Read This First
This page is not built on clinical evidence. Cost and access are commercial and legal facts, not scientific findings. They come from the trial registry and the regulatory record, and they change on timescales of months.
Thymosin beta-4 has no list price, no prescription route, no insurance pathway and no seller, because it is an investigational drug that exists only inside its developers' trials.1 What has a price is TB-500, the seven-residue fragment sold under its name, and that is a different compound with its own cost page.
This page publishes no prices. What follows is what determines the money, which for this compound begins with the fact that the thing being priced is not the thing being named.
Why There Is No Price
What a Price Normally Represents
For an approved medicine, a price sits on top of a known quantity of a known substance, made to a validated standard, for a stated indication, with a documented effect. For an investigational drug, the same things exist but are not for sale: the developer makes it to a standard, gives it to trial participants, and measures the effect. There is no transaction and no price.
Thymosin beta-4 is in that second position. RegeneRx, ReGenTree and Beijing Northland make characterised versions and administer them in trials. None sells it.2
What Is Being Sold Under the Name?
TB-500, almost without exception. The 43-residue protein is long for routine synthesis, and no peptide vendor has an incentive to make it when the fragment costs a fraction to produce and carries the same name in the buyer's mind. A price quoted for "thymosin beta-4" by a research vendor or a clinic is, in nearly every case, a price for Ac-LKKTETQ. The sourcing page covers how to tell.
That means the cost question for thymosin beta-4 collapses into the cost question for TB-500, with one addition: the buyer is paying the fragment's price for the protein's research record, and the record does not transfer.
Access
Is There a Legal Route?
One, and it is not a purchase. Thymosin beta-4 is available to participants in its clinical trials. As of this page's verification date, the recruiting trials are SEER-2, for neurotrophic keratopathy, at ophthalmology sites in the United States, and a Chinese Phase 2 in acute myocardial infarction listed to begin in 2026.12 Both have narrow eligibility criteria that describe a specific disease, and neither has anything to do with tendon, muscle or recovery.
Trial participation is not a way of getting the drug cheaply. Participants may receive placebo, are subject to criteria they do not control, and take on trial obligations. It is a legitimate route, with the trade-offs of a trial rather than the terms of a purchase. The registry is the place to check, since recruiting status changes.3
Can It Be Prescribed or Compounded?
No. It is not approved, not a component of an approved drug, and not on the 503A bulks list; it has never been nominated for one. The FDA's compounding record concerns the fragment, TB-500, which was placed in Category 2 in 2023 and considered by the advisory committee in July 2026 for wound healing.45 Even a favourable outcome there would concern the fragment, and the FDA has not acted on it.
Does Insurance Cover It?
No, and there is nothing to appeal. Payers reimburse approved products for approved indications. With no approval anywhere there is no covered indication and no billing code attached to one.
Can HSA or FSA Funds Be Used?
Tax-advantaged health accounts cover qualified medical expenses, which generally requires a legitimate medical purpose and often a provider's documentation. A product that cannot be lawfully dispensed for human use sits poorly against that. The account holder carries the consequences of a disallowed expense; the question belongs with the plan administrator.
What the Money Buys
Where Does the Spread Between Sellers Come From?
| Cost component | Present in | What it buys |
|---|---|---|
| Consultation and clinician time | Clinics, telehealth | A history, an examination, a record, and someone accountable |
| Premises, staff and liability | Clinics | Overhead and recourse, not product |
| The name | All channels | The 43-residue protein's trial record, attached to a vial of the fragment; this is the component unique to this compound |
| Bundling with BPC-157 | Clinics, vendors | A second compound and a schedule, priced together; the one controlled animal comparison found no additive benefit6 |
| Marketing and affiliate commission | All channels, often invisible | Nothing for the buyer |
| The compound itself | All channels | Raw material of unverified identity, at a cost small relative to the components above it. ONPEPS publishes no prices; read this as reasoning about cost structure rather than a measured breakdown |
None of the spread buys verified product quality, because no channel offers that. A higher price buys service and accountability where those exist. It does not buy the protein, and it does not buy the evidence.
Does "Full Length" Cost More?
Some vendors list "full-length thymosin beta-4" at a premium over TB-500. Whether the premium buys the protein is a question a certificate with an observed mass could answer, and most do not. A 43-residue synthetic of verified sequence would be an expensive product to make; a buyer paying a modest premium should ask what makes it modest.
The Spending Decision
What Result Is Being Paid For?
The product copy promises tendon repair, injury recovery and healing, citing the protein's research. That research, in humans, consists of intravenous safety in volunteers, topical gels on chronic ulcers with modest signals, eye drops that failed twice at Phase 3 and once narrowly succeeded in a rare corneal disease, and unpublished Chinese cardiac trials.789 None of it concerns tendon, muscle or injury, none of it used subcutaneous injection, and none of it used the fragment.
So the purchase is a vial of one molecule, bought on the record of another, for a use neither has been tested for in a human being.
The protein's evidence is real and the developers are still spending money to extend it. That is a reason to watch the trials. It is not a reason to pay for a fragment.
What Is the Risk Side of the Ledger?
Two things belong alongside the price. The protein has never been given subcutaneously in a trial, so there is no human safety data for the route everyone uses.7 And it is prohibited in sport under WADA section S2 by name, with a validated test and a precedent of 34 players banned on circumstantial evidence about what had been injected.1011 For a tested athlete that cost dwarfs the vial.
What Should Be Asked Before Paying?
Which molecule is this: the 43-residue protein or the 7-residue fragment? What mass does the certificate show?
Which human trial of this molecule, by this route, measured the outcome you are promising?
On what legal basis are you supplying this?
What monitoring is included, and who do I contact if I have a reaction?
Does anyone here earn commission on product sales?
The first question is the informative one. A seller who cannot say which molecule they are selling has answered the second.
What Would Change This Page
Approval
If SEER-2 succeeds, thymosin beta-4 could become an approved eye drop for neurotrophic keratopathy, with a list price, a specialty pharmacy channel and coverage for a rare disease.1 That would change this page for people with neurotrophic keratopathy. It would change nothing for anyone buying a vial for their shoulder, because an ophthalmic solution is not an injectable and an approval for one indication is not evidence for another.
A Note on Price Comparisons
Figures circulate comparing "thymosin beta-4" favourably with growth hormone or with clinic-administered biologics. The comparison is between an unverified fragment and characterised drugs, and it says nothing about value. ONPEPS does not make it.
Related ONPEPS Coverage
Thymosin beta-4 library entry: the trials, the missed endpoints and the keratopathy signal
Thymosin beta-4 sourcing and quality: a 43-residue protein nobody sells
TB-500 cost and access: pricing drivers, clinic vs vendor, and insurance
TB-500 vs BPC-157: mechanisms, use cases and the Wolverine stack
Sources
ClinicalTrials.gov. NCT05555589. SEER-2. Sponsor ReGenTree, LLC. Phase 3, 70 participants estimated, recruiting. Record retrieved 16 September 2026. clinicaltrials.gov/study/NCT05555589
ClinicalTrials.gov. NCT07586865. Recombinant Human Thymosin Beta 4 for Injection (NL005) for Acute Myocardial Infarction. Sponsor Beijing Northland Biotech. Phase 2, not yet recruiting. Record retrieved 16 September 2026. clinicaltrials.gov/study/NCT07586865
ClinicalTrials.gov. Studies listing thymosin beta 4 as an intervention. Registry search; recruiting status changes continuously. clinicaltrials.gov
US Food and Drug Administration. Category 2 of the Bulk Substances Nominated Under Sections 503A or 503B of the Federal Food, Drug, and Cosmetic Act. Entry for thymosin beta-4 fragment (LKKTETQ). Content current as of 22 April 2026. fda.gov
US Food and Drug Administration. July 23-24, 2026: Meeting of the Pharmacy Compounding Advisory Committee. Docket FDA-2025-N-6895. fda.gov
Biçer O, Adanir O, Güleryüz Y, Balci EC, Dinçel YM, Yenigün MY, et al. Effects of BPC-157 and TB-500 on Achilles tendon healing in rats: a histopathological and biomechanical study. Jt Dis Relat Surg. 2026;37(3):822-837. Open access. pubmed.ncbi.nlm.nih.gov/42542926
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;1194:223-229. Paywalled. pubmed.ncbi.nlm.nih.gov/20536472
ClinicalTrials.gov. NCT03937882. ARISE-3. Sponsor ReGenTree, LLC. Phase 3, 700 participants, completed, results posted. Record retrieved 16 September 2026. clinicaltrials.gov/study/NCT03937882
Sosne G, Kleinman HK, Springs C, Gross RH, Sung J, Kang S. 0.1% RGN-259 (thymosin ß4) ophthalmic solution promotes healing and improves comfort in neurotrophic keratopathy patients in a randomized, placebo-controlled, double-masked phase III clinical trial. Int J Mol Sci. 2022;24(1):554. Open access. pubmed.ncbi.nlm.nih.gov/36613994
United States Anti-Doping Agency. 2018 Prohibited List: Summary of Major Changes. Archived advisory. usada.org
ABC News (Australia). Essendon supplements saga: players banned for 12 months after WADA appeal upheld by Court of Arbitration for Sport. 12 January 2016. abc.net.au
Not Medical or Financial Advice
Thymosin beta-4 is not approved for human use in any jurisdiction and is available only inside clinical trials. Treatment decisions belong with a qualified healthcare provider. Nothing on this page is a recommendation to buy or not to buy anything; it is an account of what is known about what the money would be spent on.
Sources verified 16 September 2026. Trial status changes and an approval would change parts of this page. Re-verify before relying on anything here.