TB-500 dosing calculator

CompoundTB-500

Vial

Water

Your dose

1 mg = 1000 mcg.

Your syringe

Draw this much

0.0units

0.400 mL · 5,000 mcg/mL

0 units0.5 mL barrel, U-100 scale50 units

Doses per vial: 5
Per unit: 50 mcg
One vial lasts: 5 days at 1/day

Reference only · Not medical advice

Your draw

Vial10 mg

Water2 mL

Concentration5,000 mcg/mL

Dose2000 mcg

Draw40 units

Syringe0.5 mL, U-100

www.undergroundbiohacking.com · For tracking and calculation purposes only. Not medical advice.

For tracking and calculation purposes only. Not medical advice. Based on a standard U-100 insulin syringe.

How the units are worked out

Your vial holds a fixed amount of peptide. The water you add sets the concentration (how much peptide sits in each millilitre). The concentration then decides how much liquid carries your dose.

Three steps, in order:

Concentration (mcg/mL) = peptide in the vial (mcg) divided by water added (mL).
Volume (mL) = your dose (mcg) divided by the concentration (mcg/mL).
Units to draw = volume (mL) multiplied by 100.

That last step is the syringe, not the peptide. A U-100 insulin syringe is marked so 100 units hold 1 mL, so 0.1 mL reads as 10 units.

A worked example

These are the numbers in the calculator above, worked through: 10 mg + 2 mL = 5,000 mcg/mL. 2000 mcg = 0.40 mL = 40 units on a 0.5 mL syringe.

Change any number in the tool and this line changes with it. The link in your address bar carries the numbers, so you can save it or send it to yourself.

Water and units at a glance

The same dose of TB-500 at different mixes. Every row opens the calculator on that mix.

Vial	Water	Concentration	Units to draw
10 mg	1 mL	10,000 mcg/mL	20 units
10 mg	2 mL	5,000 mcg/mL	40 units
10 mg	3 mL	3,333 mcg/mL	60 units
10 mg	5 mL	2,000 mcg/mL	100 units

Pre-filled numbers are the most-used setups reported by users of public calculators (WPA dosing data, Aug 2026). Not a recommendation.

Mixing and storage

Run the water down the inside wall of the vial and let the powder dissolve on its own. Never shake it. Label the vial with the compound, the total mass, the water you added, the concentration and the date. A sealed freeze-dried vial keeps 12 to 24 months in the fridge at 2 to 8°C. Once mixed with preserved water, such as bacteriostatic water, that drops to roughly 28 days refrigerated. Keep it at the back of the fridge, away from light and away from the door's temperature swings.

Other compounds

Questions

Is TB-500 the same thing as thymosin beta-4?

No. Thymosin beta-4 is a natural protein with 43 amino acids. TB-500 is a lab made copy of just seven of them, positions 17 to 23. That short piece carries a lot of the protein's repair activity in animal work. But it is a different molecule, with different size and behaviour. When you see a human trial of thymosin beta-4, it did not test TB-500. Sellers often treat the two names as interchangeable. They are not.

Has TB-500 ever been tested in a human trial?

No. A search of the published medical literature turns up no clinical trial of TB-500 in people. What exists is animal and laboratory work: rats with cut tendons, mice with skin wounds, cell cultures, and horses used in doping research. The FDA says the same thing in plainer words. It has not identified any human exposure data for products containing this fragment. So every claim about what it does in a person is an extrapolation.

Does the human dry eye research count as evidence for TB-500?

Not directly. Those trials used thymosin beta-4 eye drops, the full protein, on the surface of the eye. One phase 2 trial in severe dry eye showed clear improvement. Another missed both of its main endpoints, though it improved several secondary ones. Neither tested TB-500, and neither tested an injection. Carrying an eye drop result across to an injected fragment of a different size is not something the data supports.

Is TB-500 banned in sport?

Yes. A 2026 review in a sports medicine journal states that thymosin beta-4 and TB-500 both remain banned substances in sport. Anti doping labs have built tests aimed straight at it. Published methods detect the acetylated LKKTETQ peptide and its breakdown products in urine and plasma at very low levels. It has also been detected in horses after it was given to them. If you compete under an anti doping code, using it risks a sanction.

Can a pharmacy legally compound TB-500?

No. FDA has placed thymosin beta-4 fragment, named on that page as TB-500, in category 2 of the bulk drug substances lists. Category 2 covers substances FDA identified as potentially presenting significant safety risks. The stated concerns are immunogenicity and peptide related impurities, plus the absence of any human exposure data. TB-500 is not an approved drug in the United States. An advisory committee vote is advice, not law, and changes nothing.

What should I ask a doctor before considering it?

Ask what human evidence exists for this exact molecule, and expect the honest answer to be none. Ask what is actually in the vial, since no approved manufacturer makes it. Ask about immune reactions, because that is the risk FDA names first. Ask about your own cancer history. The parent protein sits at high levels in many tumours, and nobody has tested the fragment in people.