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TB-500 Dosage: Reported Figures, Units and Water per Vial

TB-500 has no label and no human trial of its own. The thymosin beta-4 trial doses, the 2026 registration and the vendor figures, dated, with units per vial.

Medibact Guides · Published 2026-09-18

Illustration: A partially filled glass vial next to a small beaker of water on a white bench.
Illustration

TB-500 has a dosage record that belongs mostly to a different molecule. The trials that people cite for it used full-length thymosin beta-4, a 43-residue protein given intravenously in gram-scale amounts; the product sold as TB-500 is described by its vendors as a seven-residue fragment given subcutaneously in milligrams. Between the two sits one 2026 registration with no dose in it and a set of vendor figures that agree with each other. This page reports each of those with its source and date, keeps the two molecules apart, and then converts the circulating figures into syringe units at the two vial sizes sold.

Thymosin beta-4 is a small actin-sequestering protein found in most human cells; TB-500 is the research-market name for a synthetic peptide based on its actin-binding segment. Medibact's TB-500 guide covers the molecule and its evidence; this page stays with figures. The dosage hub lists every compound's page.

What the sources state

Source Kind Figure Date read
DailyMed SPL searches, "TB-500" and "thymosin" Label search Zero records each; no approved product 2026-09-18
Ruff et al., Ann N Y Acad Sci 2010 (PMID 20536472) Trial publication Full-length thymosin beta-4, intravenous: 42, 140, 420 or 1,260 mg single dose, then the same dose daily for 14 days; 40 healthy volunteers; "well tolerated with no evidence of dose limiting toxicity" 2026-09-18
ClinicalTrials.gov search, thymosin beta-4 / TB-500 Registry 18 records: eye drops, topical gels, intravenous recombinant thymosin beta-4 at 0.25 to 25 mcg/kg, two withdrawn intravenous registrations, one naming TB-500 2026-09-18
NCT07487363 (Hudson Biotech; first posted 2026-03-23; 80 participants) Registry Low, medium and high dose arms of "TB-500 (thymosin beta 4 17-23 fragment)"; no milligram figure 2026-09-18
PubMed, "TB-500" or "TB500" Literature 32 records; seven about the peptide, all analytical, synthesis or animal work; no human dosing study 2026-09-18
FDA interim 503A list (2023-09-29); PharmExec 2026-07-24 Regulator record "Thymosin Beta-4, Fragment (LKKTETQ)" in Category 2 since 2023-09-29; removal signalled April 2026; advisory vote 8 to 6 with one abstention on 2026-07-23 2026-09-18
Vendor, clinic and forum pages Commonly cited 2 to 2.5 mg twice a week for four to six weeks, then 2 to 2.5 mg weekly or fortnightly 2026-09-18

Only the last row contains a subcutaneous milligram figure for the fragment, and it is the only row without a source that can be opened. The trial row is real, published and irrelevant to a 5 mg vial, for the reason set out next.

Two molecules under one name

The 2010 phase 1 study is the record most often cited as human evidence for TB-500, and it deserves to be read for what it is. RegeneRx gave synthetic full-length thymosin beta-4, all 43 residues, by intravenous infusion, in single doses of 42 mg to 1,260 mg and then daily for two weeks, to 40 healthy volunteers, and reported no dose-limiting toxicity. The lowest dose in that study is roughly seventeen times the entire contents of a 2.5 mg amount from a research vial, and it was given into a vein. The Chinese recombinant programme registered on ClinicalTrials.gov uses the same full protein at microgram-per-kilogram doses, also intravenously, after heart attack. Neither programme gave a seven-residue fragment under the skin, and no published study has. The doping-control literature, which is where the fragment appears in print, analyses the acetylated 17-23 sequence in urine and plasma; it measures the compound, it does not dose it.

Units per amount at each research-vial size

Research-market TB-500 is supplied in 5 mg and 10 mg vials. The table takes each at 1, 2 and 3 mL of water, states the concentration, and converts the circulating figures of 2, 2.5 and 5 mg into U-100 syringe units (100 units = 1 mL). A cell over 100 units does not fit one syringe.

Vial Water added Concentration 2 mg 2.5 mg 5 mg
5 mg 1 mL 5 mg/mL 40 50 100
5 mg 2 mL 2.5 mg/mL 80 100 200 (>1 syringe)
5 mg 3 mL 1.67 mg/mL 120 (>1 syringe) 150 (>1 syringe) 300 (>1 syringe)
10 mg 1 mL 10 mg/mL 20 25 50
10 mg 2 mL 5 mg/mL 40 50 100
10 mg 3 mL 3.33 mg/mL 60 75 150 (>1 syringe)

The table is the mirror image of the microgram peptides. Because the circulating figures are whole milligrams, extra water pushes an amount past one syringe quickly: a 5 mg vial at 3 mL cannot deliver even 2 mg in one draw, and 5 mg fits one syringe only at 5 mg/mL or above. A 5 mg vial holds two 2.5 mg amounts; a 10 mg vial holds four. The TB-500 calculator works any combination entered, and the Wolverine stack article covers the pairing with BPC-157 that most vendor schedules assume, with the blend calculator for two-vial arithmetic.

The 2026 registration, read closely

NCT07487363 is the only record on ClinicalTrials.gov that names TB-500. It proposes 80 adults with stable atherosclerotic cardiovascular disease, low, medium and high dose arms of the 17-23 fragment against a matching vehicle, and safety outcomes; the dose fields carry no milligram figure. Its sponsor, Hudson Biotech, holds eight registrations, all first posted between 2026-02-27 and 2026-04-01 and all at one hospital in Shenzhen, covering BPC-157, MOTS-c, tesamorelin, melanotan II, GHK-Cu, tirzepatide and retatrutide as well as TB-500; one reproduces the title and 2,539 enrollment of Lilly's completed SURMOUNT-1 trial, and one is titled "Mock Study". The registry accepts what sponsors submit and says so. These are the records' own contents, reported as they stand.

What the figures omit

The intravenous trial figures come with a different molecule, a different route, a healthy-volunteer population and a two-week duration. The registration comes with no dose. The vendor figures come with a loading phase, a maintenance phase and a cycle length that appear in no trial, and some of the pages that cite them say as much. The FDA's July 2026 vote concerned whether pharmacies may compound the fragment; it did not establish a dose and it did not approve anything. A research vial carries only its milligram content, and the arithmetic above transfers milligrams into units and nothing else.

BPC-157 dosage reports the compound TB-500 is most often paired with, and the pairing itself is covered in the Wolverine stack article. MOTS-c dosage reports another compound whose only 2026 registration comes from the sponsor described above. The general mixing procedure is documented on medibact.com's how to reconstitute peptides page; the reconstitution chart lists concentrations for every vial size the calculators cover.

The insulin syringe units how-to explains the U-100 and U-40 scales and how a milligram figure becomes a syringe reading.

What this page does not do

This page reports what DailyMed, ClinicalTrials.gov, PubMed, one press report of an FDA meeting and the public web state about TB-500 and thymosin beta-4 dosing, each with its source and date, and converts the circulating milligram figures into syringe units for two vial sizes. It does not recommend an amount, a frequency, a loading phase or a cycle, and it does not present the intravenous protein doses, the registration or the vendor figures as a dose for the fragment. Where the record is empty, the page says so and stops.

Sources and dates

Opened 2026-09-18: the DailyMed SPL searches for TB-500 and for thymosin (zero records each); PMID 20536472 (Ruff et al., Ann N Y Acad Sci 2010); the ClinicalTrials.gov search for thymosin beta-4, thymosin beta 4, TB-500 and RGN-352 (18 records) and the records NCT07487363, NCT04555824 and NCT07586865, plus a sponsor search for Hudson Biotech (eight records); the PubMed search for "TB-500" or "TB500" in titles and abstracts (32 records, summaries read; PMID 22962027, PMID 42542926); the September 2023 Category 2 list as reported by the Alliance for Pharmacy Compounding on 2023-10-30 and PharmExec's report of 2026-07-24 on the FDA advisory committee vote; and a read of vendor, clinic and forum pages for the figures in circulation. Corrections go to the contact page.

Frequently asked questions

What is the TB-500 dosage?

No label, trial or paper states one for the fragment sold as TB-500. The figures that circulate, 2 to 2.5 mg twice a week for four to six weeks and then 2 to 2.5 mg weekly or fortnightly, come from vendor, clinic and forum pages read on 2026-09-18 and cite no source. The one human injectable study in the record used the full 43-residue thymosin beta-4 protein intravenously at 42 to 1,260 mg, figures that describe a different molecule by a different route and do not transfer.

How many units is 2.5 mg of TB-500?

At 5 mg/mL, which a 5 mg vial reaches with 1 mL of water and a 10 mg vial with 2 mL, 2.5 mg is 0.5 mL, which is 50 units on a U-100 syringe. At 10 mg/mL it is 25 units, at 2.5 mg/mL it is 100 units, a full syringe, and at 1.67 mg/mL it is 150 units, more than one syringe. Because the circulating figures are whole milligrams, the more water is added the sooner an amount outgrows the syringe; the table on this page shows every combination.

Is there a TB-500 dosage chart?

Not from any source that can be opened. The loading-and-maintenance charts on vendor pages, read on 2026-09-18, agree with one another and cite nothing; the pages themselves sometimes note that the schedule is community-derived. The only chart on this page is arithmetic, converting 2, 2.5 and 5 mg into syringe units at each vial size and water volume. It converts the circulating figures; it does not endorse them, and no human trial of the fragment has been published.

What did the thymosin beta-4 trials use?

Full-length thymosin beta-4, not the fragment. The 2010 phase 1 (PMID 20536472) gave 42, 140, 420 or 1,260 mg intravenously, once and then daily for 14 days, to 40 healthy volunteers. The Chinese recombinant programme (NCT04555824 and successors) uses 0.25 to 25 micrograms per kilogram intravenously, and a 2026 registration proposes 10 or 20 micrograms per kilogram daily for seven doses after heart attack. The eye-drop and gel programmes are topical. None involved subcutaneous injection of a fragment.

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

Vendors describe TB-500 as a synthetic copy of residues 17 to 23 of thymosin beta-4, the seven-residue actin-binding segment, though some sell the full protein under the same name; the doping-control literature analyses the acetylated 17-23 fragment (PMID 22962027). Thymosin beta-4 itself is a 43-residue protein. A milligram of one is not a milligram of the other, which is why the intravenous trial doses on this page are reported as history and not converted into units.

What did the FDA decide in July 2026?

Its Pharmacy Compounding Advisory Committee voted 8 to 6, with one abstention, on 2026-07-23 in favour of TB-500 for the list of substances compounding pharmacies may use, after the agency had placed the fragment in Category 2 on 2023-09-29 and signalled a removal in April 2026. The vote is advisory; rulemaking follows, and the reports of the meeting quoted agency staff on the general lack of quality human data. Nothing in the vote establishes a dose.