BPC-157 and TB-500: what the research says

No controlled human trial has tested BPC-157 and TB-500 together. Each has been studied on its own, mostly in animals: BPC-157 has five small human studies, and the FDA found no published report of TB-500 given to people at all. Neither is FDA-approved, and WADA bans both in sport.

The only human report that involves both kinds of peptide is a look-back chart review of 4 knee patients, and they received thymosin beta-4, not TB-500. If you’re checking the arithmetic on a two-peptide vial label, the blend calculator shows how much of each peptide a syringe reading holds, from the mg printed for each; it does no dosing.

Two different peptides, side by side

Sources: FDA BPC-157 briefing; FDA TB-500 briefing; NCT07437547; NCT07487363; WADA. All checked October 16, 2026.

TB-500 is not thymosin beta-4

Many websites use the two names as if they were one. The FDA doesn’t: “Several websites state that TB-500 is a synthetic version of thymosin beta-4 and often use the terms interchangeably. However, as noted previously, thymosin beta-4 and TB-500 are not the same substance” (FDA TB-500 briefing, section II.B).

That matters when you read the research. Thymosin beta-4, the full protein, “has been used successfully in several clinical trials involving tissue repair and regeneration,” in the words of a 2015 review, which described trials as “ongoing and projected” in eye injuries, skin wounds, heart repair after a heart attack and the brain (Goldstein et al., 2015). Those studies tested the 43-amino-acid protein. They say nothing direct about a 7-amino-acid fragment.

The evidence for BPC-157 on its own

In animals. A 2025 systematic review screened 544 articles and included 36 studies: 35 preclinical and 1 clinical. In animal models, BPC-157 “improved functional, structural, and biomechanical outcomes in muscle, tendon, ligament, and bony injuries,” but “No clinical safety data were found” (Vasireddi et al., 2025). The FDA adds that “dose-response relationships ... have not been established” and that its “mechanisms of action ... remain poorly understood” (FDA BPC-157 briefing).

In people. The five studies the FDA counted used an enema (two studies), a knee injection, a bladder injection and an IV drip in 2 healthy adults. The FDA’s verdict: “these studies were of short duration, had small sample sizes, evaluated doses that were likely exploratory in nature, and the authors provided limited information on safety data.” The first placebo-controlled trial of BPC-157 injected under the skin, in 120 people with hamstring strains, has been recruiting since February 2026 and has posted nothing yet (NCT07437547). How these routes compare is covered in BPC-157 oral vs injection.

The evidence for TB-500 on its own

In people. “After conducting a literature search, no articles were found in which TB-500 was administered to humans” (FDA TB-500 briefing, section II.B). The first registered human trial is a phase 1/2, placebo-controlled study of 80 adults with stable atherosclerotic heart disease in China. It has been recruiting since February 2026, and its main outcomes are side effects (NCT07487363).

In animals and the lab. The FDA found no animal study of whether TB-500 helps wounds heal. It did find a lab study in which TB-500 “did not induce wound healing in confluent cultures of fibroblasts with scratch-generated wounds,” though one of its breakdown products “appeared to have wound-healing properties in vitro.” The FDA found no toxicity studies. Injected under the skin or into the abdomen in animals, TB-500 “reaches the systemic circulation and is metabolically hydrolyzed into smaller peptides” (section III.4).

FDA conclusion. “FDA is particularly concerned about the absence of human data on drug products containing these substances administered via any route of administration,” and injected peptides “may pose a significant risk for immunogenicity, potentially amplified by aggregation as well as potential peptide-related impurities.” Staff proposed “not adding TB-500 (free base) or TB-500 acetate to the 503A Bulks List” (section III).

What’s known about the two together

Everything on record fits in three items:

• A knee chart review (2021). At one Florida clinic, 4 patients received BPC-157 with “TB4” (thymosin beta-4, not TB-500), and “75% showed significant improvement.” The authors note “No specific tools were used to measure their improvement,” and there was no comparison group (Lee & Padgett, 2021).
• One FDA adverse event report. A product containing BPC-157 and TB500, labeled “research purposes only,” was linked to “diffuse hyperpigmentation and gingival darkening” that came back when the product was taken again and stopped after it was discontinued. The FDA: “because the product contained two peptides it is not possible to assess a potential relationship between BPC-157 and the reported AEs” (FDA BPC-157 briefing, section II.D.2.b).
• Two cases in an FDA complaint database. The FDA’s search of its HFCS database “retrieved two cases about ‘blended TB-500 and BPC-157’; however, the reports did not include safety assessments” (FDA TB-500 briefing).

None of this tests whether the two do anything together. A 2026 review covering both peptides warns that “rigorous human safety data are scarce, and there is potential for serious harm to patients,” and discusses “the placebo effect as a mediator of peptide efficacy, and how social media amplifies this effect” (Sports Med, 2026).

Regulatory status of both

• FDA approval: neither is approved for any use (FDA BPC-157 briefing; FDA TB-500 briefing).
• Category 2: as of April 2026, both nominations had been withdrawn from the FDA’s Category 2 safety-risk list. For TB-500 the FDA wrote that it “has not identified any human exposure data” and “lacks important information regarding any safety issues raised by this drug” (FDA).
• Advisory committee, July 2026: both were on the July 23 agenda as substances “being considered for inclusion on the 503A Bulks List,” and FDA staff proposed not adding either. The committee narrowly voted to recommend adding both, although FDA staff had unanimously opposed adding any of the peptides under review (ABC News, 2026). The FDA notes that “Advisory committees make non-binding recommendations to the FDA, which generally follows the recommendations but is not legally bound to do so” (FDA). As of October 16, 2026, the FDA had published no proposed or final rule on either; that rulemaking step “can take up to a year” (ABC News, 2026).
• Sport: BPC-157 is banned at all times under S0, and “Thymosin-ß4 and its derivatives e.g. TB-500” under S2.3, also at all times. A blend therefore contains two prohibited substances (WADA).

For what happens next, see peptide regulation.

Reading a blend vial label

A two-peptide vial is arithmetic, not evidence. The blend calculator takes the mg printed for each peptide and the water you add, and shows how much of each sits in a given syringe reading; mixing peptide blends explains the math. Three things the label can’t tell you:

• Which form it holds. The FDA treats BPC-157 free base and BPC-157 acetate, and TB-500 free base and TB-500 acetate, as “different active pharmaceutical ingredients.” A label that just says “BPC-157” may not say which.
• Whether the contents match. For TB-500 the FDA says tests “for impurities, aggregates, microbiological quality, and bacterial endotoxin” are “not available in the public domain” (section III.1). No regulator has checked what is in these vials.
• How long it lasts once mixed. No official or validated in-use period exists for either peptide, alone or blended. See how long reconstituted peptides last.

Questions people ask