BPC-157 vs LL-37
A neutral, side-by-side comparison of two healing & recovery peptides — their mechanisms, dosing ranges, administration routes, side effects, and research evidence. For research and educational purposes only.
BPC-157
BPC-157 is a synthetic 15-amino-acid peptide derived from a protective protein found in human gastric juice. It has been extensively studied in animal models for tissue repair, gastroprotection, and tendon/ligament/muscle healing. Important: essentially all efficacy data are preclinical (rodent), there are no completed published human efficacy trials, and it is prohibited in sport by WADA.
Full profileLL-37
LL-37 is the only human cathelicidin — a host defense peptide produced by neutrophils, epithelial cells, and macrophages in response to infection and inflammation. It functions simultaneously as a broad-spectrum antimicrobial agent and an immune-modulatory signaling molecule. Research interest has expanded dramatically since COVID-19 studies linked low LL-37 levels to severe outcomes, and gut health research identified it as a key regulator of intestinal barrier integrity.
Full profile| BPC-157 | LL-37 | |
|---|---|---|
| Category | Healing & Recovery | Healing & Recovery |
| Also known as | Body Protection Compound 157, PL 14736, Pentadecapeptide BPC 157 | Cathelicidin LL-37, hCAP-18 C-terminal fragment, CRAMP (murine equivalent) |
| Evidence | Preclinical only | Research-stage |
| Dosing range | 200mcg–1000mcg mcg, once or twice daily | 100mcg–500mcg mcg, Daily or 3–5x weekly |
| Administration | Subcutaneous injection (most common), Intramuscular injection, Oral (reduced bioavailability — used for gut-specific protocols) | Subcutaneous injection, Intranasal (for respiratory applications), Topical (wound care) |
| Key side effects | Nausea (rare, typically at higher doses), Dizziness / lightheadedness shortly after injection (uncommon, anecdotal), Injection site redness or irritation, Human safety profile is not established — no controlled human trials | Injection site redness and irritation (common — pro-inflammatory at injection site), Transient flu-like symptoms (immune activation), Local induration, High doses may be cytotoxic — dose-response curve is non-linear |
| Cited sources | 6 references | 3 references |
Key differences
- Evidence level differs: BPC-157 is preclinical only, while LL-37 is research-stage.
- Administration: BPC-157 — Subcutaneous injection (most common), Intramuscular injection, Oral (reduced bioavailability — used for gut-specific protocols); LL-37 — Subcutaneous injection, Intranasal (for respiratory applications), Topical (wound care).
- Frequency: BPC-157 is typically once or twice daily; LL-37 is Daily or 3–5x weekly.
- Research depth: this profile cites 6 sources for BPC-157 vs 3 for LL-37.
How each works
BPC-157
Preclinical rodent and in-vitro studies — predominantly from the Sikiric group in Zagreb, with mechanistic angiogenesis work from Pang's group in Taiwan — report accelerated healing of tendon, ligament, muscle, and gut tissue. Proposed mechanisms include modulation of the nitric oxide (NO) system, promotion of angiogenesis via the VEGFR2–Akt–eNOS pathway, upregulation of growth factor signaling, and effects along the gut–brain axis. Despite a large and internally consistent animal literature, BPC-157 has no completed human clinical efficacy trials and is an unapproved drug.
LL-37
LL-37 exerts antimicrobial activity by disrupting bacterial membranes via electrostatic interaction with negatively charged lipopolysaccharide — effective against gram-positive and gram-negative bacteria, fungi, and enveloped viruses including SARS-CoV-2 in vitro. Beyond direct antimicrobial action, LL-37 modulates innate immunity through TLR4 signaling, promotes wound healing via EGFR and FPRL1 receptor activation, and has demonstrated anti-biofilm activity against P. aeruginosa and S. aureus. Vitamin D is the primary driver of endogenous LL-37 production.
This comparison aggregates public research and structured profile data for informational purposes only. It is not medical advice and does not recommend either compound for human use. Consult a qualified healthcare provider before considering any peptide.