Reconstitution calculator

TB-500 (Thymosin Beta-4) reconstitution calculator

A 5 mg TB-500 (Thymosin Beta-4) vial with 2.5 ml of bacteriostatic water holds 2,000 mcg per ml - so 2,000 mcg, as pure arithmetic, is a 100-unit draw on a U-100 insulin syringe. Change any of those numbers and the answer moves; the calculator below does the moving for you, and further down is the thing the vendor calculators never mention: where TB-500 (Thymosin Beta-4) actually stands with regulators right now.

TB-500 (Thymosin Beta-4) reconstitution calculator

Math on the numbers you enter - nothing more. Peptlas sells nothing and suggests no amounts.

Enter your intended dose above and the draw appears here, with the math shown.

Results are arithmetic, not advice. Peptlas is a regulatory-status reference: it does not recommend amounts, schedules, or use of any compound. Read the full disclaimer.

What you are working with

TB-500 (thymosin beta-4 fragment) ships as lyophilized powder, typically in 5 mg or 10 mg vials. Because amounts discussed around it are often whole milligrams, the milligram-to-microgram conversion (1 mg = 1,000 mcg) is where most math slips happen.

The reference table below shows the concentration each common vial-and-water combination produces. These are arithmetic facts about TB-500 (Thymosin Beta-4) vial sizes, not guidance about amounts - the same table exists for BPC-157 and Semaglutide, with different numbers.

Concentration by vial size and water volume for TB-500 (Thymosin Beta-4)
Vial+ 1 ml water+ 2 ml water+ 2.5 ml water
5 mg5,000 mcg/ml2,500 mcg/ml2,000 mcg/ml
10 mg10,000 mcg/ml5,000 mcg/ml4,000 mcg/ml

While you are here - where TB-500 (Thymosin Beta-4) stands

In limbo

TB-500 (a synthetic fragment associated with thymosin beta-4) is not an FDA-approved drug and is not on the Section 503A Bulk Drug Substances List, so pharmacies are not authorized to compound it. On July 23, 2026 the FDA's Pharmacy Compounding Advisory Committee voted 8-6, with 1 abstention, to recommend adding it - despite the FDA's own reviewers reporting that they could not identify a single human clinical study of the substance. The vote is advisory and does not bind the FDA.

In limbo: Nominated or removed from a restricted list but NOT approved - the headline implies a change, but the legal reality did not move. Verified Aug 11, 2026 (ET) · status held since Jul 23, 2026.

What changed last

  1. FDA advisory committee (PCAC) voted 8-6, with 1 abstention, to recommend adding TB-500 to the 503A list - despite FDA reviewers reporting they could not identify a single human clinical study. Advisory only: TB-500 is still not on the list and still not legal to compound.

    Not legalizedView on healio.com

  2. Removed from FDA Category 2 after nominations were withdrawn - but it was never in Category 1, so it is still not legal to compound.

    Not legalizedView on orrick.com

TB-500 (Thymosin Beta-4) math, asked and answered

How much bacteriostatic water do you add to a 5 mg TB-500 (Thymosin Beta-4) vial?
Any amount - water sets the concentration, not the contents. With 2.5 ml, a 5 mg vial gives 2,000 mcg/ml; with 1 ml it gives 5,000 mcg/ml. More water means the same dose is a larger, easier-to-read draw on the syringe. There is no single correct volume, which is why this page calculates instead of prescribing.
How many insulin-syringe units is 2,000 mcg of TB-500 (Thymosin Beta-4)?
It depends entirely on how the vial was reconstituted. As arithmetic: in a 5 mg vial with 2.5 ml of water (2,000 mcg/ml), 2,000 mcg is 100 units on a U-100 syringe. With 1 ml of water instead, the same 2,000 mcg is 40 units. The calculator above does this for your actual numbers.
Is TB-500 (Thymosin Beta-4) legal right now?
In limbo - TB-500 (a synthetic fragment associated with thymosin beta-4) is not an FDA-approved drug and is not on the Section 503A Bulk Drug Substances List, so pharmacies are not authorized to compound it. On July 23, 2026 the FDA's Pharmacy Compounding Advisory Committee voted 8-6, with 1 abstention, to recommend adding it - despite the FDA's own reviewers reporting that they could not identify a single human clinical study of the substance. The full, source-linked answer is on the TB-500 (Thymosin Beta-4) status page, verified Aug 11, 2026 (ET).
What form does TB-500 (Thymosin Beta-4) come in?
TB-500 (thymosin beta-4 fragment) ships as lyophilized powder, typically in 5 mg or 10 mg vials. Because amounts discussed around it are often whole milligrams, the milligram-to-microgram conversion (1 mg = 1,000 mcg) is where most math slips happen.