TB-500 dosage and evidence

What is TB-500?

How does TB-500 work?

The fragment holds LKKTET, the part of thymosin beta-4 that grabs actin. Actin is a protein that lets cells move and change shape. The idea is that the fragment grabs loose actin the way the parent peptide does. That would help cells move into an injury and help new blood vessels grow there. The FDA's review notes a catch. The wound healing work was mostly done with a version of the fragment without its acetyl cap, or with the full parent peptide. Those results cannot simply be applied to the capped fragment sold as TB-500.

What have studies in people found about TB-500?

No published study has given TB-500 to a person. For its July 2026 review, the FDA searched the main medical and trial databases. It found no study of TB-500 in people by any route, no data on how it moves through the body, and no side effect reports in its database. The human studies quoted in ads were done with thymosin beta-4, the 43 amino acid parent peptide. That is a different molecule with its own page on this site.

• FDA review, July 2026: no study gave TB-500, in either form, to people, for wound healing or anything else. The three papers sent in to support it were all studies of thymosin beta-4, not TB-500. A search of the FDA side effect database through March 26, 2025 found no reports for TB-500.
• First study of the fragment in people: NCT07487363, an early study in 80 people with stable hardening of the arteries, run by Hudson Biotech. It has been signing people up since February 5, 2026. It measures heart blood markers and how well blood vessel linings work. No results yet.
• What it is, found by testing rather than by label: a Ghent University sport drug testing lab found Ac-LKKTETQ in a product sold as TB-500 (2012). The FDA's review gives the same structure, with a molecular weight of 889.01. A TB-500 product for animals appeared in 2011, sold for horses and racing greyhounds.
• The parent peptide, for contrast: thymosin beta-4 has been through an early safety study in 40 healthy adults, given into a vein at 42 to 1,260 mg. It has had three mid-sized skin wound studies and four dry eye studies. Two of those were large studies of 601 and 700 patients, and both missed their main goals. A large study in a rare eye condition, neurotrophic keratopathy, stopped early after 18 patients. A 96-patient study after heart attack compared groups picked by chance. Those numbers are on the thymosin beta-4 page. None of them used the fragment.
• One clinic case in people used thymosin beta-4, not TB-500. In the 2021 Florida knee pain records review, 4 of 16 patients got BPC-157 plus thymosin beta-4, and 3 of those 4 said they got better.

What this does not tell you: For TB-500 itself there is no information in people on dose, how it moves through the body, whether it works or whether it is safe. Results for thymosin beta-4 cannot be assumed to carry over to a seven-piece fragment. The FDA's review goes further. Even the animal wound healing work was mostly done with the uncapped fragment or the full parent peptide. Sellers use the two names as if they were the same. So a person taking a product called TB-500 might be taking either molecule, and user reports cannot be matched to either set of studies. TB-500 is banned in sport and shows up in urine and blood tests.

What do people who took TB-500 report?

This is what real people say happened to them, good and bad. Nobody measured it. A report cannot tell a real effect from the lift people get just from expecting it to work, from a diet or training change made at the same time, or from what was really in the vial. We still put it near the top. It is the next best thing to a study in people: what happens when real people use it, including what goes wrong.

• TB-500 is most often taken with BPC-157, sold and talked about as a healing or wolverine stack. Almost no user report looks at it alone. So nothing people describe can be pinned on this peptide rather than the other one.
• The common plan is a loading phase of a few milligrams a week, split into two shots, for four to six weeks, then a lower dose to keep going. There is no published dose in people. Reviews by bone and joint doctors say plainly that what it is for, the dose, how often and how long are all unknown.
• People say they use it for long-lasting tendon and ligament problems, shoulder and hip trouble, scar tissue and stiffness, and general recovery between hard training blocks.
• People describe slower change than with BPC-157, usually after three to six weeks rather than in the first two. That also makes any change harder to tell apart from the injury healing on its own, or from the rehab done at the same time.
• Problems people mention: no effect at all, cost, feeling tired or flu-like in the first days after a loading dose, and soreness where the needle went in. The FDA has no side effect reports filed under TB-500. One report filed under BPC-157 was for a product with both BPC-157 and TB-500. The person's skin and gums darkened. It went away when they stopped and came back when they started again.
• What is really in the vial is a live argument among users. Buyers compare lab reports and paid purity tests. Some ask straight out whether their vial holds the 43 amino acid peptide or the seven-piece fragment. The FDA's review confirms both are sold under the same name. So it is a fair question, and the label usually cannot answer it.
• If you are tested in sport, TB-500 is a drug testing target. Labs have had published tests for it in urine and blood since the early 2010s.

Sources: FDA's July 2026 evaluation of TB-500, including its FAERS search, its catalogue of vendor claims and its account of the veterinary preparation; the 2012 Ghent doping-control identification paper; the 2026 Sports Medicine and American Journal of Sports Medicine reviews on how these peptides are used and marketed; and public discussion and injury logs on peptide and bodybuilding forums including eroids, iSARMS, Ironsport and FITMISC, where TB-500 is almost always logged alongside BPC-157. Reddit's r/Peptides and r/PeptideSupport could not be retrieved for this entry. No quotation is reproduced from any of these sources and nothing above is attributed to a specific person.

The state of the research

The evidence, in charts

The studies we cite

• Study in people2026
  TB-500 (Thymosin Beta 4 17-23 Fragment) for Cardiovascular Biomarkers in Stable Atherosclerotic Disease (NCT07487363)

  No study of TB-500 in a person has ever been published, and the first one is only now recruiting. It is an early stage trial in 80 adults with stable heart disease, running since February 2026. It is set up to measure blood markers and how well the lining of the blood vessels works, not whether anything heals. No results have been posted. Until they are, every human claim made for TB-500 is borrowed from a different molecule.

  The first registered human study of the fragment itself: Phase 1/2, 80 participants, recruiting since February 2026, endpoints centred on cardiovascular biomarkers and endothelial function. No results posted.

  NCT07487363 ClinicalTrials.gov, Hudson Biotech
• Study in people2018
  Assessment of the Safety and Efficacy of RGN-259 Ophthalmic Solutions for Dry Eye: ARISE-2 (NCT02974907)

  The parent peptide was tested properly for dry eye and it failed. 601 people with dry eye were given either drops containing thymosin beta-4 or the same drops without it, and neither they nor their doctors knew which. After four weeks the two groups came out the same on both of the things the trial was built to measure. TB-500 is a short fragment of this peptide, not the peptide itself, and it has never been through a test like this.

  What the parent peptide's evidence actually looks like: a 601-patient Phase 3 of thymosin beta-4 eye drops whose posted results show no separation from placebo on either co-primary endpoint at day 29.

  This study gave people thymosin beta-4 (full-length, as RGN-259 eye drops), not TB-500. It is here because it belongs on the record, and it is excluded from every count on this page.

  NCT02974907 ClinicalTrials.gov, ReGenTree LLC
• Review of studies2010
  Animal studies with thymosin beta, a multifunctional tissue repair and regeneration peptide

  A review of the animal work on thymosin beta-4, the parent peptide, in skin, eye and heart injuries. In animals it lowered swelling signals and helped cells move, survive and grow new blood vessels. This work led to human studies of the parent peptide, not of TB-500.

  Reviews the animal-model work (dermal, corneal, cardiac) that underpinned thymosin beta-4 clinical trials: reduced inflammatory cytokines, cell migration, angiogenesis and survival.

  PMID 20536453 Annals of the New York Academy of Sciences
• Review of studies2026
  July 23-24, 2026: Meeting of the Pharmacy Compounding Advisory Committee

  The FDA's official record of the July 23, 2026 advisory meeting. TB-500, in both forms, was discussed for the list of ingredients compounding pharmacies may use.

  Official FDA meeting record: TB-500 (free base and acetate) was discussed on July 23, 2026 for possible inclusion on the 503A bulk drug substances list.

  Source U.S. Food and Drug Administration
• Review of studies2026
  FDA Evaluation of TB-500-Related Bulk Drug Substances (TB-500 free base and TB-500 acetate)

  The FDA's review of TB-500. It says TB-500 is a seven-piece fragment of thymosin beta-4, and plainly not the same substance. It found no study giving TB-500 to people by any route, no data on how it moves through the body, and no side effect reports through March 26, 2025.

  Defines TB-500 as the acetylated heptapeptide Ac-LKKTETQ, residues 17 to 23 of thymosin beta-4, molecular weight 889.01, and states plainly that thymosin beta-4 and TB-500 are not the same substance. Found no study administering TB-500 to humans by any route, no human pharmacokinetic data, and no FAERS reports through March 26, 2025.

  Source U.S. Food and Drug Administration, CDER review memorandum, 2026
• Review of studies2026
  Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance

  A review of peptides sold straight to the public for injuries and sport. It lists TB-500 as the fragment and keeps it apart from the parent peptide. It finds good animal repair results are common, but solid safety data in people are rare. It says the dummy pill effect and social media hype push up how well people think these work.

  Reviews the direct-to-patient peptide market, listing TB-500 as the thymosin beta-4 fragment and separating it from the parent peptide. Concludes that favourable animal repair data are common while rigorous human safety data are scarce, and discusses placebo response and social media amplification as drivers of perceived effect.

  PMID 41966639 Sports Medicine
• Animal study2004
  Thymosin beta4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair

  In mice after a blocked heart artery, thymosin beta-4, the parent peptide, helped heart muscle cells survive and the heart pump better. This was not TB-500.

  After coronary artery ligation in mice, thymosin beta-4 upregulated ILK/Akt, enhanced early myocyte survival and improved cardiac function.

  PMID 15565145 Nature
• Animal study1999
  Thymosin beta4 accelerates wound healing

  In rats with deep skin wounds, thymosin beta-4, the parent peptide, sped up healing. New skin covered 42% more by day 4 and up to 61% more by day 7. There was more collagen and more new blood vessels. This was not TB-500.

  In a rat full-thickness wound model, topical or intraperitoneal thymosin beta-4 increased re-epithelialization by 42% at day 4 and up to 61% at day 7, with more collagen deposition and angiogenesis.

  PMID 10469335 Journal of Investigative Dermatology
• Lab (cells in a dish)2012
  Synthesis and characterization of the N-terminal acetylated 17-23 fragment of thymosin beta 4 identified in TB-500, a product suspected to possess doping potential

  In a lab, a Ghent University sport drug testing team checked a product sold as TB-500. They found the seven-piece fragment. Then they made the fragment themselves to build a test for it in blood and urine.

  A Ghent University doping-control laboratory analysed a product sold as TB-500 by high-resolution mass spectrometry and identified the N-acetylated fragment Ac-LKKTETQ, then synthesised it to build a detection method for plasma and urine.

  PMID 22962027 Drug Testing and Analysis