Injectable Peptide Therapy: A Primer for Orthopaedic and Sports Medicine Physicians.

BACKGROUND: Therapeutic peptides are short-chain amino acids that regulate cellular functions and facilitate biochemical processes. In recent years, there has been significant growth in the global market for therapeutic peptides and thus its popularity among patients. Given the increase in the development of peptides and increased marketing to patients for orthopaedic injuries, it is critical for orthopaedic surgeons to understand the current evidence behind these therapeutic peptides. PURPOSE: To evaluate the current evidence and applications of injectable peptide therapy, focusing on its potential in regenerative medicine and sports performance, to help orthopaedic providers better understand the current state of different therapeutic peptide approaches. STUDY DESIGN: Narrative review. METHODS: A comprehensive literature search was conducted using PubMed to identify biochemical and clinical studies on the most popular types of injectable peptide therapy. Key peptides evaluated included BPC-157, TB-4, TB-500, CJC-1295 + ipamorelin, tesamorelin, and GHK-Cu. RESULTS: BPC-157 demonstrated potential benefits in tendon and muscle repair, but these findings are largely unvalidated in human trials. A single human case series reported improvements in pain after intra-articular knee injections of BPC-157, although significant methodological flaws and a lack of controls limit its applicability and reliability. TB-4 and its derivative TB-500 promoted angiogenesis and tissue repair in preclinical models, but human orthopaedic data are lacking, and both remain banned substances in sports. CJC-1295 combined with ipamorelin showed significantly improved maximum tetanic tension in murine models with glucocorticoid-induced muscle loss, but these findings are limited to animal studies. Tesamorelin, approved for treating HIV-associated lipodystrophy, has no supporting orthopaedic evidence. GHK-Cu showed promise in wound healing and anti-inflammatory effects, but no clinical data support its use for musculoskeletal conditions. CONCLUSION: While peptide therapy may possess significant therapeutic and regenerative potential, it is critical that orthopaedic and sports medicine providers understand the current lack of evidence to support the clinical use of these peptides. Importantly, information regarding the indications, dosing, frequency, and duration of treatment remains unknown. Despite the popularity of these peptides in mainstream media and among patients, significant research regarding the safety and efficacy of these therapeutic methods is required before definitive recommendations can be made to patients.