Healing Peptides (BPC-157 / TB-500) Drug-Drug Interaction Table

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Is there an interaction table for these peptides?

No. An interaction entry needs human exposure data: how much drug reaches the blood, how quickly it is cleared, and what it does to the enzymes and transporters that handle other drugs. For TB-500, none of that exists. FDA's reviewers searched PubMed, Embase, ClinicalTrials.gov and other databases and found no human pharmacokinetic or pharmacodynamic data by any route, so its clearance in people has not been measured [1].

That leaves nothing to tabulate. A row saying a peptide is predicted to interact with warfarin or an SSRI would be a guess, not a finding.

What is known about TB-500 in the body

Animal data indicate that TB-500 given subcutaneously or intraperitoneally reaches the bloodstream and is broken down into smaller peptides; FDA found no animal study using the intramuscular route [1].

No nonclinical toxicity studies of TB-500 were found, and no study of its immunogenicity or aggregation, which is FDA's stated safety concern for an injectable peptide [1].

FDA's adverse-event database search through 26 March 2025 retrieved no TB-500 reports. Its food and supplement complaint system (2004 to 2025) retrieved two cases about a blended TB-500 and BPC-157 product with no safety assessment attached, and no published case reports were found [1]. Safety in humans is unknown.

What is known about BPC-157 in humans

BPC-157 is the stable gastric pentadecapeptide GEPPPGKPADDAGLV, molecular weight about 1419, studied in rats for GI lesions, ligament healing and wound repair [3][5]. In a retrospective chart review at one Florida clinic, 16 patients were reached by phone after intra-articular peptide injections: 12 had BPC-157 alone and 4 had BPC-157 plus thymosin beta-4. Of those 4, 75% reported significant improvement, against 11 of 12 on BPC-157 alone. There was no control group, no validated measurement tool, and patients were recalling results, so the review cannot show that either peptide works [2].

The one case report involving both peptides together

FDA's BPC-157 review describes a 40-year-old woman who used a research-only BPC-157 plus TB-500 product (5 mg/5 mg) injected subcutaneously twice daily and developed widespread skin hyperpigmentation and gum darkening within a week; the reaction recurred when she re-tried the product two weeks later. Because the product contained two peptides, FDA said it could not tell whether either one caused it [4]. It does not identify the responsible peptide.

What animal findings do and do not show

Rat work on BPC-157 describes interaction with the nitric oxide system (both L-arginine and L-NAME effects), strong angiogenic potential, and changes in dopamine and serotonin signalling after peripheral administration [3][6]. These are animal pathway findings. They do not establish the size or direction of any effect in a person who also takes another drug.

Full-length thymosin beta-4 data do not transfer to TB-500. TB-500 is not thymosin beta-4. It is a synthetic, N-acetylated 7-amino-acid fragment (residues 17 to 23) of the 43-amino-acid protein [1]. FDA found no in-vivo animal study of TB-500 for wound healing, and in an in-vitro scratch-wound test TB-500 at 50 micrograms/mL did not induce wound closure in fibroblast cultures, while a shorter metabolite did show activity [1]. Trials of full-length recombinant thymosin beta-4, including single-dose cohorts of 54 healthy volunteers given intravenous NL005 [7] and 96 STEMI patients after angioplasty [8], tested a different molecule and say nothing about TB-500's interactions.

Why there is no label to check

TB-500 is not an FDA-approved drug. FDA found no USP or National Formulary monograph for it, no approved product containing it, no listing in the European or Japanese pharmacopeias, and no approved product in Canada, Australia, the UK or other countries reviewed, nor any authorized by the European Medicines Agency [1]. It sits in the nominated-but-withdrawn table on FDA's page for bulk substances that may present significant safety risks, and removal from the earlier category 2 table was not a finding that it is safe [9].

In July 2026 FDA staff recommended against adding TB-500 free base or TB-500 acetate to the pharmacy bulks list, citing no human data of any kind and immunogenicity risk from injection; the advisory committee voted the other way on 23 July 2026, and that vote is advice only [1][10]. HHS's October 2026 draft enforcement-discretion policy names TB-500 among six peptides. The notice says it does not establish any rights and is not binding; it is not an FDA approval and does not put TB-500 on any list [11]. BPC-157 was on the same July 2026 committee agenda as a bulk substance for compounding [10].