TB-500
TB-500 is a lab-made fragment of a protein the body makes. The human trials that exist tested the full protein, not the fragment.
At a glance
Last reviewed October 12, 2026. Regulatory status for these substances has been changing, so we re-check this page and update the date.
What the research shows
Thymosin beta-4 is a protein found throughout the body. Reviews describe it as involved in how tissue responds to injury, based mostly on laboratory and animal research. [1]
Human trials exist, but they tested the full-length protein and were small. A randomized, double-blind trial of topical thymosin beta-4 in 73 people with venous leg ulcers found that it may have the potential to speed wound healing, with about 25% of patients healing completely within three months. [2] A small trial of thymosin beta-4 eye drops (RGN-259) in 9 people with severe dry eye reported less ocular discomfort than the vehicle at day 56. [3] A phase 1 trial of intravenous synthetic thymosin beta-4 in 40 healthy volunteers found it was well tolerated. [4]
TB-500 is different. FDA’s review says its literature search found no articles in which TB-500 was given to humans. [5] A 2026 review of injectable peptides for orthopaedic use also found human orthopaedic data on thymosin beta-4 and TB-500 to be lacking. [6]
What is still unknown
- Whether TB-500 has any effect in people. The trials that exist cannot answer that, because they tested a different molecule.
- Whether it is safe in people, at any dose or route.
- Whether an oral liposomal product delivers TB-500 into the body. We found no studies of that.
Where it stands with FDA and in sport
FDA has not approved any drug that contains TB-500. FDA’s review states that it has not identified human exposure data on drug products containing this fragment. [7]
TB-500 was among the substances considered at FDA’s July 2026 advisory committee on compounding. FDA staff proposed that it not be added to the compounding list. Media reports say the committee voted in favor. The vote is advisory, and we found no final FDA action when this page was reviewed. [8]
The World Anti-Doping Agency’s 2026 Prohibited List names thymosin-beta-4 and its derivatives, such as TB-500, as prohibited. Competitive athletes should not use it. [9]
The product
Quicksilver Scientific Oral Liposomal BPC + TB-500
Quicksilver Scientific sells a combination oral liposomal liquid, 1 mL per serving, 30 mL bottle. Its Supplement Facts panel lists “BPC (as Pentadeca Short Chain Amino Acids)” at 1,000 mcg and TB-500 at 1,000 mcg per serving.[10]
It is sold as a dietary supplement, not an FDA-approved drug. We are not aware of published human studies of TB-500, of BPC-157 taken by mouth, or of this combination.
Quicksilver does not sell TB-500 on its own.
If you are curious about this product, talk with a KOI clinician first. We review your history, your medications and your labs, and we will tell you plainly what is known and not known.
Sources
- Goldstein AL, et al. Thymosin β4: a multi-functional regenerative peptide. Basic properties and clinical applications. Expert Opin Biol Ther. 2012. PMID 22074294
- Guarnera G, et al. The effect of thymosin treatment of venous ulcers. Ann N Y Acad Sci. 2010. PMID 20536470
- Sosne G, et al. Thymosin beta 4 ophthalmic solution for dry eye: a randomized, placebo-controlled, phase II clinical trial conducted using the controlled adverse environment (CAE) model. Cornea. 2015. PMID 25826322
- Ruff D, et al. A randomized, placebo-controlled, single and multiple dose study of intravenous thymosin beta4 in healthy volunteers. Ann N Y Acad Sci. 2010. PMID 20536472
- U.S. Food and Drug Administration. Pharmacy Compounding Advisory Committee, July 23–24, 2026: FDA briefing document on TB-500
- Mayfield CK, et al. Injectable Peptide Therapy: A Primer for Orthopaedic and Sports Medicine Physicians. Am J Sports Med. 2026. PMID 41476424
- U.S. Food and Drug Administration. Certain bulk drug substances for use in compounding that may present significant safety risks (content current as of April 22, 2026)
- U.S. Food and Drug Administration. July 23–24, 2026 Pharmacy Compounding Advisory Committee meeting page
- World Anti-Doping Agency. 2026 Prohibited List, as published in the Dutch Treaty Series (Trb. 2026, 25), class S2.3
- Quicksilver Scientific. Oral Liposomal BPC + TB-500 (product page)
Good to know
Is TB-500 the same as thymosin beta-4?
Is TB-500 allowed in competitive sport?
Explore the Ēnel Health Peptide Atlas
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