BPC-157 and TB-500 Comparison
BPC-157 vs. TB-500: What the Research Shows
Originally published 9/3/2024 · Updated 10/6/2026
BPC-157 and TB-500 are two research peptides that come up often in conversations about tissue biology. Both are investigational. Neither is FDA-approved for any use, and most of what is known about them comes from laboratory and animal studies. This article explains what each one is, what has been studied, and what remains unknown.
Important
- Neither BPC-157 nor TB-500 is FDA-approved.
- Both were reviewed by the FDA’s Pharmacy Compounding Advisory Committee (PCAC) in July 2026. That was an advisory vote only, and it is non-binding.
- Compounding of these substances remains restricted pending FDA rule-making. Read our FDA Peptide Review.
- Nothing here is medical advice, a recommendation, or a promise of results.
At a Glance
| BPC-157 | TB-500 | Timbetasin (thymosin beta-4) | |
|---|---|---|---|
| What it is | A synthetic 15-amino-acid peptide modeled on a protein sequence found in gastric juice | A synthetic 7-amino-acid fragment of thymosin beta-4 (residues 17–23) | The recommended international name for full-length thymosin beta-4, a naturally occurring 43-amino-acid peptide[2] |
| Proposed mechanism (lab and animal research) | Studied for effects on growth-factor signaling and new blood vessel formation in animal tissue models[1] | Studied for its link to actin binding, a protein involved in cell movement | Studied for actin binding and cell migration in laboratory and eye-tissue models[2] |
| Human evidence | A 2025 systematic review found 36 studies: 35 preclinical and 1 clinical. No human clinical safety data[1] | No published controlled human trials of the fragment that we are aware of | Small human trials, mainly of an eye-drop formulation, not of injections[2][3] |
| FDA status | None of the three is FDA-approved for any use. | ||
Two Names, Often Confused
Online, “TB-500” and “thymosin beta-4” are often treated as the same thing. They are not. Thymosin beta-4 (also called timbetasin) is a 43-amino-acid peptide that occurs naturally in the body. TB-500 is a much shorter, synthetic piece of it: about seven amino acids. Findings about one do not automatically apply to the other, and clinical trials of thymosin beta-4 used the full-length peptide[2][3].
Simplified schematic for illustration only; not drawn to molecular scale. Images are for illustration purposes only.
What the Evidence Can — and Can’t — Tell Us
| What has been found | What is still unknown |
|---|---|
| BPC-157 has been tested in many animal models, with no adverse effects reported in those safety studies[1]. | Whether those results apply to people. The review found no clinical safety data in humans and only low-level (Level IV/V) evidence[1]. |
| Full-length thymosin beta-4 has been tested in a small, randomized eye-drop trial[2]. | The trial had 18 participants and its main comparison was not statistically conclusive. It says little about injections or other uses[2]. |
| Additional thymosin beta-4 eye-drop studies are registered with ClinicalTrials.gov[3]. | Long-term safety, optimal formulation, and quality of products sold as “TB-500.” |
Our Perspective
This section is editorial, not FDA policy. We believe patients are best served by clear information about what is and is not known. If you come across BPC-157, TB-500, or timbetasin from any source, we suggest asking three questions:
- Which exact molecule is in the product? Names are used loosely, as the table above shows.
- Where was it made, and what third-party testing was done?
- What is its regulatory status, and what does the evidence show for the intended use?
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Referenced Research
A 2025 systematic review identified 36 studies of BPC-157 in orthopaedic sports medicine: 35 preclinical (animal or laboratory) studies and 1 clinical study. Animal safety studies reported no adverse effects, but the authors note there is no clinical safety data in humans and that the overall evidence is low level.
Vasireddi N, Hahamyan H, Salata MJ, et al. “Emerging Use of BPC-157 in Orthopaedic Sports Medicine: A Systematic Review.” HSS Journal, published online July 31, 2025. PMC12313605.
A randomized, placebo-controlled, double-masked phase III trial (SEER-1) tested 0.1% thymosin beta-4 (timbetasin acetate) eye drops in 18 patients with neurotrophic keratopathy, a corneal condition. At about four weeks, complete corneal healing occurred in 6 of 10 treated patients versus 1 of 8 on placebo, a difference that did not reach conventional statistical significance (p=0.0656). This was an eye-drop study and does not address injections.
Sosne G, Kleinman HK, Springs C, Gross RH, Sung J, Kang S. “0.1% RGN-259 (Thymosin β4) Ophthalmic Solution Promotes Healing and Improves Comfort in Neurotrophic Keratopathy Patients in a Randomized, Placebo-Controlled, Double-Masked Phase III Clinical Trial.” International Journal of Molecular Sciences, 2023;24(1):554. doi:10.3390/ijms24010554.
A registered phase 2 clinical trial evaluated 0.1% thymosin beta-4 eye drops, dosed twice daily for 28 days, in dry eye. The registry describes thymosin beta-4 as a synthetic copy of the naturally occurring 43-amino-acid peptide.
ClinicalTrials.gov Identifier NCT01387347. Sponsor: ReGenTree. clinicaltrials.gov/study/NCT01387347
Important Disclosures
- This article is for educational purposes only and is not medical advice. These statements have not been evaluated by the U.S. Food and Drug Administration.
- BPC-157, TB-500, and timbetasin (thymosin beta-4) are not FDA-approved for any use. Compounded drugs are not FDA-approved and have not been evaluated by the FDA for safety, effectiveness, or quality.
- The regulatory situation is evolving. The “Our Perspective” section is editorial and does not represent FDA policy.
- Images are for illustration purposes only. Treatment decisions are made solely by an independent, licensed clinician after an individualized evaluation.