{
  "abstract": "Objective: To describe how people use the unapproved peptides BPC-157 and TB-500 for tendon, ligament and muscle injury and what side effects they report. Methods: Using a large language model validated against physician review, we analyzed 92,254 posts and comments from 28,652 users in Reddit's peptide communities from 2021 to 2026. We compared side effects with those reported by users of four other peptides in the same communities. Results: In all, 5,588 users described using BPC-157 and/or TB-500 for a specific musculoskeletal injury, most often a chronic tendon problem of the shoulder, knee or elbow. Only 3.8% of users described physician involvement, and 90.9% of those naming a source bought from research-chemical vendors. The median BPC-157 dose (366 mcg per injection) was about 2.7 times the human-equivalent dose of the 10 mcg/kg rat regimen, and among new users it rose from 300 mcg in 2024 to 500 mcg in 2025. Of those stating an outcome, 79.3% reported improvement, and 36.6% of all users were also in physical therapy. Overall, 27.2% described at least one side effect, most often fatigue, anxiety, anhedonia and insomnia. Anhedonia was more common than among users of the four other peptides (10.2% versus 1.3% of those with side effects). Conclusion: Use of these unapproved peptides for musculoskeletal injury is largely unsupervised, relying on grey-market products at self-selected, rising doses without established safety or efficacy.",
  "abstract_shown": true,
  "affiliations": [
    "University of Colorado School of Medicine"
  ],
  "article_type": "PUBLISHAHEADOFPRINT",
  "arxiv": null,
  "author_total": 4,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "J. J. Cassinat"
    },
    {
      "name": "C. Callan"
    },
    {
      "name": "C. Liggett"
    },
    {
      "name": "V. Wright"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/6m6664fqszbe0.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.11.04.26367022",
  "fulltext_url": "https://www.medrxiv.org/content/10.64898/2026.11.04.26367022v1.full",
  "id": "6m6664fqszbe0",
  "issns": [],
  "landing_url": "https://www.medrxiv.org/content/10.64898/2026.11.04.26367022v1",
  "language": null,
  "licence": "CC-BY-NC-ND",
  "licence_label": "CC BY-NC-ND",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "medrxiv",
      "sports medicine"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://www.medrxiv.org/content/10.64898/2026.11.04.26367022v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-04",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/6m6664fqszbe0.ris",
  "sources": [
    {
      "first_seen": "2026-11-07T00:20:58Z",
      "native_id": "10.64898/2026.11.04.26367022",
      "source": "medrxiv",
      "url": "https://www.medrxiv.org/content/10.64898/2026.11.04.26367022v1"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "medrxiv:sports medicine",
      "subfield": "general"
    }
  ],
  "title": "Real-World Use, Dosing, and Reported Side Effects of BPC-157 and TB-500 for Musculoskeletal Injury: An Analysis of Online Communities",
  "title_text": "Real-World Use, Dosing, and Reported Side Effects of BPC-157 and TB-500 for Musculoskeletal Injury: An Analysis of Online Communities",
  "type": "preprint",
  "updated_at": "2026-11-08T00:20:58Z",
  "url": "https://research.draconitic.com/paper/6m6664fqszbe0",
  "venue": "medRxiv",
  "versions": []
}