What Is TB-500 (Thymosin Beta-4)?

TB-500 is a synthetic seven-amino-acid peptide copied from the actin-binding region of thymosin beta-4, a 43-amino-acid peptide your body makes naturally. The two are not the same substance. Full-length thymosin beta-4 has been tested in human trials, mostly as eye drops and wound gels, with mixed results and no FDA approval. TB-500 itself has no published human studies at all: in its 2026 review, the FDA found no clinical trials, no human safety data, and no animal toxicity studies. As of September 2026, TB-500 is not FDA approved, is not on the list of substances pharmacies may compound, and is banned in sport.

TB-500 and thymosin beta-4 are not the same thing

Most of what you read online about TB-500 treats it as another name for thymosin beta-4. It is not, and the difference is the single most important thing to understand before you evaluate any claim about it. Nearly every study quoted in TB-500 marketing was done with the full-length natural peptide, not with the short fragment that is actually sold under the TB-500 name.

What thymosin beta-4 is

Thymosin beta-4 is a small peptide, a short chain of 43 amino acids. It was first isolated from calf thymus tissue and was originally thought to be a thymus hormone. Later work showed it is made by many cell types throughout the body and is present in blood, plasma, saliva, tears, and wound fluid. Reviews by the scientists who developed it describe it being released by platelets, macrophages, and other cells at sites of injury.

Inside cells, its main job is managing actin, the protein that forms the internal scaffolding cells use to hold their shape and to move. That role is the basis for nearly every healing claim made about it, and it is explained in the next section.

What TB-500 is

According to the FDA's 2026 evaluation, TB-500 is understood to be a synthetic peptide of seven amino acids: leucine, lysine, lysine, threonine, glutamic acid, threonine, and glutamine, written LKKTETQ. That sequence matches positions 17 to 23 of thymosin beta-4. TB-500 also carries an added acetyl group on its first amino acid, a small chemical cap that the natural sequence at that position does not have.

The fragment was first made and tested by researchers in 2003. A veterinary product called TB-500 appeared around 2011 and was marketed to boost performance in racehorses and greyhounds. Anti-doping laboratories in Hong Kong and Belgium analyzed the product in 2012 and confirmed that its key ingredient was the acetylated seven-amino-acid fragment, not the full 43-amino-acid peptide.

TB-500 is a trade name, not an official drug name. The FDA notes that it has encountered multiple salts and derivatives, including entirely different active molecules, sold commercially under the same name. So a vial labeled TB-500 may contain the seven-amino-acid fragment, a salt form of it, or something else, and the label alone will not tell you which.

Why the distinction matters

A fragment of a peptide does not automatically do what the whole peptide does. Thymosin beta-4 has several activities that researchers have mapped to different stretches of its sequence, and TB-500 contains only one of those stretches. The FDA states the point bluntly in its review: several websites use the two names interchangeably, but thymosin beta-4 and TB-500 are not the same substance.

How thymosin beta-4 works in the body

Actin binding and cell migration

Actin exists in two forms. Single units, called G-actin, float freely in the cell. When the cell needs structure or movement, those units link into long filaments, called F-actin. A cell crawling toward a wound is constantly building filaments at its front edge and taking them apart at the back.

Thymosin beta-4 binds to the single G-actin units and holds them in reserve, a function scientists call sequestering. This gives the cell a ready pool of building blocks it can draw on quickly. The FDA's scientific summary describes this buffering as essential to the lengthening of actin filaments and to maintaining the cell's internal skeleton, which in turn affects cell shape, movement, and signaling.

In laboratory experiments this shows up as faster cell migration. In one 1999 study, skin cells called keratinocytes showed 2 to 3 times as much migration in a standard laboratory test when tiny amounts of thymosin beta-4 were added. Better migration of skin, blood vessel, and corneal cells into a wound is the core idea behind its proposed use in healing.

Other proposed actions

Beyond actin, researchers have reported several other effects of full-length thymosin beta-4 in cell and animal studies. These are laboratory findings, not proven effects in people:

• New blood vessel growth (angiogenesis). Treated wounds in rats showed more new vessels, and mouse heart studies identified thymosin beta-4 as important for coronary vessel development.
• Less inflammation. In mouse eyes injured with alkali, treated corneas had fewer inflammatory white blood cells and lower levels of several inflammatory signaling molecules.
• Cell survival. In mouse heart cells, thymosin beta-4 formed a complex with a protein called integrin-linked kinase and switched on Akt, an enzyme that helps cells resist dying after injury.
• Progenitor cell activation. In mice, it appeared to reawaken cells in the outer layer of the heart that can form new vessel cells.
• Less scarring. Reviews by its developers report fewer scar-forming cells, called myofibroblasts, in treated wounds.

Some of these effects may not come from the actin-binding region at all. For example, a four-amino-acid cleavage product of thymosin beta-4 known as Ac-SDKP (serine, aspartic acid, lysine, proline) has been linked to blood vessel formation in mouse heart studies. That sequence does not appear anywhere in TB-500. This is one concrete reason that results from the whole peptide cannot simply be assumed for the fragment.

Does the TB-500 fragment keep the activity?

This is an open question, and the limited data point in different directions. It has been hypothesized that because the LKKTETQ sequence contains the actin-binding region, it may buffer G-actin the way the full peptide does. In a 2003 study from the National Institutes of Health, a non-acetylated version of the seven-amino-acid fragment, applied directly to skin wounds in aged mice, promoted repair about as well as full-length thymosin beta-4.

But TB-500 is the acetylated version, and the FDA cautions that acetylation changes a peptide's charge, size, and binding behavior, so results from the non-acetylated fragment cannot be directly applied to it. In a 2024 study from a Korean anti-doping laboratory, TB-500 itself did not speed wound closure in cultured fibroblasts (connective tissue cells) compared with a control solution. One of its breakdown products, a five-amino-acid piece, did show a small but statistically significant effect. The authors suggested that any wound-healing activity credited to TB-500 may actually come from that metabolite.

That was a single cell-culture experiment with one concentration, so it settles nothing. The honest summary is that nobody has shown, in a living animal or a person, that injected TB-500 does what full-length thymosin beta-4 does. The FDA's review concluded that laboratory evidence to support wound healing with TB-500 is currently lacking.

What animal and laboratory studies of thymosin beta-4 show

The preclinical record for full-length thymosin beta-4 is genuinely interesting, and it explains why serious researchers and companies spent two decades trying to turn it into a drug. Every study in this section used the full 43-amino-acid peptide in animals, not TB-500 and not people.

Skin wounds

The founding study was published in 1999 by National Institutes of Health researchers. In rats with full-thickness skin wounds, thymosin beta-4 applied to the wound or injected into the abdomen increased re-epithelialization, the regrowth of the skin's surface layer, by 42% over saline at 4 days and by as much as 61% at 7 days. Treated wounds also contracted at least 11% more than controls by day 7 and showed more collagen and more new blood vessels.

A 2003 follow-up tested models of impaired healing. In diabetic mice, treated wounds showed significantly more contraction and collagen. In 26-month-old mice, which heal slowly, thymosin beta-4 increased skin cell migration, wound contraction, and collagen deposition. These are the experiments in which the non-acetylated seven-amino-acid fragment was also tested.

The heart

In a 2004 paper in Nature, mice whose coronary artery had been tied off to mimic a heart attack had better early survival of heart muscle cells and improved heart function when treated with thymosin beta-4. Two later Nature papers from a British group, in 2007 and 2011, reported that thymosin beta-4 was essential for coronary vessel development in mice, and that priming adult mouse hearts with it allowed a resident population of progenitor cells to contribute new heart muscle cells after an induced heart attack.

These findings generated real excitement, but they have not yet produced a human treatment. A United States phase 2 trial of injectable thymosin beta-4 after heart attack was registered and then withdrawn; the registry entry says it was never initiated. A Chinese company has registered phase 1 studies in healthy volunteers and phase 2 studies in heart attack patients, but as of September 2026 no results from them are posted on ClinicalTrials.gov. A 10-patient pilot study in China used thymosin beta-4 only to pretreat patients' own cells in the laboratory before transplanting them, which is a different thing from giving the peptide to patients.

The eye

In a 2002 study, mouse corneas burned with alkali were treated twice daily with thymosin beta-4 drops or salt solution. Treated corneas regrew their surface layer faster at every time point and had less inflammatory cell infiltration at 7 days. This work led directly to the eye-drop trials described below, which are the most advanced human testing thymosin beta-4 has received.

Why animal results often do not carry over

Laboratory wounds are small, fresh, and uniform. Human chronic wounds, dry eye, and heart attacks involve older tissue, other diseases, medications, and wide person-to-person variation, and doses, routes, and timing differ too. That gap is why human trials are required. As the next section shows, thymosin beta-4 has followed this familiar pattern: strong animal data, then modest and inconsistent human results.

What human trials of thymosin beta-4 have found

Full-length thymosin beta-4 has been given to people in several company-sponsored trials. None of these used TB-500, and none involved the under-the-skin injections for muscle, tendon, or joint injuries that TB-500 is marketed for. There are no published human trials of any thymosin beta-4 product for tendon, ligament, or muscle injury.

A safety study in healthy volunteers

In a phase 1 study published in 2010, four groups of 10 healthy volunteers each received a single intravenous dose of synthetic thymosin beta-4 or placebo, at 42, 140, 420, or 1,260 mg. After a safety review, they received the same dose daily for 14 days. Side effects were infrequent and mild or moderate, and there were no serious adverse events or dose-limiting toxicities.

This is reassuring about two weeks of a pharmaceutical-grade product under medical supervision. It says nothing about long-term use, about products of uncertain quality, or about TB-500.

Chronic skin wound trials

Three phase 2 trials tested a thymosin beta-4 gel applied once daily for roughly two to three months, each comparing three strengths of gel with a placebo gel.

Venous stasis ulcers

This trial randomized 73 patients at eight sites in Italy and Poland. The published report judged safety comparable to placebo and suggested that the 0.03% strength might speed healing, with complete healing within 3 months in about 25% of patients, mainly those with smaller or milder wounds. The results posted on ClinicalTrials.gov show why this was not a clear win: by day 84, wounds had closed in 12 of 55 patients on any strength of thymosin beta-4 (22%) and in 4 of 17 on placebo (24%).

Pressure ulcers

This 72-patient trial was designed primarily to assess safety. Posted results show healed wounds at day 84 in 8 of 54 patients on thymosin beta-4 (15%) and 3 of 18 on placebo (17%).

Epidermolysis bullosa

This trial in a rare inherited blistering disease was stopped early after enrolling 30 patients; the registry cites lack of available patients and expiration of the study drug. Wounds healed in 8 of 22 patients on thymosin beta-4 and 5 of 8 on placebo, a difference that was not statistically significant.

A 2012 review by the developers reported that in the venous and pressure ulcer trials, thymosin beta-4 sped healing by almost a month among the patients who did heal. That is a secondary analysis of a subgroup, which is useful for planning a next trial but is not proof of benefit. No phase 3 wound trial followed, and a later trial of the gel in epidermolysis bullosa was terminated after 4 patients for business reasons.

Dry eye trials

A thymosin beta-4 eye drop, code-named RGN-259, went furthest. Two small phase 2 studies came first. In one, 72 people with moderate to severe dry eye used 0.1% drops or placebo for 28 days. Neither primary endpoint, ocular discomfort or staining of the lower cornea, differed significantly between groups, although some secondary measures did, including a 27% reduction in discomfort during a dry-air challenge on day 28. No adverse events were reported. In the other, 9 patients with severe dry eye were treated for 28 days; the treated group had 35.1% less discomfort and 59.1% less corneal staining than the placebo group at day 56, but with so few patients the result was only a signal.

Three larger trials followed, named ARISE-1, ARISE-2, and ARISE-3, enrolling 317, 601, and 700 patients. The posted results for ARISE-3, the largest, are clear. On a 0 to 4 staining scale, the average change was a drop of 0.41 points with thymosin beta-4 and 0.46 with placebo. On a 0 to 5 discomfort scale, both groups improved by 0.4 points. In ARISE-2, the posted average changes on the two primary measures were within about a tenth of a point of each other in the drug and placebo groups, and the registry entry posts no statistical comparison. Safety looked acceptable, with no serious adverse events in ARISE-3, but the drops did not beat placebo on the main measures, and no dry eye approval has followed.

Neurotrophic keratopathy trials

Neurotrophic keratopathy is a rare condition in which a cornea with damaged nerves fails to heal. In the SEER-1 phase 3 trial, patients used 0.1% thymosin beta-4 drops or placebo five times a day for 4 weeks. The trial planned to enroll 46 patients but stopped after 18 because recruitment was so slow. Complete healing at 4 weeks occurred in 6 of 10 treated patients and 1 of 8 on placebo. That looks large, but with so few patients it did not reach statistical significance on the planned test (p = 0.0656). At day 43, two weeks after treatment ended, 5 of 10 treated patients and none of 8 placebo patients were healed (p = 0.0359).

A larger European phase 3 trial, SEER-3, was meant to confirm this. In June 2025 the sponsor announced that it failed to show a statistically significant difference from placebo in complete corneal healing at 4 weeks, which a company spokesperson attributed to a stronger-than-expected placebo response. That comes from a company announcement covered in the trade press; no peer-reviewed report of SEER-3 was found. A second United States trial, SEER-2, with a planned enrollment of 70, was still listed as recruiting on ClinicalTrials.gov when this article was written.

What the human record adds up to

The pattern is consistent. Full-length thymosin beta-4 has looked safe in short, supervised trials when applied to the skin or eye or infused for two weeks. It has produced hints of benefit in small studies and has then failed to beat placebo convincingly in larger ones. After roughly 20 years of development, it has not been approved for any condition.

What is known about TB-500 itself in humans

Almost nothing. In the evaluation it prepared for a July 2026 advisory committee meeting, the FDA searched PubMed, Embase, ClinicalTrials.gov, and other databases and reported that it found no articles in which TB-500 was administered to humans. It found no clinical studies of effectiveness, no human studies of how the body absorbs and clears it, and no clinical studies assessing safety by any route. The pharmacy that originally nominated TB-500 for compounding cited three supporting papers, and the FDA noted that none of them was a study of TB-500 given to humans.

What does exist comes from anti-doping science. When racing chemists gave 10 mg of TB-500 under the skin to thoroughbred horses, blood levels peaked between 60 and 120 minutes and became too low to measure between 6 and 10 hours. The peptide was broken down into a series of shorter pieces by stepwise loss of amino acids from its tail end. In rats, the 2024 Korean study found one short breakdown product still detectable in urine at 72 hours. These studies were designed to catch cheating, not to establish benefit, and they tell you nothing about whether the peptide heals anything.

The FDA also reported that it could identify no animal toxicity studies of TB-500 of any kind: no single-dose toxicity studies, no repeat-dose studies, no tests for genetic damage, no reproductive or developmental studies, and no cancer studies. For a conventional drug, much of that testing is expected before or during human trials, starting before the first volunteer receives a dose.

One practical consequence is that there is no evidence-based dose. Every TB-500 dosing schedule published online, including loading phases and maintenance phases, comes from vendor tradition and user forums rather than from a dose-finding study. If you read more about whether there is evidence for combining BPC-157 and TB-500, you will find a similar gap: no human trial has tested the pairing, and the one animal test, a 2026 study in 32 rats with repaired Achilles tendons, found no added benefit from combining them.

FDA status as of September 2026

Not an approved drug

As of September 2026, neither TB-500 nor thymosin beta-4 is FDA approved for any condition. The FDA's review also found no approved TB-500 products in Canada, Australia, the United Kingdom, or the several European countries it checked, and none authorized by the European Medicines Agency.

Compounding: a status that changed in 2026 and is still unsettled

Compounding pharmacies can legally make a drug from a bulk ingredient only if that ingredient meets certain conditions, such as being part of an FDA-approved drug, having an official pharmacopeia monograph, or appearing on an FDA list known as the 503A bulks list. TB-500 meets none of them. The sequence of events matters, because it is often misreported:

1. Category 2. Under an interim policy, the FDA had placed the thymosin beta-4 fragment in Category 2, its group of nominated substances that raise significant safety concerns. The FDA's stated reasons were the risk of immune reactions from peptide clumping and impurities, and the fact that it had identified no human exposure data.
2. Removal in April 2026. The FDA removed the fragment, along with other peptides, from Category 2 because the original nominations had been withdrawn. Legal analysts stressed at the time that removal from Category 2 did not place these substances on the 503A bulks list.
3. FDA staff evaluation. FDA scientists then reviewed TB-500 on the agency's own initiative. Their written conclusion was that the criteria weigh against adding either TB-500 or its acetate salt to the list, citing poor chemical characterization, no evidence of effectiveness, and unknown safety.
4. Advisory committee vote. On July 23, 2026, the FDA's Pharmacy Compounding Advisory Committee voted to recommend adding TB-500 to the list anyway. The tally, 8 to 6 with one abstention, comes from law firm and trade press reports of the meeting; the FDA had not posted official minutes when this article was written.
5. What happens next. The committee's vote is advisory and does not bind the FDA. Adding a substance to the list requires formal notice-and-comment rulemaking. Law firm analyses published after the meeting stated that the peptides were not yet on the list and that the process could extend into 2027 or later.

So, as of September 2026, the accurate statement is this: TB-500 is no longer in the FDA's Category 2, an advisory committee has narrowly recommended allowing it to be compounded, FDA scientists recommended against, and no final decision has been made. Even if TB-500 is eventually added to the list, that would only permit pharmacies to compound it on a prescription. It would not make it an FDA-approved drug or mean the FDA had found it safe or effective. This status is moving quickly, so ask your prescriber what has changed since this article was written.

Research-use-only sellers versus a physician-provided product

The FDA's review found websites selling TB-500 as powder for reconstitution in a range of vial sizes, labeled as intended for research use only. Bought that way, from an anonymous online seller, the product comes with no pharmacy or pharmaceutical oversight, no independent check of what is in the vial, and no one to reconstitute it, set a dose, or follow up. Self-injecting a product like that places every one of those risks on you: the wrong substance, the wrong amount, a non-sterile vial, and no one to call when something goes wrong.

A physician-provided product does not change the evidence described in this article, but it does change what is known about the vial and who is watching the patient. What that route adds is an independent laboratory test of each batch for identity and purity, a certificate of analysis the patient can ask to see, reconstitution in the office rather than at home, written dosing instructions, and medical follow-up. Be clear about the ceiling of that claim: a test for identity and purity confirms that the vial contains what the label says, at the stated purity. It does not make TB-500 an approved drug, supply the missing human data, or answer the safety questions in the next section.

Rx2BFIT does not use a compounding pharmacy. Its TB-500 comes from a supplier whose batches are tested by an independent laboratory for identity and purity, with a certificate of analysis on file, and is reconstituted in the office under Dr. Patel's supervision. It is not an FDA-approved medication, and that, along with the known risks and the limits of the evidence, is reviewed with every patient before starting.

Banned in sport

The World Anti-Doping Agency has named thymosin beta-4 and its derivatives, with TB-500 given as the example, on its Prohibited List since 2018. The entry sits in section S2, which covers peptide hormones and growth factors, and substances in that section are prohibited at all times, both in and out of competition. The 2026 list keeps the same wording. Anti-doping laboratories have validated methods to detect TB-500 and its breakdown products in urine and blood. If you compete in any tested sport, using TB-500 can end your eligibility, regardless of whether a clinician prescribed it. BPC-157 is also prohibited in sport.

Safety unknowns and product quality risks

Marketing often describes TB-500 as having few or no side effects. The accurate version is that side effects have never been systematically measured. The FDA searched its adverse event database through March 2025 and found no reports for TB-500, and it explicitly warned that this proves little: reporting is voluntary and is especially sparse for compounded and gray-market products. A separate FDA complaint database held two reports involving blended TB-500 and BPC-157 products, without enough detail to assess them.

Immune reactions and peptide clumping

The FDA's main stated concern is immunogenicity, meaning the chance that your immune system treats the injected peptide or its contaminants as foreign. Peptides can stick together into clumps, called aggregates, and both aggregates and manufacturing impurities raise that risk. The agency notes that injection routes, including under-the-skin injection, carry particular risk. Possible consequences range from antibodies that cause no symptoms, to loss of any effect, to serious allergic reactions. In theory, antibodies raised against a fragment could also react with the body's own thymosin beta-4. No study has measured how often any of this happens with TB-500.

Purity, identity, and sterility

When the FDA examined the quality paperwork submitted with the TB-500 nomination, the certificate of analysis did not report identity testing, potency, aggregates, or bacterial endotoxin levels, and it allowed individual unidentified impurities of up to 1.0%. The documents also mixed up the chemical identifiers for TB-500 and its acetate salt. The FDA concluded that neither form is well characterized chemically. The lesson for a patient is that a certificate of analysis is only as good as what it reports, so the question is not whether one exists but what it tested.

For you, the practical risks of an injectable product of uncertain quality are the wrong substance, the wrong amount, contamination with bacterial toxins, and infection from a non-sterile product.

The cancer question

Thymosin beta-4 promotes cell migration and new blood vessel growth. Tumors exploit both processes to grow and spread, so researchers have asked whether the peptide could help a cancer along. In a 2003 mouse study in the Journal of the National Cancer Institute, melanoma cells engineered to overproduce thymosin beta-4 formed larger tumors (21.7 mm versus 13.3 mm on average) and far more lung metastases (about 47 nodules versus 11) than control cells, with a roughly fourfold increase in tumor blood vessels.

The picture is not one-directional. In multiple myeloma, a blood cancer, researchers found the opposite: lower thymosin beta-4 levels in cancer cells, longer survival in patients whose cells expressed more of it, and slower disease in mice when the gene was overexpressed.

Both findings concern thymosin beta-4 produced inside cancer cells. Neither tells you what happens when a person injects a fragment of it. No human study has examined cancer risk with thymosin beta-4 or TB-500, and the FDA found no animal cancer studies of TB-500. The risk is theoretical and unmeasured, which is a reason for caution rather than reassurance, especially if you have a current or past cancer.

Pregnancy, breastfeeding, and children

There are no reproductive or developmental toxicity studies of TB-500, and no human data in pregnancy, breastfeeding, or childhood. Thymosin beta-4 is active in embryonic development in mice, including formation of the heart's blood vessels, which makes the absence of reproductive safety data more concerning, not less.

When to seek urgent care

If you have injected any peptide product and develop any of the following, get emergency care and tell the clinicians exactly what you injected:

• Trouble breathing, wheezing, throat tightness, swelling of the face, lips, or tongue, or widespread hives
• Fainting, a racing heartbeat, or severe dizziness shortly after an injection
• Fever, chills, or feeling suddenly very unwell within hours to days of an injection
• Spreading redness, warmth, swelling, severe pain, or pus at an injection site
• Chest pain, new shortness of breath, or sudden weakness or trouble speaking

Myths versus realities

Myth: TB-500 is just synthetic thymosin beta-4

Reality: TB-500 is a seven-amino-acid fragment with an added acetyl group. Thymosin beta-4 has 43 amino acids. The FDA states directly that they are not the same substance.

Myth: it is proven to heal tendons, ligaments, and muscle

Reality: there are no human trials of thymosin beta-4 or TB-500 for any musculoskeletal injury. If you are dealing with a tendon or ligament problem, the treatments with real human evidence are covered in the guide to what studies show for tendon and ligament injuries.

Myth: the FDA approved TB-500 in 2026

Reality: an advisory committee narrowly recommended allowing pharmacies to compound it. That is not approval, the vote is not binding, the FDA's own scientists recommended against, and no final decision had been made as of September 2026.

Who should be especially cautious

Given the absence of human data, caution applies to everyone. It applies with extra force if you are in one of these groups:

• Competitive athletes in tested sports. TB-500 is prohibited at all times, and detection methods exist.
• Anyone with a current or past cancer, or under evaluation for one. The theoretical concern about cell migration and blood vessel growth has never been studied in people.
• Anyone pregnant, trying to conceive, or breastfeeding. There are no reproductive safety data of any kind.
• Children and teenagers. There are no pediatric data.
• People with a history of severe allergic reactions or autoimmune disease. The FDA's central concern with injected TB-500 is an unwanted immune response.
• People with a chronic wound, dry eye, or a corneal condition. These are the conditions where thymosin beta-4 was actually tested. The FDA points out that approved therapies with established effectiveness exist for wound care, and neurotrophic keratopathy has an FDA-approved prescription eye drop. Choosing an unproven injectable fragment over a proven therapy is the riskier path.

If you are exploring peptide therapy more broadly, it helps to sort each peptide by its evidence tier: FDA-approved drugs with large trials at one end, and compounds with only animal or cell data at the other. TB-500 currently sits at the far end of that range, behind even its parent peptide.

Questions to ask your prescriber

If a clinician suggests TB-500, or you are considering asking for it, these questions will quickly show how carefully the recommendation has been thought through:

1. Is the product you are proposing the seven-amino-acid TB-500 fragment or full-length thymosin beta-4, and how do you know?
2. Where does it come from? Who is the supplier, and is the product prepared by a pharmacy or reconstituted in your office?
3. Is each batch tested by an independent laboratory, what does that test cover (identity and purity at a minimum), and can I see the certificate of analysis for my batch?
4. What human evidence supports using it for my specific condition, and was that evidence generated with TB-500 or with thymosin beta-4?
5. How was the dose you are recommending chosen, given that no human dose-finding study exists?
6. What are the proven treatments for my condition, and have I given them a fair trial?
7. How will we decide whether it is working, and when will we stop if it is not?
8. Given my personal and family history, including any cancer history, is there a reason I should avoid it?
9. I compete in a drug-tested sport. What does this mean for me?
10. What should I watch for after an injection, and whom do I reach after hours if something goes wrong?

A prescriber who answers these plainly, including saying "the evidence is not there yet" where that is true, is giving you what you need to make an informed choice. The same questions apply to any product that pairs TB-500 with another peptide, such as the BPC-157 and TB-500 blend.

This is general information, not medical advice. Whether a treatment is right for you is determined by a licensed provider after an evaluation.