Eye surface healing
In a phase III trial of full-protein eye drops, 6 of 10 patients healed a stubborn corneal wound in four weeks, versus 1 of 8 on placebo. That was a trend, not a significant gap (p = 0.0656).11
Peptide Guide · Recovery and repair
TB-500
Thymosin beta-4 fragment (Ac-LKKTETQ)
TB-500 is the recovery peptide that usually comes up in the same breath as BPC-157. It is a seven-piece fragment of a 43-piece repair protein, and what it leaves out matters as much as what it keeps.
Free to join · One email when peptide care opens · Most lab results in 3–5 business days
- Studied for
- Wound, soft-tissue and heart repair
- Evidence
- Early research
- Taken as
- Injection under the skin, as prescribed
TB-500, in short
TB-500 is a synthetic seven-amino-acid peptide, Ac-LKKTETQ, copied from the actin-binding site of thymosin beta-4, a repair protein found in almost every cell. That site helps repair cells move into injured tissue and helps new blood vessels form. It is studied for soft-tissue, wound and heart repair, mostly through research on the full parent protein.
Medically reviewed by Robert Lufkin, MD (opens in a new tab)
Chief Medical Officer, Vitals Vault · Updated · 19 sources
Before you consider TB-500
How does TB-500 work?
TB-500 copies the part of a repair protein that helps cells move.
Moves repair cells
In lab tests, this short piece helped the cells that line blood vessels crawl toward damage.64
Grows new blood vessels
In lab tests, the short piece grew new vessels about as well as the whole protein.6
A survival signal it may lack
The whole protein helped heart cells survive injury in mice. Nobody has shown the fragment does this.10
TB-500 benefits: what it is studied for
Only the vessel result below tested the TB-500 piece. The rest tested the full protein, and TB-500 has no human trials of its own.
- Human study01
- Human study02
Skin wounds and ulcers
In two phase 2 trials of the full protein in stasis and pressure ulcers, patients who healed did so almost a month faster.12
- Animal study03
Heart repair
After a heart attack in mice, the full protein improved heart muscle survival and heart function, published in Nature in 2004.10
- Lab study04
New blood vessel growth
In human cells and chick vessel tissue, the seven-amino-acid piece matched the full protein’s ability to sprout new vessels.6
What the research shows
Early research- 1 · Cells in a lab Studied
The seven-amino-acid piece matched the full protein at growing new vessels in human cells and chick tissue.6
Shows a mechanism
- 2 · Animals Studied
The full protein improved heart muscle survival and function after a heart attack in mice.10
Shows an effect in a body
- 3 · PeopleNot yet
No human trials of TB-500 itself. Trials of the full protein in eye and skin wounds showed faster healing or a trend toward it.111217
Shows it works in people
The full guide to TB-500
Why anti-doping labs know TB-500 better than most doctors
Some of the most careful chemistry ever done on TB-500 happened at a racetrack. In 2012, scientists at the Hong Kong Jockey Club’s racing laboratory described a veterinary product called TB-500 and set out to catch horses that had been given it. The same year, a doping control lab in Ghent took apart TB-500 products to see what was actually inside the vial.
Both labs found the same thing. The key ingredient was a seven-amino-acid peptide, LKKTETQ, with an acetyl group added to one end. That short sequence is lifted straight from thymosin beta-4, a much larger protein your own cells make. Racing and anti-doping chemists, more than clinicians, did the work of pinning down what TB-500 actually is.
The parent protein has its own odd history. Thymosin beta-4 was first isolated from calf thymus and was thought to be a thymic hormone. In 1991, researchers studying platelets found that at least half the actin in a resting platelet sits unassembled, and that most of this reserve is held by a small peptide they had named Fx. When they sequenced Fx, it was identical to thymosin beta-4.
So a supposed thymus hormone turned out to be one of the most common molecules in the body, a protein that stockpiles the raw material cells use to move. TB-500 copies the short stretch of that protein involved in grabbing actin, though a copied grip is not proof the fragment stockpiles actin the way the whole protein does. To understand what it can and cannot do, you have to start with actin.435
What TB-500 is, and how it differs from thymosin beta-4
Thymosin beta-4 is a chain of 43 amino acids. TB-500 is 7 of them, positions 17 to 23, which read LKKTETQ in the one-letter code chemists use. The Hong Kong lab noted that the acetyl cap on the front of the TB-500 peptide is artificial, added by its makers rather than copied from nature.
Those seven amino acids are the actin-binding site of the full protein. The Hong Kong team described this segment as the region responsible for actin binding, cell migration and wound healing. The product itself was marketed with claims of new blood vessels, skin cell migration, collagen deposition and lower inflammation.
That is a lot to ask of a peptide one-sixth the size of its parent. The fair way to read TB-500 research is in two layers. One layer is direct evidence on the fragment, mostly from cell studies and anti-doping chemistry. The other is the much larger body of work on full-length thymosin beta-4, which TB-500 borrows from.
The parent protein is no rarity. Thymosin beta-4 is the most abundant member of its family in mammalian tissue and is regarded as the main molecule that holds loose actin inside cells. Your platelets carry large amounts of it and release it at the site of an injury, where it helps start the repair process. TB-500 copies a sliver of something your body already makes in bulk.432612
How TB-500 works: actin, movement and new vessels
Every cell that crawls, from a skin cell closing a cut to an endothelial cell building a new capillary, moves by assembling actin filaments at its leading edge and taking them apart at the back. That takes a ready supply of loose actin. Thymosin beta-4 binds single actin molecules one to one and holds them unassembled, a reserve the cell can draw on when it needs to move.
In 2003, a team at the National Institutes of Health asked which part of thymosin beta-4 drives its effect on blood vessels. Using natural protein, fragments and synthetic peptides, they found that the seven-amino-acid actin-binding motif was essential. In migration assays with human endothelial cells and in vessel-sprouting assays from chick aortas, the motif and the full protein showed near-identical activity.
Peptides missing any piece of that motif did nothing. The same seven amino acids also turned out to be the main site where cells attach to thymosin beta-4. This is the most direct lab evidence that the motif TB-500 copies is biologically active, and it points to a specific job, helping cells migrate and sprout new vessels. One caveat: the abstract does not say whether the tested peptide carried TB-500’s artificial acetyl cap.
The full protein does more. In a 2004 Nature study, thymosin beta-4 formed a complex with two partner proteins, PINCH and integrin-linked kinase, which switched on Akt, a survival signal that helped heart muscle cells live through injury. That study used the whole protein, so whether TB-500 carries this survival signal is an open question.5610
Seven of 43: what the fragment keeps and what it leaves behind
Thymosin beta-4 behaves more like a multitool than a single key. Different stretches of the protein seem to do different jobs, and TB-500 keeps only one of them.
The front end of the protein, four amino acids called SDKP, gets cut free in the body by two enzymes, meprin alpha and prolyl oligopeptidase, to make a small peptide called Ac-SDKP. A 2023 review by thymosin beta-4’s own pioneers concluded that this front end appears to hold most of the protein’s anti-fibrotic activity, preventing and in animal models even reversing scarring in the liver, lung, heart and kidney.
TB-500 does not contain that sequence. It carries the migration and blood vessel piece and leaves out the region thought to account for much of the anti-scarring activity. Whether that changes how an injury scars has never been tested, but for someone hoping for less scar tissue, it is a gap worth knowing about.
This is a hypothesis built from cell and animal work, and nobody has compared TB-500 with full-length thymosin beta-4 head to head in people. But it gives you a sharper question to bring to a clinician than whether TB-500 works. Ask which part of thymosin beta-4’s biology your problem actually needs.876
TB-500 benefits borrowed from the eye and skin trials
All of the human evidence connected to TB-500 comes from full-length thymosin beta-4, in eye and skin trials, intravenous phase I studies and a heart attack trial. The most rigorous was a phase III trial of thymosin beta-4 eye drops in neurotrophic keratopathy, a rare condition in which the cornea loses nerve supply and surface wounds refuse to close.
After four weeks, 6 of 10 patients on the drops had completely healed, compared with 1 of 8 on placebo. With only 18 people, that difference landed at p = 0.0656, a strong trend that fell just short of the usual bar for statistical significance. Comfort, foreign-body sensation and dryness improved significantly, and no significant side effects were seen.
Skin tells a similar story. In animal models, including diabetic and aged mice and steroid-treated rats, thymosin beta-4 sped the healing of full-thickness wounds. In two phase 2 trials of stasis and pressure ulcers, the patients who healed did so almost a month faster. These results support the idea that the protein speeds repair at a wound surface.
None of these trials used TB-500, and none tested an injected fragment. The eye trial put the full protein straight onto the cornea. That does not make the results irrelevant to TB-500, but it does mean the bridge from those trials to an injected fragment is an assumption.1112
TB-500 for injury recovery, muscle and the heart
The heart is where thymosin beta-4 became famous. In the 2004 Nature study, mice treated after a blocked coronary artery had more surviving heart muscle cells early on and better heart function afterward. The finding launched two decades of work on the protein as a cardiac repair signal.
The human follow-up has been slow and mixed. A 2025 randomized trial assigned 96 people to recombinant thymosin beta-4 or placebo after a major heart attack and an opened artery. Across everyone, the infarcted area was not significantly smaller. In the subgroup of 43 who got their first dose within eight hours of the artery being opened, it was.
Athletes care more about tendons, ligaments and muscle. Here the evidence is thinner still. A 2015 review by the protein’s leading researchers listed ligament, bone and spinal cord repair as promising future uses based on animal work, alongside brain repair after stroke or trauma. There are no published controlled human trials of TB-500 or thymosin beta-4 for a sports injury.
So TB-500’s reputation in recovery rests on a plausible mechanism and on the parent protein’s results in other tissues. No study cited here shows that injected TB-500 improves a human tendon, ligament or muscle injury.10132
What we know about TB-500 in people
The honest summary is short. TB-500 has no published human trials of its own. Everything known about safety and dosing in people comes from full-length thymosin beta-4, given intravenously in phase I studies or applied to the eye and skin.
Those phase I studies are reassuring for the parent protein. In 2010, a randomized phase I study enrolled 40 healthy volunteers in four rising-dose groups, some on placebo, given single and then repeated daily infusions. Adverse events were infrequent and mild or moderate, with no dose-limiting toxicity. A 2021 study of a recombinant version in 84 healthy volunteers found the same, with no build-up after repeated dosing.
For the fragment, what exists is detection chemistry. Labs have identified TB-500’s breakdown products and detected them in horse urine and plasma after a dose, which matters to anti-doping officials. How it behaves in a human body, and whether an injected fragment reaches an injured tendon in useful amounts, has not been published.
The study that would settle the main question is easy to describe. Take people with a common soft-tissue injury, give half of them injected TB-500 and half a placebo, keep the rehab identical, and measure pain, function and tissue healing. That trial has not been published, so anyone using TB-500 today is relying on the parent protein’s record and the fragment’s lab biology.1415417
TB-500 side effects and safety
Because TB-500 has not been studied on its own in people, its human side effect profile is unknown. The nearest record, short-term studies of full-length thymosin beta-4, shows a well-tolerated protein, but a different molecule’s record cannot vouch for the fragment. FDA’s April 2026 compounding page made the gap explicit, noting that it had not identified human exposure data for the TB-500 fragment.
One theoretical concern is cancer. The same talents that help a wound, cell migration and new blood vessels, also help tumors spread. In a 2003 mouse study, melanoma cells engineered to overproduce thymosin beta-4 grew larger tumors and formed more than four times as many lung nodules as control cells. That was the tumor’s own protein, not an injected peptide, but it is the reason a cancer history belongs in the conversation.
The practical risk is quality. Much of what we know about TB-500 products comes from anti-doping labs that had to analyze them because their contents were uncertain. A prescription filled by a licensed 503A compounding pharmacy is a different product from a vial sold online for research use.
People who should talk to a clinician first include anyone with a personal history of cancer, anyone pregnant or breastfeeding, anyone with liver or kidney disease, and any tested athlete.14151793
Which labs make sense around a TB-500 course
Since TB-500 has no human pharmacology data of its own, general baseline labs give a clinician context on your health before any course. ALT, alanine aminotransferase, is a liver enzyme that rises in the blood when liver cells are stressed. None of these markers is a test for TB-500 itself.
eGFR, the estimated glomerular filtration rate, reflects how well your kidneys filter blood. Small peptides are generally cleared through the kidneys, so knowing where you start is sensible. hs-CRP, high-sensitivity C-reactive protein, tracks low-grade inflammation across the body, which can slow healing anywhere.
This is the Vitals Vault approach to peptide care. A blood panel at Quest Diagnostics comes first, a licensed clinician reviews your results and history and decides whether TB-500 fits, and the course ends with a retest of the same markers.17
Where TB-500 stands in 2026
On October 29, 2026, NCPA reported that FDA granted enforcement discretion allowing 503A compounding pharmacies to prepare TB-500, along with five other peptides, for individual patients with a prescription. There is no end date, and final rulemaking is pending. TB-500 is still not an FDA-approved drug. Full-length thymosin beta-4 is not part of that policy.
In sport, TB-500 is plainly banned. WADA prohibits thymosin beta-4 and its derivatives, and the published detection methods mean it can be found in testing. Anyone in tested competition should treat it as off limits.1617194
What this means for you
TB-500 is a seven-amino-acid slice of a repair protein your body already makes in abundance. In the lab, that slice carries the protein’s ability to move repair cells and grow new vessels. The human trials that make thymosin beta-4 interesting used the full protein, on the eye, skin and heart, and TB-500 leaves out the part linked to anti-scarring.
If you are considering it, the better question is what your injury is missing. Lab work hints that TB-500’s mechanism touches cell traffic and blood supply, though no trial shows which human injuries, if any, benefit. If the problem is load, sleep or an unresolved inflammatory driver, the peptide is unlikely to be the lever that matters most. A clinician can check the established causes of slow healing first; no lab test predicts who would respond to TB-500.6711
What to expect with TB-500
A responsible start looks like a health history, a baseline blood panel and a clinician’s decision on whether TB-500 fits your injury. The prescriber sets the course length, and it ends with a retest of the same markers.
On timing, the only human signals come from the parent protein. In the eye trial, healing was judged at four weeks, and in the skin ulcer trials, people who healed did so almost a month sooner. Those are wound surfaces treated directly, so they hint at a time frame of weeks for repair signals to show, without promising the same for a tendon.1112
Key TB-500 studies
Safer et al., 19915
Laboratory biochemistry · Human platelets
Thymosin beta-4 is Fx, the peptide holding most of the unassembled actin in resting platelets
Limits: Basic science, no treatment tested
Philp et al., 20036
Cell and tissue assays · Human endothelial cells, chick aortic rings
The seven-amino-acid actin-binding motif matched the full protein’s vessel-growth activity
Limits: Lab assays only, not people
Ho et al., 2012; Esposito et al., 201243
Anti-doping chemistry · TB-500 products; horses
TB-500’s active ingredient is acetylated LKKTETQ, detectable in urine and plasma
Limits: Identifies the product, does not test benefit
Ruff et al., 201014
Phase I randomized trial · 40 healthy volunteers, including placebo
Intravenous full-length thymosin beta-4 well tolerated, no dose-limiting toxicity
Limits: Full protein, not TB-500; short term
Sosne et al., 202211
Phase III randomized, placebo-controlled trial · 18 adults with neurotrophic keratopathy
6 of 10 healed at four weeks versus 1 of 8; comfort improved
Limits: Healing gap not significant (p = 0.0656); eye drops of the full protein
TB-500 myths and evidence
TB-500 is just thymosin beta-4 under another name
TB-500 is a seven-amino-acid fragment of the 43-amino-acid protein. It keeps the actin-binding site but not the front end that holds most of the anti-scarring activity, and the human trials used the full protein.37
TB-500 has been proven in human trials
It has not. The phase I, eye, skin and heart trials all tested full-length thymosin beta-4. TB-500 has no published human trials of its own.141117
A seven-amino-acid fragment is too small to do anything
In NIH cell studies, the seven-amino-acid motif matched the full protein’s ability to drive endothelial migration and vessel sprouting, while fragments missing part of it were inactive.6
TB-500 is undetectable in drug tests
Anti-doping labs have published methods that detect TB-500 and its breakdown products in urine and plasma, and WADA prohibits it.4319
How is TB-500 taken?
Compounded TB-500 is prepared as an injection under the skin. Your prescriber sets the dose, frequency and length of a course. It is often discussed alongside BPC-157 for recovery.
TB-500 dosage
There is no FDA-approved TB-500 dose, and no human dose has been published. In its July 2026 review, FDA found no clinical studies of TB-500 in people, so online dosing charts are not based on human trials. The human trial doses of full-length thymosin beta-4 do not carry over to this fragment. Your clinician sets any dose.1
Typical TB-500 dosage
No human dose of TB-500 has been published. FDA reviewed TB-500 for compounding in July 2026 and found no clinical studies or other human data, so every dose that circulates online is untested in people. Trials of full-length thymosin beta-4 do not tell you a dose for this short fragment. A clinician would have to decide any use and dose.
Already have a prescribed dose? The peptide dosage calculator turns it into the units to draw on an insulin syringe.
No dose has been published from studies in people yet, so there is no typical dose to show. A prescribing clinician decides whether TB-500 fits and how it is given.
Is TB-500 right for you?
A clinician makes the call. These are the questions they will ask first.
It may suit
- Adults recovering from soft-tissue injury who want a supervised option alongside rehab
- People considering BPC-157 and TB-500 together, under one clinician
- Anyone who wants labs before and after
Talk to a clinician first if you are
- A personal history of cancer
- Tested athletes (WADA prohibits it)
- Pregnant or breastfeeding
- Living with kidney or liver disease
Vitals Vault peptide care starts with a blood panel and a licensed clinician, and ends with a retest.
Get early access to peptide careTB-500 vs BPC-157
| Attribute | TB-500 | BPC-157 |
|---|---|---|
| Comes from | Thymosin beta-4, a repair protein | A gastric juice protein |
| Main action studied | Cell movement, new blood vessels | New blood vessels, growth signals |
| Best known for | Wound, eye and heart repair | Tendon, ligament and gut repair |
| Usual form | Injection | Injection or oral |
Repair is a logistics problem
What else moves the same system
- 01Rehab and loadingKeep the physiotherapy going. A peptide does not replace it.
- 02Protein and sleepHealing tissue needs raw materials and good sleep. Both are easy to check.
- 03Track the baselineLiver, kidney and inflammation markers before a course, and again after.
Labs to check with TB-500
A blood test before you start and a retest after shows what actually changed for you. It is how Vitals Vault approaches every treatment.
- TestA baseline panel at Quest Diagnostics.
- DecideA licensed clinician reviews your history and results.
- RetestThe same markers again, side by side.
Is TB-500 FDA approved?
No. Since October 29, 2026, FDA allows 503A pharmacies to compound TB-500 for individual patients with a prescription, under enforcement discretion, while the final rule is pending.16
What FDA’s decision meansTB-500 timeline
1991
Thymosin beta-4 is shown to be the main actin-holding peptide in human platelets.5
2003
NIH researchers show the seven-amino-acid actin-binding site drives thymosin beta-4’s blood vessel growth.6
2004
Nature study shows thymosin beta-4 supports heart repair in mice.10
2010
Phase I study finds IV thymosin beta-4 well tolerated in healthy volunteers.14
2012
Anti-doping labs identify the Ac-LKKTETQ fragment in TB-500 products.34
2022
Phase III eye-drop trial of thymosin beta-4 published.11
April 2026
FDA’s compounding safety page lists TB-500 as a nominated bulk substance and notes how little human safety data exists.17
July 2026
FDA’s Pharmacy Compounding Advisory Committee votes to recommend adding TB-500 to the 503A bulks list.16
October 29, 2026
FDA grants enforcement discretion, so 503A pharmacies can compound TB-500 with a prescription. No end date; final rule pending.16
TB-500 questions
What is TB-500 used for?
TB-500 is used for recovery from soft-tissue injuries. Its parent protein, thymosin beta-4, is studied for wound, eye, heart, ligament and muscle repair. It is not FDA-approved to treat any condition.
What are the benefits of TB-500?
Research on thymosin beta-4 shows a strong trend toward faster corneal healing in a phase III trial, faster healing of skin ulcers in patients who healed, and better heart repair in mice. TB-500 carries the protein’s actin-binding region, which drives cell movement and new blood vessels in lab studies.
How does TB-500 work?
TB-500 copies the part of thymosin beta-4 that binds actin, the scaffold cells use to crawl. In cell and vessel-sprouting studies, this short motif helped endothelial cells migrate and form new vessels about as well as the full protein.
Is TB-500 the same as thymosin beta-4?
No. Thymosin beta-4 is the full 43-amino-acid protein. TB-500 is a seven-amino-acid synthetic fragment of it, identified in products as Ac-LKKTETQ. The human trials were done with the full protein.
What are the side effects of TB-500?
Full-length thymosin beta-4 was well tolerated in phase I trials, with mild to moderate adverse events. TB-500 itself has no published human safety trials, and product quality varies outside pharmacies. People with a history of cancer should talk to a clinician first.
What is the TB-500 dosage?
There is no FDA-approved dose, and no human dose has been published: FDA found no clinical studies of TB-500 in people in its July 2026 review. Online dosing charts are not based on human trials. Your clinician sets any dose.
TB-500 vs BPC-157: what is the difference?
TB-500 is a fragment of thymosin beta-4 and is studied mainly for cell movement and new blood vessels. BPC-157 comes from a stomach protein and is studied for blood supply, growth signals and gut protection. No study has tested the two together, so a clinician should decide whether either, or both, makes sense.
Is TB-500 FDA approved?
No. TB-500 is not FDA-approved for any use. Since October 29, 2026, FDA allows 503A compounding pharmacies to prepare it for individual patients with a prescription, under enforcement discretion, while final rulemaking is pending.
Is TB-500 legal in the US?
A licensed prescriber can now order compounded TB-500 from a 503A pharmacy for a specific patient. Vials sold online as "research use only" are not made for people and are not covered by FDA’s October 2026 policy.
Is TB-500 banned in sports?
Yes. WADA prohibits thymosin beta-4 and its derivatives, including TB-500, and anti-doping labs have published methods to detect it.
Can I get TB-500 through Vitals Vault?
Vitals Vault is opening clinician-led peptide care that starts with a blood test. Join the peptides waitlist to hear first. A licensed clinician reviews your history and labs and decides whether TB-500 is right for you.
Peptides, prescribed and measured
Vitals Vault is opening peptide care that starts with your blood work, is prescribed by licensed US clinicians and ends with a retest. Join the waitlist to hear first.
- Prescription only
- Licensed US clinicians
- Quest Diagnostics labs
Keep reading
Full Peptide Guide- BPC-157A 15-amino-acid peptide from a stomach protein, studied for tendon, muscle and gut repair.
- BPC-157 vs TB-500How the two most popular recovery peptides differ, and why people take them together.
- MOTS-cA peptide coded in your mitochondrial DNA, studied for insulin sensitivity, weight and exercise capacity.
- FDA peptide update 2026What FDA’s October 2026 decision on six peptides means for you.
- Thymosin beta-4The full 43-amino-acid repair protein behind TB-500, tested in eye, skin and heart trials.
Sources
- 1. FDA. Briefing document, Pharmacy Compounding Advisory Committee meeting, July 23 to 24, 2026: TB-500-related bulk drug substances (opens in a new tab)
- 2. Goldstein AL, Kleinman HK. Advances in the basic and clinical applications of thymosin β4. Expert Opin Biol Ther. 2015 (opens in a new tab)
- 3. Esposito S, et al. The N-terminal acetylated 17–23 fragment of thymosin beta 4 identified in TB-500. Drug Test Anal. 2012 (opens in a new tab)
- 4. Ho EN, et al. Doping control analysis of TB-500, a synthetic version of an active region of thymosin β4. J Chromatogr A. 2012 (opens in a new tab)
- 5. Safer D, et al. Thymosin beta 4 and Fx, an actin-sequestering peptide, are indistinguishable. J Biol Chem. 1991 (opens in a new tab)
- 6. Philp D, et al. The actin binding site on thymosin beta4 promotes angiogenesis. FASEB J. 2003 (opens in a new tab)
- 7. Kleinman HK, et al. Thymosin β4 and the anti-fibrotic switch. Int Immunopharmacol. 2023 (opens in a new tab)
- 8. Kassem KM, et al. Tβ4-Ac-SDKP pathway: any relevance for the cardiovascular system? Can J Physiol Pharmacol. 2019 (opens in a new tab)
- 9. Cha HJ, et al. Role of thymosin beta4 in tumor metastasis and angiogenesis. J Natl Cancer Inst. 2003 (opens in a new tab)
- 10. Bock-Marquette I, et al. Thymosin beta4 promotes cardiac cell migration, survival and cardiac repair. Nature. 2004 (opens in a new tab)
- 11. Sosne G, et al. RGN-259 (thymosin β4) eye drops in neurotrophic keratopathy: phase III trial. Int J Mol Sci. 2022 (opens in a new tab)
- 12. Treadwell T, et 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 (opens in a new tab)
- 13. Zhang Y, 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 (opens in a new tab)
- 14. Ruff D, et al. Intravenous thymosin beta4 in healthy volunteers: phase I. Ann N Y Acad Sci. 2010 (opens in a new tab)
- 15. Wang X, et al. Phase I study of recombinant human thymosin β4 in healthy volunteers. J Cell Mol Med. 2021 (opens in a new tab)
- 16. NCPA. FDA grants enforcement discretion for compounding six peptides. October 29, 2026 (opens in a new tab)
- 17. FDA. Certain bulk drug substances for use in compounding that may present significant safety risks (current as of April 22, 2026) (opens in a new tab)
- 18. FDA. Bulk drug substances used in compounding under section 503A (opens in a new tab)
- 19. World Anti-Doping Agency. Prohibited List (opens in a new tab)