All peptides calculator
TB-500 is a synthetic peptide based on a short active region of thymosin beta-4, a protein found throughout the body. It has been studied in animals for tissue repair, but it has never been approved by the FDA for any use.
The FDA had listed the thymosin beta-4 fragment among bulk substances that may present significant safety risks in compounding, citing a risk of immunogenicity. In April 2026 it was removed from that list after the nomination was withdrawn (FDA). In July 2026, the FDA's Pharmacy Compounding Advisory Committee voted 8 to 6, with one abstention, to recommend adding TB-500 to the list of substances pharmacies can compound with, against the advice of FDA staff (AJMC). The FDA still has to accept that recommendation and complete rulemaking before compounding is allowed.
The WADA prohibited list names thymosin beta-4 and its derivatives, including TB-500, as banned at all times.
Most TB-500 sold online is labelled "for research use only." We don't recommend buying peptides that way. This page doesn't suggest a dose. It only converts an amount you've been given into syringe units.
Step 1: Enter your vial size in mg. Use the amount printed on the vial. If yours isn't one of the presets, type it in.
Step 2: Enter the bacteriostatic water you added. The calculator divides the mg by the mL to get your concentration.
Step 3: Choose your syringe. TB-500 amounts are usually written in milligrams, so the volume tends to be larger than for microgram peptides. A 1 mL (100 unit) syringe fits every preset at the default concentration.
Step 4: Enter the amount in mg. The presets are shortcuts, not recommendations. If you were given a number in mcg, switch the unit to mcg and the calculator converts it.
With the defaults shown, a 5 mg vial mixed with 2 mL is 2.5 mg/mL, so 1 mg is 0.4 mL, or 40 units. Mix the same vial with 1 mL and 1 mg is 20 units.
TB-500 is often sold pre-blended with BPC-157 in one vial. Tick Blend next to the vial amount, enter each peptide with its mg, and use Dose Based On to pick which one your amount refers to. The result shows how much of each peptide you're drawing, so you can see the BPC-157 that comes along with your TB-500.
100 units on a U-100 syringe is always 1 mL. How many milligrams that holds depends on your concentration.
2.5 mg/mL is a 5 mg vial in 2 mL, 5 mg/mL is a 5 mg vial in 1 mL or a 10 mg vial in 2 mL, and 10 mg/mL is a 10 mg vial in 1 mL. The formula is: units = amount in mg ÷ concentration in mg/mL × 100.
If your result is more than your syringe holds, the calculator will warn you. Don't split a draw across two syringes by eye. Our peptide syringe units guide explains how each syringe size is marked, the general peptide calculator covers other peptides, and PeptideKit can keep a log of every dose.
Divide the vial's mg by the mL of water added to get the concentration in mg/mL. Divide the amount you need by that concentration to get mL, then multiply by 100 for units on a U-100 syringe.
At 2.5 mg/mL (5 mg in 2 mL), 2 mg is 80 units. At 5 mg/mL, it's 40 units. At 10 mg/mL, it's 20 units. This is a conversion example, not a suggested dose.
10 units is 0.1 mL. At 2.5 mg/mL that's 0.25 mg, at 5 mg/mL it's 0.5 mg, and at 10 mg/mL it's 1 mg.
There isn't an FDA-reviewed one, because TB-500 isn't an approved drug. A calculator can't fill that gap. Talk to a licensed clinician before using it.
Not exactly. Thymosin beta-4 is a 43 amino acid protein your body makes. TB-500 is a much shorter synthetic peptide based on one part of it. They aren't interchangeable, and a vial of one isn't a vial of the other.
Always consult with qualified healthcare professionals before starting any peptide therapy protocol. This information is for educational purposes only and does not constitute medical advice.
TB-500 Dosage Calculator
Enter your TB-500 vial size, how much bacteriostatic water was added, and the amount you were told to take in mg. The calculator shows how many units to draw on a U-100 insulin syringe.
Peptide Amount in Vial
BAC Water
Syringe
Target Dose
Use the dose on your prescription. Presets are shortcuts, not recommendations.
Unit Rounding
Round the result to a whole or half unit mark you can read on your syringe.
Peptide Amount (Total in Vial)
Desired Concentration
Read This First: TB-500 Isn't an Approved Drug
TB-500 is a synthetic peptide based on a short active region of thymosin beta-4, a protein found throughout the body. It has been studied in animals for tissue repair, but it has never been approved by the FDA for any use.
The FDA had listed the thymosin beta-4 fragment among bulk substances that may present significant safety risks in compounding, citing a risk of immunogenicity. In April 2026 it was removed from that list after the nomination was withdrawn (FDA). In July 2026, the FDA's Pharmacy Compounding Advisory Committee voted 8 to 6, with one abstention, to recommend adding TB-500 to the list of substances pharmacies can compound with, against the advice of FDA staff (AJMC). The FDA still has to accept that recommendation and complete rulemaking before compounding is allowed.
The WADA prohibited list names thymosin beta-4 and its derivatives, including TB-500, as banned at all times.
Most TB-500 sold online is labelled "for research use only." We don't recommend buying peptides that way. This page doesn't suggest a dose. It only converts an amount you've been given into syringe units.
How to Use the TB-500 Dosage Calculator
Step 1: Enter your vial size in mg. Use the amount printed on the vial. If yours isn't one of the presets, type it in.
Step 2: Enter the bacteriostatic water you added. The calculator divides the mg by the mL to get your concentration.
Step 3: Choose your syringe. TB-500 amounts are usually written in milligrams, so the volume tends to be larger than for microgram peptides. A 1 mL (100 unit) syringe fits every preset at the default concentration.
Step 4: Enter the amount in mg. The presets are shortcuts, not recommendations. If you were given a number in mcg, switch the unit to mcg and the calculator converts it.
With the defaults shown, a 5 mg vial mixed with 2 mL is 2.5 mg/mL, so 1 mg is 0.4 mL, or 40 units. Mix the same vial with 1 mL and 1 mg is 20 units.
Using a TB-500 and BPC-157 Blend
TB-500 is often sold pre-blended with BPC-157 in one vial. Tick Blend next to the vial amount, enter each peptide with its mg, and use Dose Based On to pick which one your amount refers to. The result shows how much of each peptide you're drawing, so you can see the BPC-157 that comes along with your TB-500.
TB-500 Units to mg Conversion Table
100 units on a U-100 syringe is always 1 mL. How many milligrams that holds depends on your concentration.
| Syringe units | Volume | At 2.5 mg/mL | At 5 mg/mL | At 10 mg/mL |
|---|---|---|---|---|
| 5 units | 0.05 mL | 0.125 mg | 0.25 mg | 0.5 mg |
| 10 units | 0.1 mL | 0.25 mg | 0.5 mg | 1 mg |
| 20 units | 0.2 mL | 0.5 mg | 1 mg | 2 mg |
| 25 units | 0.25 mL | 0.625 mg | 1.25 mg | 2.5 mg |
| 40 units | 0.4 mL | 1 mg | 2 mg | 4 mg |
| 50 units | 0.5 mL | 1.25 mg | 2.5 mg | 5 mg |
| 100 units | 1 mL | 2.5 mg | 5 mg | 10 mg |
If your result is more than your syringe holds, the calculator will warn you. Don't split a draw across two syringes by eye. Our peptide syringe units guide explains how each syringe size is marked, the general peptide calculator covers other peptides, and PeptideKit can keep a log of every dose.
Frequently Asked Questions
How do I calculate TB-500 units?
Divide the vial's mg by the mL of water added to get the concentration in mg/mL. Divide the amount you need by that concentration to get mL, then multiply by 100 for units on a U-100 syringe.
How many units is 2 mg of TB-500?
At 2.5 mg/mL (5 mg in 2 mL), 2 mg is 80 units. At 5 mg/mL, it's 40 units. At 10 mg/mL, it's 20 units. This is a conversion example, not a suggested dose.
How much TB-500 is in 10 units?
10 units is 0.1 mL. At 2.5 mg/mL that's 0.25 mg, at 5 mg/mL it's 0.5 mg, and at 10 mg/mL it's 1 mg.
What is the right TB-500 dosage?
There isn't an FDA-reviewed one, because TB-500 isn't an approved drug. A calculator can't fill that gap. Talk to a licensed clinician before using it.
Is TB-500 the same as thymosin beta-4?
Not exactly. Thymosin beta-4 is a 43 amino acid protein your body makes. TB-500 is a much shorter synthetic peptide based on one part of it. They aren't interchangeable, and a vial of one isn't a vial of the other.
Always consult with qualified healthcare professionals before starting any peptide therapy protocol. This information is for educational purposes only and does not constitute medical advice.