Who is Predrag Sikirić?

The researcher at the University of Zagreb who has led the BPC-157 research programme across roughly three decades and authored much of its literature.

Does concentrated authorship invalidate the work?

No. It means the evidence is less independent than the volume implies, which is a standard consideration in appraising any literature.

Why does the current trial matter?

It is sponsored by an unconnected party and is randomised, double-blind and placebo-controlled. The independence test the literature has largely lacked.

The Zagreb Group and BPC-157 Research

The short answer

Most BPC-157 research originates from a group at the University of Zagreb led by Predrag Sikirić, spanning three decades and covering gastrointestinal, musculoskeletal and vascular models. That concentration gives the literature depth and limits its independence.

Key facts

Institution: University of Zagreb
Principal investigator: Predrag Sikirić
Span: Roughly three decades
Model organism: Predominantly rat
Range: GI, tendon, ligament, vascular, ocular
Clinical work: PL-14736 for IBD

The scope of the programme

The Zagreb group has published on BPC-157 across an unusually wide range of models, gastrointestinal lesions, fistula healing, tendon and ligament repair, blood vessel effects, and more recently ocular applications. Sikirić's 2011 review in Current Pharmaceutical Design, 2020 work on fistula healing and 2023 paper in Pharmaceuticals map that breadth.

What sustained programmes provide

Continuity and accumulated method. A group that has worked on one molecule for thirty years knows its handling, its assays and its failure modes in ways that cannot be reconstructed from papers. That depth is valuable and it is why the Zagreb literature is the starting point for anyone studying this compound.

Research material referenced

BPC-157 5mg, third-party HPLC tested

Buy BPC-157 · £15.99

The breadth question

A compound reported active in gastrointestinal, musculoskeletal, vascular and ocular models is either pleiotropic or is being tested by a group with a strong prior. Both are possible and they are not mutually exclusive. Breadth of reported activity is a reason for interest and also a reason for caution, because compounds that appear to work in everything have a poor historical record.

Why independent replication matters here specifically

Shared reagents, shared assays and shared assumptions propagate through a single group's output in ways that are invisible in any individual paper. Replication by unconnected investigators is what tests for that. For BPC-157 the independent literature is thinner than the total volume suggests, which is the single most useful caveat to carry into reading it.

The trial as an independence test

The Phase 2 trial now recruiting, NCT07437547, is sponsored by Hudson Biotech rather than by the original research group. A randomised, double-blind, placebo-controlled trial run by an unconnected sponsor is exactly the kind of test the literature has lacked, and its result (whichever way it goes) will be more informative than any further preclinical work.

Frequently asked questions

Who is Predrag Sikirić?: The researcher at the University of Zagreb who has led the BPC-157 research programme across roughly three decades and authored much of its literature.
Does concentrated authorship invalidate the work?: No. It means the evidence is less independent than the volume implies, which is a standard consideration in appraising any literature.
Why does the current trial matter?: It is sponsored by an unconnected party and is randomised, double-blind and placebo-controlled. The independence test the literature has largely lacked.

Extended research context

The BPC-157 (Pentadecapeptide) deep dive

Deep dive: the pentadecapeptide sequence

BPC-157 is a synthetic pentadecapeptide with the sequence Gly-Glu-Pro-Pro-Pro-Gly-Lys-Pro-Ala-Asp-Asp-Ala-Gly-Leu-Val. It is derived from a fragment identified in human gastric juice by the Zagreb research group (Sikirić and colleagues), whose body of published work spans three decades and covers models ranging from tendon repair to gut integrity. The 'BPC' initials stand for 'body protection compound', the group's original characterisation term.

Two forms: acetate salt vs arginate

BPC-157 is supplied most commonly as an acetate salt; a small subset of suppliers offer the arginate form, which has slightly different solubility and stability properties. For research reproducibility, keep the salt form consistent across a study and confirm which form the CoA specifies (mass ± counterion changes the reading).

Reading a BPC-157 CoA

A trustworthy BPC-157 CoA lists HPLC purity (target ≥98% area), mass-spec confirmation (~1,419 Da for the free peptide), water content (Karl Fischer), acetate content, and residual solvents. Some batches also include endotoxin data. Any missing category is a red flag for a compromised supply chain.

Research applications

▸Cell-culture models of gut epithelial integrity
▸Tendon fibroblast migration and collagen-synthesis assays
▸Angiogenesis models involving VEGF and NO signalling
▸Stability studies comparing acetate vs arginate salt forms
▸Analytical reference for pentadecapeptide HPLC methods

Handling checklist

✓Store lyophilised vial at −20 °C long-term (2–8 °C short-term)
✓Reconstitute with bacteriostatic water; a 5 mg vial dissolves cleanly
✓Aliquot reconstituted solution; keep refrigerated 2–8 °C, use within 28 days
✓Protect from light and repeated warming
✓Verify CoA: HPLC ≥98%, mass ~1,419 Da, salt form declared

Common research-handling mistakes

Learnt from thousands of researcher orders across our UK labs.

✗ Mixing acetate and arginate BPC-157 across a study

Fix: Choose one salt form and stay with it. Different masses and solubility.

✗ Assuming stability at room temperature

Fix: Refrigerate reconstituted solution; discard after 28 days.

✗ Buying without a CoA

Fix: Only source from suppliers that publish batch HPLC + mass-spec data.

Continue researching

Peer-reviewed guides, comparators and matched reference materials.

Primary sources & clinical trials

Peer-reviewed research and registered trials from PubMed, ClinicalTrials.gov, PubChem, FDA and NIH. All links open in a new tab and point to the primary source, so every claim can be verified at origin.

UKP

Written and reviewed by

The UK Peptides Editorial Team · Research library, UK Peptides

The editorial team is responsible for supplier selection, batch release decisions and the content published in this research library. Every article here is sourced to primary literature and every product page to a signed third-party certificate. Corrections are made in place and the review date updated.

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