TB-500 reconstitution calculator
How many units of a reconstituted tb-500 vial make up the dose you want — and how much bacteriostatic water to add to land on a round number. Same code as the TherapyLog app, no account needed.
TB-500 sits between the two extremes: dosed in milligrams like a GLP-1 but only two to two and a half at a time, and injected once or twice a week rather than daily. At a 5 mg vial in 2 ml of bacteriostatic water, a 2.5 mg dose is one millilitre — a full U-100 syringe — and the vial holds exactly two of them.
That "exactly two" is the thing to plan around. A vial that yields a whole number of doses wastes nothing and needs no partial draws; one that yields 2.3 doses leaves a remainder you will either discard or stretch. The reverse solver on this page exists for that question: tell it the dose you want and the units you want to draw, and it works backwards to the diluent volume.
TB-500 milligrams to insulin units
Computed for a 5 mg vial reconstituted in 2 ml of bacteriostatic water, which gives 2.50 mg per ml (2,500 mcg/ml), read off a U-100 syringe. The steps are the milligram-scale amounts described in the literature and community practice (2–2.5 mg per injection) — they are what the numbers are indexed to, not advice about which one applies to anyone. Change the vial or the water above and every figure moves; the calculator is the authority, this table is the common case.
| TB-500 dose | Volume to draw | On a U-100 syringe |
|---|---|---|
| 2 mg | 0.8 ml | 80 units |
| 2.5 mg | 1 ml | 100 units |
Why tb-500 is reconstituted the way it is
TB-500 is a synthetic fragment of thymosin beta-4, a peptide present in most cells, and like BPC-157 it is a research compound with no human approval. Its modelled half-life of about two days is an estimate; that is the reason its schedules are weekly or twice weekly where BPC-157's are daily.
Because it is systemically acting rather than applied near a site, the whole dose has to be drawn and injected at once, which is why the barrel size matters here in a way it does not for a microgram-scale peptide.
What the app knows about TB-500
Generated from the same entry the app's encyclopedia reads, so this page and the app cannot disagree about it.
- Also known as
- Thymosin Beta-4
- Class
- Peptides
- Modelled half-life
- 2 days — estimated half-life, limited human PK data
- Time to peak
- 4 h
- Formulation
- Aqueous (reconstituted powder)
- Regulatory status
- Research compound — no FDA approval. Not for human use label.
- Monitoring panel
- No specific labs. General health panel annually.
- Before mixing
- Sealed powder tolerates room temperature in transit, but keep it refrigerated at 2–8 °C (36–46 °F) for anything beyond a few weeks, or frozen for months. Keep it dark — the carton it shipped in is doing a job.
- After mixing
- Once reconstituted with bacteriostatic water: refrigerate at 2–8 °C and use within about 28 days. The benzyl alcohol in bacteriostatic water is what buys that window — plain sterile water has no preservative, so a vial mixed with it should be treated as one sitting only. Kits are usually ten vials: only the one you mixed is on that 28-day clock — the sealed ones keep their own, much longer shelf life, so store them as powder, not as solution.
- What ruins it
- Do not freeze a reconstituted vial. Repeated freeze–thaw is one of the more reliable ways to degrade a peptide.
- Handling caveat
- General handling practice for this formulation. Your supplier’s own insert or COA overrides anything here.
Dosing rows from that entry
Off-label or community practice These are the schedules the entry records, reproduced so you can see what the milligram figures above are indexed to. Which one applies to a particular person is a prescribing decision, and this page does not make it.
| Label | Amount | Route and frequency |
|---|---|---|
| Loading | 2-2.5mg twice weekly | SubQ or IM |
| Maintenance | 2-2.5mg once weekly | SubQ |
How the math works
volume to draw = dose (mcg) ÷ 2,500 mcg/ml
units (U-100) = volume to draw (ml) × 100
The rules built into the calculator: a practical draw lands on a half-unit and is at least two units; U-100 means a hundred units per millilitre, so 0.1 ml is 10 units on any U-100 syringe regardless of its barrel size; and a draw that exceeds the barrel is flagged rather than silently split across injections.
Questions people ask about tb-500 reconstitution
How many units is 2 mg of tb-500?
At 5 mg in 2 ml — 2,500 mcg/ml — it is 80 units on a U-100 syringe. At any other reconstitution it is a different number, which is why the table above states the vial and the diluent volume it was computed for.
What size vial should I reconstitute?
Whichever one you have — the calculator takes the strength as an input. What the vial size decides is how many doses it holds, and therefore whether it will still be good when you reach the last one: a 5 mg vial holds about 2 of the largest step above, and about 2 of the smallest. A vial holding more doses than its post-mixing window allows is a vial you will be throwing part of away, which is an argument for mixing a smaller working volume rather than a bigger one.
Does tb-500 accumulate between doses?
Its modelled half-life is 2 days, and that figure is an estimate from limited human data rather than a published value. A rough guide is that levels keep building for about five half-lives before they plateau, so the effect of a dose you take today is partly the effect of the doses before it. The TB-500 half-life page shows the curve and the steady-state arithmetic.
How long does it keep once mixed?
The entry's handling rule is in the fact box above, along with the caveat that comes with it: your supplier's own insert or certificate of analysis overrides anything generic. As a rule the constraint is the diluent rather than the peptide — bacteriostatic water's preservative is what makes repeated entry reasonable, and it is the reason a mixed vial is a weeks-not-months proposition.
Sold as part of a blend?
TB-500 is most often bought pre-mixed with BPC-157 rather than on its own — commonly five milligrams of each in one vial, and widely called the Wolverine blend. That changes the arithmetic on this page: both compounds share the water, so a draw large enough for a TB-500 dose carries roughly ten times a typical BPC-157 amount along with it. The BPC-157 and TB-500 blend calculator shows that split for your own vial. TB-500 is also in the GLOW and KLOW blends.
Related: TB-500 half-life and steady state, the generic reconstitution calculator, and the insulin syringe unit converter.
The app stores this vial's strength, its concentration and the date you mixed it, and counts the doses down as you log them.
Save this dose to your logThis calculator does the arithmetic you typed and nothing else. It does not know what is actually in your vial, whether the label is accurate, or anything about you. Confirm the vial strength and the diluent volume on your own label before you draw, and take dosing decisions to a qualified provider.