses, which at twice weekly is 7 days.
How many units is 2.5 mg of TB-500?: In a 5 mg vial with 2 mL of water, 100 units, a full syringe. With 1 mL of water, 50 units.

IndependentThis site does not sell peptides and is not owned by a vendor.

The maths is openThe formula is on every page and in the methodology. The code is one file with an automated test suite, run before each deploy.

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ReviewedDose ranges and half-lives checked 3 September 2026.

Buying TB-500?

The where to buy page lists the vendors this site uses and what to check first. Peptide Bureau keeps the ranked scorecard.

Where to buyWhat to check before you order Vendor scorecardRanked vendors, at Peptide Bureau Build a full protocolThe stack builder at Peptide Bureau, about two minutes

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mg to units calculator Both directions, any concentration
Bacteriostatic water calculator Pick a volume that lands where you can read it
How to read an insulin syringe U-100 vs U-40, and the 2.5x error
The Protocol Pack Free 25-page printable reference
Where to buy Vendor notes and what to check first
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Before you use these numbers This is a unit-conversion tool. It turns a vial strength and a water volume into a concentration, a draw volume and a syringe mark. It does not tell you what to take, whether to take it, or whether a compound is safe for you. Most compounds listed are sold for laboratory research and are not approved for human use. Nothing here is medical advice. Dosing decisions belong with a licensed clinician who knows your history. Always check the strength printed on your own vial rather than trusting a preset.