Side-by-side · Research reference
LL-37vsTestagen
Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.
AHuman-MechanisticHUMAN-REVIEWED15/35 cited
BAnimal-MechanisticHUMAN-REVIEWED11/41 cited
LL-37
Cathelicidin · Human AMP
Broad-spectrumAntimicrobial activity
Endogenous · Secreted at inflammation sites
Testagen
Bioregulator Peptide · Khavinson School
SQ · Abdomen · Cyclical
01Mechanism of Action
Parameter
LL-37
Testagen
Primary target
Testicular tissue; proposed nuclear DNA interaction
Pathway
hCAP-18 precursor → Proteinase-3 cleavage → LL-37 release → Membrane insertion/disruption
Nuclear penetration → DNA/oligonucleotide binding → gene expression modulation (bioregulator hypothesis)Fedoreyeva 2011
Downstream effect
Membrane permeabilization, cytokine induction, autophagy, phagosome-lysosome fusion, chemotaxisAhmad 2026Zhang 2026
Proposed support for spermatogenesis and testicular function; mechanistic data limited to nuclear localization and DNA interactionFedoreyeva 2011
Feedback intact?
—
Unknown — no HPG axis data
Origin
Endogenous human cathelicidin (37-AA fragment, residues 134–170 of hCAP-18)
Khavinson bioregulator school — isolated from testicular tissue peptide fractions
Antibody development
—
—
02Dosage Protocols
Parameter
LL-37
Testagen
Endogenous expression
Constitutive in neutrophils, epithelial tissues
Upregulated during infection and inflammation.Pinheiro 2026
—
Exogenous (experimental)
Dose varies by study; antimalarial ~10–50 μM in vitro
No FDA-approved exogenous formulation.
—
Plasma levels (malaria)
Elevated in infected patients and miceHe 2026
Exogenous administration reduced parasitemia in murine models.He 2026
—
Evidence basis
In vitro, animal models, human observational
Animal mechanistic / in vitro onlyFedoreyeva 2011
Typical protocol (anecdotal)
—
100–200 mcg / day
No published human dosing studies; derived from Russian bioregulator practice.
Frequency
—
Once daily or alternate days
Cycle length
—
10–20 days on, 10–14 days off
Bioregulator tradition uses pulsed cycles; no controlled data.
Route
—
Subcutaneous
Reconstitution
—
Sterile water or bacteriostatic saline
Half-life
—
Unknown — likely minutes (short peptide)
04Side Effects & Safety
Parameter
LL-37
Testagen
Cytotoxicity (high dose)
Membrane disruption in host cells at supraphysiological concentrations
—
Pro-inflammatory signaling
Can exacerbate inflammation in certain contexts (context-dependent)Pinheiro 2026
—
Theoretical cancer risk
Immunomodulatory roles in tumor microenvironment under investigation
—
Injection site reactions
—
Erythema, mild irritation (potential)
Systemic effects
—
Unknown — no human safety data
Hormonal impact
—
No published data on testosterone, LH, FSH effects
Long-term safety
—
Unknown — no long-term studies
Absolute Contraindications
LL-37
—Testagen
- ·Active testicular malignancy
Relative Contraindications
LL-37
- ·Active autoimmune disease (theoretical immune dysregulation)
Testagen
- ·Hormone-sensitive cancers (no data; theoretical caution)
- ·Pregnant or breastfeeding (no data)
05Administration Protocol
Parameter
LL-37
Testagen
1. Natural secretion
LL-37 is constitutively expressed in neutrophils and epithelial cells, cleaved from hCAP-18 by proteinase-3 at sites of infection or inflammation.
Add 1–2 mL sterile or bacteriostatic water to lyophilised vial. Swirl gently; do not shake. Solution should be clear.
2. Experimental formulations
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.
Subcutaneous — abdomen or thigh. Rotate sites daily. Use standard insulin syringe (27–31G).
3. Stability considerations
LL-37 is resistant to pepsin degradation at gastric pH. Synthetic short peptides designed to retain this stability while reducing toxicity.Lu 2026
Morning or evening; no established optimal timing. Anecdotal preference: evening to align with circadian testosterone patterns.
4. Storage
—
Lyophilised: room temp, dark. Reconstituted: refrigerate 2–8 °C, use within 14–21 days if bacteriostatic water used.
5. Cycle protocol
—
10–20 days on, 10–14 days off. Bioregulator tradition uses pulsed exposure; rationale: prevent receptor/pathway desensitisation.