Side-by-side · Research reference

BPC-157vsLL-37

Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.

APhase 2HUMAN-REVIEWED9/53 cited

BHuman-MechanisticHUMAN-REVIEWED15/35 cited

BPC-157

Stable Gastric Pentadecapeptide · Healing

250–500 mcgDaily doseHwang 2016

Phase 2Evidence levelHwang 2016 Sikiric 2018

~30 minHalf-life (est.)

SQ or IM · Local · Once or twice daily

LL-37

Cathelicidin · Human AMP

Broad-spectrumAntimicrobial activity

Membrane disruptionPrimary mechanismLu 2026 He 2026

Innate immunityHost defense rolePinheiro 2026 Zhang 2026

Endogenous · Secreted at inflammation sites

01Mechanism of Action

Parameter

BPC-157

LL-37

Primary target

VEGFR2 / nitric oxide / FAK-paxillin axes (proposed)Chang 2011 Sikiric 2018

Bacterial membranes · Phosphatidylserine-exposed cellsHe 2026 Lu 2026

Pathway

Upregulates VEGFR2 → angiogenesis; modulates NO synthase; promotes fibroblast outgrowth via FAK-paxillinChang 2011

hCAP-18 precursor → Proteinase-3 cleavage → LL-37 release → Membrane insertion/disruption

Downstream effect

Accelerated tissue repair, reduced inflammation, improved gut barrier integritySikiric 2018

Membrane permeabilization, cytokine induction, autophagy, phagosome-lysosome fusion, chemotaxisAhmad 2026 Zhang 2026

Feedback intact?

No known endogenous receptor; mechanism still under investigation

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Origin

Synthetic pentadecapeptide derived from a sequence in human gastric juice; first characterised by Sikiric et al.Sikiric 2018

Endogenous human cathelicidin (37-AA fragment, residues 134–170 of hCAP-18)

Antibody development

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02Dosage Protocols

Parameter

BPC-157

LL-37

Standard dose

250–500 mcg / dayHwang 2016

Anecdotal community range. Phase 2 trial used 1.0 mg PL-14736 IV/day.

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Frequency

Once or twice daily

Split dosing reported anecdotally for chronic injury.

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Lower / starter dose

200 mcg / day

Conservative starter for new users.

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Evidence basis

Animal-strong + Phase 2 clinicalSikiric 2018 Hwang 2016

In vitro, animal models, human observational

Duration

2–4 weeks (acute injury); 4–8 weeks (chronic)

Anecdotal; no long-term human safety data.

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Reconstitution

Bacteriostatic water, 1–2 mL

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Timing

Local SQ to injury site preferred (anecdotal)

Systemic SQ also used; oral bioavailability shown in animal studies.

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Half-life

~30 min plasma (estimated)

Tissue half-life longer; mechanism may explain durable effect.

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Endogenous expression

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Constitutive in neutrophils, epithelial tissues

Upregulated during infection and inflammation.Pinheiro 2026

Exogenous (experimental)

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Dose varies by study; antimalarial ~10–50 μM in vitro

No FDA-approved exogenous formulation.

Plasma levels (malaria)

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Elevated in infected patients and miceHe 2026

Exogenous administration reduced parasitemia in murine models.He 2026

04Side Effects & Safety

Parameter

BPC-157

LL-37

Injection site reaction

Mild irritation (anecdotal)

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GI symptoms

None reported in PL-14736 Phase 2

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Cardiovascular

Not reported

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Cancer risk

Theoretical concern via VEGF angiogenesis pathwaySikiric 2018

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Antibody formation

No data (no long-term human trials)

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Pregnancy / OB

Avoid — insufficient safety data

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Long-term safety

Unknown beyond Phase 2 trial duration

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Drug interactions

None established

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Cytotoxicity (high dose)

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Membrane disruption in host cells at supraphysiological concentrations

Pro-inflammatory signaling

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Can exacerbate inflammation in certain contexts (context-dependent)Pinheiro 2026

Biofilm formation risk

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LL-37-DNA complexes may stabilize dental plaque biofilmsTanabe 2026

Theoretical cancer risk

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Immunomodulatory roles in tumor microenvironment under investigation

Absolute Contraindications

BPC-157

·Pregnancy / breastfeeding
·Known active malignancy (theoretical VEGF concern)

LL-37

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Relative Contraindications

BPC-157

·History of cancer
·Concurrent VEGF inhibitor therapy (theoretical)
·Acute thrombotic events

LL-37

·Active autoimmune disease (theoretical immune dysregulation)

05Administration Protocol

Parameter

BPC-157

LL-37

1. Reconstitution

Add 1–2 mL bacteriostatic water to a 5 mg vial. Roll gently; do not shake. Solution should be clear and colourless.

LL-37 is constitutively expressed in neutrophils and epithelial cells, cleaved from hCAP-18 by proteinase-3 at sites of infection or inflammation.

2. Injection site

Subcutaneous near the injury site is the most common anecdotal route. Systemic SQ (abdomen) also used. Rotate sites.

Synthetic LL-37 and derivatives (e.g., SAMP-12aa) tested in vitro and animal models. Administered via topical, intraperitoneal, or intravenous routes in research settings.

3. Timing

No strict timing requirement. Most users dose once or twice daily, often morning + evening.

LL-37 is resistant to pepsin degradation at gastric pH. Synthetic short peptides designed to retain this stability while reducing toxicity.Lu 2026

4. Storage

Lyophilised: room temp, light-protected. Reconstituted: refrigerate 2–8 °C, use within 30 days.

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5. Needle

27–31G insulin syringe, 4–8 mm. Local injection allows finer 31G.

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06Stack Synergy

BPC-157

+ TB-500

Strong

View TB-500 →

BPC-157 and TB-500 (Thymosin β-4) target distinct healing axes: BPC-157 upregulates VEGF-driven angiogenesis and fibroblast migration; TB-500 increases actin remodelling and cell migration via the actin-sequestering β-thymosin domain. Stacked, they cover both vascular (BPC) and structural (TB-500) regeneration pathways. Anecdotally favoured for tendon and ligament repair where both pathways contribute.

BPC-157: 250–500 mcg SQ · daily
TB-500: 2 mg SQ · 2× per week
Primary benefit: Tendon/ligament/muscle repair via complementary angiogenesis + migration

LL-37

— no documented stacks