Compound reference
TB-500 Dosage Guide 2026: The Research vs Reported Use
Short answer
What it is: TB-500 is a synthetic seven-amino-acid fragment of thymosin beta-4, a 43-amino-acid repair peptide. The vial sold as TB-500 is the fragment, not the parent molecule.
The trial doses: the human trials dosed the parent molecule, thymosin beta-4 itself: 42 to 1,260 mg intravenous in healthy volunteers (Ruff, 2010), and 0.1% eye drops in dry eye trials.
The headline number: in a severe dry eye trial, 0.1% drops cut ocular discomfort 35.1% versus vehicle at day 56 (Sosne, Cornea 2015).
The catch: no published trial has dosed the TB-500 fragment in humans. Every number above belongs to the parent molecule.
Why it trips people: the protocols posted online run 2 to 6 mg a week, in milligrams, against syringes that read in units.
The status: not FDA approved as of July 2026, with an FDA advisory vote on compounding set for July 23, 2026. Every research figure comes straight from the cited papers, DOIs at the bottom.
The calculator
How it works: type a vial size, a water amount, a syringe type, and a dose in milligrams. It returns the concentration, the volume, and the reading on the syringe.
Units converter
Converts the numbers you type. It does not recommend a dose.
Arithmetic only. Check the result against your own vial, your own reconstitution, and your own syringe before you trust any unit count.
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On this page
Community reports, not a protocol
What do people report running?
The disclosure: I have no TB-500 log, and nothing in this section is mine. It is what the guides and forums report, copied here so you can see it next to the research.
The posted pattern: a loading phase of 4 to 6 mg a week, split into two injections, for 4 to 6 weeks.
Then maintenance: 2 to 2.5 mg a week, sometimes stretched to one injection every two weeks.
The route: subcutaneous in most posts, intramuscular in some. The 5mg vial is the common one, with 2mg and 10mg vials sold alongside it.
The stack: the posts almost always pair TB-500 with BPC-157 for injury work.
Where the numbers come from: not from any published trial. No published protocol exists for the fragment, so these figures circulate forum to forum and guide to guide.
What stands out to me: the guides present these as research protocols. There is no research behind them, and they deserve to be labeled as what they are: reported use.
Peer-reviewed trial data
What does the research show?
The identity first: TB-500 is the acetylated seven-amino-acid fragment Ac-LKKTETQ, derived from the active site of thymosin beta-4 (Rahaman et al., J Chromatogr B, 2024).
The blunt gap: that same paper states the biological effects of TB-500 have not been documented. In its own assays, only the metabolite Ac-LKKTE showed significant wound healing activity, not the parent fragment.
The pattern: the human record belongs to the parent molecule, thymosin beta-4 itself, dosed in hospitals and clinics across five very different studies.
| Study | What was dosed | People | What happened |
|---|---|---|---|
| Ruff 2010 | thymosin beta-4, IV, 42 to 1,260 mg, then daily for 14 days | 40 healthy volunteers | no serious adverse events, no dose-limiting toxicity |
| Treadwell 2012 | thymosin beta-4, two phase 2 wound trials | stasis and pressure ulcer patients | healing about a month faster in those who healed |
| Sosne & Ousler 2015 | 0.1% eye drops, 28 days | 72 with dry eye | primary endpoints missed; discomfort down 27% at day 28; no adverse events observed |
| Sosne, Dunn & Kim 2015 | 0.1% eye drops, six times daily, 28 days | 9 with severe dry eye | discomfort down 35.1% and staining down 59.1% at day 56 |
| Zhang 2025 | recombinant thymosin beta-4 after STEMI | 96 patients | early-treated subgroup improved at 90 days; overall not significant |
The safety study: Ruff et al. (Annals of the New York Academy of Sciences, 2010) ran four cohorts of ten healthy volunteers at 42, 140, 420, or 1,260 mg intravenous, single dose and then daily for 14 days.
The result: adverse events were infrequent and mild or moderate, with no dose-limiting toxicities and no serious adverse events.
The wound trials: Treadwell et al. (same journal, 2012) reviewed the dermal healing work, including two phase 2 trials in stasis and pressure ulcers. In the patients who did heal, healing came almost a month faster.
The larger eye trial: Sosne and Ousler (Clinical Ophthalmology, 2015) randomized 72 subjects to 0.1% drops or placebo for 28 days. Both primary endpoints missed significance; secondary endpoints improved, with discomfort down 27% on day 28, and no adverse events were observed.
The smaller eye trial: Sosne, Dunn and Kim (Cornea, 2015) treated nine patients with severe dry eye, twelve eyes on the 0.1% drops and six on vehicle, dosed six times daily. At day 56, ocular discomfort was down 35.1% and corneal staining down 59.1% versus vehicle.
The cardiac trial: Zhang et al. (Cardiovascular Research, 2025) randomized 96 heart attack patients after stenting. The subgroup dosed within 8 hours, 43 patients, showed smaller infarcted areas at 90 days; across all 96, the difference was not significant.
The hard line: don't merge any of this into a TB-500 dose. Different molecule, different routes, different conditions, and the fragment has no human record of its own.
35.1%
ocular discomfort down at day 56 vs vehicle, severe dry eye trial, parent molecule
59.1%
corneal staining down at day 56, same trial
1,260mg
top intravenous dose tested in healthy volunteers, thymosin beta-4
0
published human trials of the TB-500 fragment itself
Sosne, Dunn & Kim, Cornea 2015; Ruff et al., Ann N Y Acad Sci 2010; fragment gap: Rahaman et al., J Chromatogr B 2024.
Is the research dose the same as the posted dose?
The usual dodge: most pages either skip the question or post a schedule with nothing behind it. For TB-500, that dodge is the whole story.
What the research dosed
The molecule: thymosin beta-4, the parent, in hospitals and clinics. Intravenous doses up to 1,260 mg in healthy volunteers, 0.1% eye drops in dry eye, recombinant protein after heart attacks.
The purpose: safety, wound, eye, and cardiac studies. None was a dose-ranging study of TB-500 for recovery.
What the posts show
The molecule: the fragment, at home, 2 to 6 mg a week, subcutaneous, on a loading-then-maintenance pattern the guides copy from each other.
The evidence: no trial, no published protocol, no dose-ranging study behind any of it. The two columns share a name and little else.
Telling you which of those numbers to use is not something we will do.
The real question: it is your body, your risk tolerance, and a conversation with a doctor who knows your history. What this page can give you is the published record and the math behind a dose; the rest is yours to take up with someone qualified.
How does the units math work?
The point: run the arithmetic once, in general terms, attached to no one's dose.
Example one: say a 10mg vial gets reconstituted with 2mL of bacteriostatic water. That's 5mg per mL, or 5,000mcg per mL.
The syringe side: the standard U-100 insulin syringe holds 100 units per mL, so a unit is 1/100th of a mL, which at this concentration is 50mcg, or 0.05mg. From there: 2mg is 40 units, and 5mg is 100 units, a full 1mL syringe.
Change one thing: reconstitute the same 10mg vial with 1mL instead of 2mL. Concentration doubles to 10mg per mL.
What changes: each unit now equals 0.1mg instead of 0.05mg. The same 2mg is now 20 units, not 40.
The smaller vial: start from a 5mg vial with 2mL of water. That's 2.5mg per mL, each unit is 25mcg, and the same 2mg reads as 80 units.
The forum trap: that "40 units" someone read on a forum could be 2mg at one concentration and 4mg at another.
| Vial plus water | Concentration | 1 unit equals | What the article works out |
|---|---|---|---|
| 10mg + 2mL | 5mg per mL (5,000mcg per mL) | 0.05mg (50mcg) | 2mg is 40 units, 5mg is 100 units |
| 10mg + 1mL | 10mg per mL | 0.1mg | 2mg is 20 units, not 40 |
| 5mg + 2mL | 2.5mg per mL | 0.025mg (25mcg) | 2mg is 80 units |
| Syringe | Units per mL | 1 unit equals |
|---|---|---|
| U-100 | 100 units per mL | 0.01mL |
| U-40 | 40 units per mL | 0.025mL |
Trap number two: the syringe itself. Insulin syringes read in units at two common scales, whatever the concentration.
The two scales: U-100 holds 100 units to the mL, one unit is 0.01mL. U-40 holds 40 units to the mL, one unit is 0.025mL.
The 2.5x problem: draw on a U-40 assuming U-100 marks and each unit is 2.5 times the volume you think. Same vial, same concentration, same "40 units" on the barrel.
Before any of the arithmetic, confirm which syringe scale you are holding.
Both halves: that is the complete units-versus-mg tangle, both sides of it. The syringe never misreads. It simply does not know your concentration or its own scale; you do.
How many units is 2mg of TB-500?
The short answer: it depends on the concentration. At 5mg per mL (a 10mg vial plus 2mL of water), 2mg reads as 40 units on a U-100 syringe; at 10mg per mL (the same vial plus 1mL), 20 units; at 2.5mg per mL (a 5mg vial plus 2mL), 80 units.
The rule: there is no universal units number for any milligram amount. Get the concentration, check the syringe type, then do the arithmetic, or run the calculator above.
What's not known yet?
The status: TB-500 is not FDA approved as of July 2026. No thymosin beta-4 product is approved either.
The live event: an FDA advisory committee takes up TB-500-related bulk substances on July 23, 2026. It's a compounding-access question, not an approval, and the committee only advises; the FDA decides.
The April twist: TB-500 came off the FDA's Category 2 safety-concern list in April 2026 because the nominations behind it were withdrawn. Procedural, not an endorsement; it landed at the July review instead.
For athletes: WADA prohibits TB-500 and thymosin beta-4 at all times.
The parent's drug program: the developer of the thymosin beta-4 eye drop reports three phase 3 dry eye trials in over 1,600 patients that missed their co-primary endpoints, plus an FDA orphan drug designation in neurotrophic keratitis. Company-reported, and a designation is a development incentive, not an approval.
The real gaps:
- No published trial has dosed the TB-500 fragment in humans, so there is no verified dose, schedule, or duration for it.
- No verified safety data for injected TB-500; every adverse-event number on this page belongs to the parent molecule.
- No controlled study of the community loading and maintenance patterns that dominate online discussion.
Anyone who says otherwise is guessing.
The biggest gap: in our read, one gap sits above every dose number. A research-grade vial shows up with no independent verification of its contents.
All taken on trust: identity, purity, sterility, and the concentration printed on the label.
The quiet one: a mislabeled concentration breaks every units calc before it starts. The math is only as good as the printed mg number.
The real worry: that is not a dose question, a supply-chain question, and that is where our worry starts, not the units.
How this page is sourced
No secondary summaries: every trial figure above comes straight from the cited papers, reviews named as reviews; the pipeline status comes from the sponsor's public pipeline materials, named in the source pack. Not lifted from a secondary summary.
The six sources: below, with their DOIs and PubMed IDs. Pull them yourself, and compare our numbers with theirs.
The regulatory lines: the FDA, compounding, and WADA status lines were checked live on 19 July 2026 and carry a 90-day re-verify date. They move fast.
The standard: the full sourcing and citation-verification standard for this site lives on the methodology page. Any correction to any number here lands there first.
Last reviewed: 19 July 2026.
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1
Ruff D, Crockford D, Girardi G, Zhang Y. A randomized, placebo-controlled, single and multiple dose study of intravenous thymosin beta4 in healthy volunteers. Ann N Y Acad Sci. 2010;1194:223-9. doi:10.1111/j.1749-6632.2010.05474.x. PMID 20536472.
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2
Treadwell T, Kleinman HK, Crockford D, Hardy MA, Guarnera GT, Goldstein AL. The regenerative peptide thymosin β4 accelerates the rate of dermal healing in preclinical animal models and in patients. Ann N Y Acad Sci. 2012;1270:37-44. doi:10.1111/j.1749-6632.2012.06717.x. PMID 23050815.
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3
Sosne G, Ousler GW. Thymosin beta 4 ophthalmic solution for dry eye: a randomized, placebo-controlled, Phase II clinical trial conducted using the controlled adverse environment (CAE) model. Clin Ophthalmol. 2015;9:877-84. doi:10.2147/OPTH.S80954. PMID 26056426.
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4
Sosne G, Dunn SP, Kim C. Thymosin β4 significantly improves signs and symptoms of severe dry eye in a phase 2 randomized trial. Cornea. 2015;34(5):491-6. doi:10.1097/ICO.0000000000000379. PMID 25826322.
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5
Zhang Y, Dong Q, Bian X, et al. Recombinant human thymosin beta 4 improves ischemic cardiac dysfunction in mice and patients with acute ST-segment elevation myocardial infarction after reperfusion. Cardiovasc Res. 2025;121(17):2747-2758. doi:10.1093/cvr/cvaf223. PMID 41229390.
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6
Rahaman KA, Muresan AR, Min H, et al. Simultaneous quantification of TB-500 and its metabolites in in-vitro experiments and rats by UHPLC-Q-Exactive orbitrap MS/MS and their screening by wound healing activities in-vitro. J Chromatogr B Analyt Technol Biomed Life Sci. 2024;1235:124033. doi:10.1016/j.jchromb.2024.124033. PMID 38382158.
The disclaimer
Every page is reviewed by medical professionals before it ships, and written with longtime biohackers who were doing this before it was a trend. Reviewed still does not mean prescribed: nothing here is medical advice.
It is research, trial data, and reported use, with the numbers intact so you can check them. For decisions about your body, see a doctor who can look at your labs.
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