Predrag Sikiric

Overview

Predrag Sikirić is a Croatian physician-scientist affiliated with the School of Medicine at the University of Zagreb, known for identifying and systematically studying the pentadecapeptide BPC-157. His research program, spanning more than three decades, has produced an unusually large body of preclinical work on BPC-157 across multiple organ systems, including the gastrointestinal tract, musculoskeletal system, central nervous system, and cardiovascular system.

Sikirić began his career in the 1980s working on gastric cytoprotection — an area championed by his colleague Marin Rogozin and by international researchers such as Andre Robert. In the course of screening gastric juice fractions for protective activity, his group identified the parent "Body Protection Compound" (BPC) and subsequently its active 15-amino-acid fragment, BPC-157. The pentadecapeptide became the focus of his subsequent career.

Sikirić's collaborators include Sven Seiwerth, a pathologist who has contributed histological characterization to most of the Zagreb group's BPC-157 publications, and a rotating cast of pharmacologists, surgeons, and molecular biologists across Croatia and Europe.

Background

Sikirić trained in medicine at the University of Zagreb and developed his research interests in experimental gastroenterology during the 1980s. The Zagreb laboratory approaches BPC-157 through bioassays in rodent models of ulcer, tendon injury, nerve crush, colitis, and cardiac ischemia, among others. The group's preferred delivery routes are often intraperitoneal or oral, with systematic dose-response characterization.

Although Sikirić's body of work is dominantly preclinical, it is exceptionally broad. Publications span effects on nitric oxide signaling, the dopaminergic system, angiogenesis, growth factor receptor expression, collagen synthesis, inflammatory signaling, and gastrointestinal motility. Many of these papers have appeared in specialty pharmacology journals, with occasional coverage in higher-profile outlets.

Key Contributions

• Identification of BPC-157 as a stable fragment of a larger gastric protective protein.
• Systematic preclinical characterization of BPC-157 across ulcer, wound healing, tendon and nerve injury, cardiovascular, and central nervous system models.
• Development of standardized dosing and delivery protocols for rodent studies of BPC-157.
• Long-term mentorship of a generation of Croatian pharmacologists and clinicians.

Timeline

• 1980s: Begins research on gastric cytoprotection.
• Early 1990s: BPC-157 sequence is identified.
• 1993–2000: First wave of preclinical publications on gastric and cardiovascular effects.
• 2000s: Expansion into tendon, ligament, nerve, and brain models.
• 2010s: Growing international interest in BPC-157 as a research peptide.
• 2022: BPC-157 is added to the WADA Prohibited List.

Modern Relevance

BPC-157 has become one of the most widely discussed "research peptides" in sports medicine and regenerative-medicine communities, despite the absence of regulatory approval for any indication. The Zagreb group's body of preclinical work forms the core scientific evidence base for the peptide, and Sikirić's collaborators continue to publish actively.

Because most of this work is preclinical and much of it comes from a single research network, independent replication in other laboratories has been important but limited. Clinicians and researchers assessing BPC-157 generally recognize the depth of the preclinical catalog while noting the comparative scarcity of rigorous, controlled human trials. For broader context, see bpc-157-discovery and wound-healing-research.

Related Compounds

• BPC-157
• TB-500
• Thymosin Beta-4
• Pentadecapeptide
• Growth Hormone Releasing Peptides