TB-500 Dosage Calculator
TB-500 is a short synthetic fragment of thymosin beta-4. It is unusual among research peptides because the doses discussed online are in whole milligrams, not micrograms, which means a 5 mg vial can be gone in two draws and a full 1 mL syringe may not be enough.
This page shows the reconstitution math for 2 mg, 5 mg and 10 mg TB-500 vials and flags the case where a milligram dose does not fit the syringe you own.
Forum protocols onlyThe ranges you see online come from forums and animal-study extrapolation. No human dose-finding trial exists. · Reviewed by the FormBlends Editorial Standards Team · 2026-09-03
Forum protocols onlyNo FDA label and no human trial of the fragment. Human data exist only for full-length thymosin beta-4 given intravenously or as eye drops.
Enter your dose to see the units to draw, the volume in mL, and how long the vial lasts.
FDA compounding status (2026-07-23): Not lawfully compoundable yet. Same path as BPC-157: withdrawn from Category 2 in April 2026; PCAC recommended 8-6-1 on 07/23/2026; no rule yet.. Full status table and sources
What the TB-500 dose evidence actually is
No FDA label and no human trial of the fragment. Human data exist only for full-length thymosin beta-4 given intravenously or as eye drops.
There is no human dosing study of TB-500 itself. The human trials that exist used full-length thymosin beta-4, either intravenously in a phase 1 safety study at doses far above anything sold as TB-500, or as RGN-259 eye drops. A trial of the fragment was registered in 2026 and is recruiting, so that may change.
The 2 to 2.5 mg twice-weekly loading figure and the 2 mg weekly maintenance figure you will read elsewhere come from forums. They are repeated often enough to look authoritative. They are not. Enter the dose you were given and treat those numbers as background.
TB-500 units at each water volume
The table uses a 5 mg vial. Each cell is the draw on a U-100 insulin syringe for that dose at that water volume. Cells above 100 units do not fit a 1 mL syringe; cells below 10 units sit in the part of a 1 mL barrel where measurement error rises, and a 0.5 mL or 0.3 mL syringe reads them better.
| Dose | 5 mg + 1 mL5 mg/mL | 5 mg + 2 mL2.5 mg/mL | 5 mg + 3 mL1.667 mg/mL | 5 mg + 5 mL1 mg/mL |
|---|---|---|---|---|
| 0.5 mg | 10 units | 20 units | 30 units | 50 units |
| 1 mg | 20 units | 40 units | 60 units | 100 units |
| 2 mg | 40 units | 80 units | 120 (does not fit) | 200 (does not fit) |
| 5 mg | 100 units | 200 (does not fit) | 300 (does not fit) | 500 (does not fit) |
The doses in this table are round numbers chosen to show the arithmetic. They are not recommendations; no label or human dose-finding trial exists for TB-500.
Mixing TB-500
Because the doses are large, use less water. Five milligrams in 1 mL gives 5 mg per mL, so 2.5 mg is 50 units, which fits a 0.5 mL or 1 mL syringe. The same 5 mg in 2 mL gives 2.5 mg per mL and 2.5 mg becomes 100 units, the entire barrel of a 1 mL syringe.
If your draw comes out above 100 units the calculator will tell you it does not fit. The fix is less water in the vial, not two injections.
Storing TB-500 after mixing
Refrigerate after mixing. A 5 mg vial at 2.5 mg per dose is two doses, so the vial is finished long before any storage limit matters. A 10 mg vial at 2 mg weekly lasts five weeks, which is past the 28-day multiple-dose ceiling; the calculator flags that.
TB-500 calculator questions
How much bac water for 5 mg TB-500?
One millilitre is the practical choice for milligram doses. It gives 5 mg per mL, so 2.5 mg is 50 units and 2 mg is 40 units. Two millilitres makes 2.5 mg a full 100-unit draw.
How many units is 2 mg of TB-500?
Forty units at 5 mg per mL (5 mg in 1 mL). Eighty units at 2.5 mg per mL (5 mg in 2 mL). Twenty units at 10 mg per mL (10 mg in 1 mL).
Does the BPC-157 and TB-500 blend change the math?
Only in how you read the result. The units depend on total milligrams in the vial and total water. Switch on the blend option and the calculator splits each draw into the milligrams of each component.
Is there a human study of TB-500 dosing?
Not yet. Human data cover full-length thymosin beta-4, not the fragment. A trial of the fragment registered in 2026 is recruiting.
Sources
TB-500 guide
Evidence, mechanism, side effects and regulatory status.
TB-500 through FormBlends
Provider review, licensed pharmacy, labelled concentration.
The full peptide calculator
All peptides, pre-mixed vials, blends, mistakes and concentration changes.
Free downloads built from this calculator's math
Peptide Dosing and Reconstitution Chart 2026
20 pages, 12 peptides, every vial size, units at five water volumes, printable vial labels. PDF.
Bacteriostatic Water Cheat Sheet
How much to add, what one unit holds, the 28-day rule stated correctly, four mistakes to avoid. PDF.
28-Day GLP-1 Injection Tracker
Dose, units drawn, site, weight, side effects and the vial counting down. PDF and spreadsheet.
Other peptide calculators
Arithmetic only. This page converts the dose you enter into units and millilitres. It does not recommend a dose. TB-500 is not an FDA-approved drug and no human dose-finding trial exists; any dose you enter should come from a prescriber. FormBlends connects patients with licensed providers and pharmacies and does not prescribe or dispense.
