Testagen vs LL-37
Side-by-side comparison of key properties, dosing, and research.
- Summary
- Testagen is a tetrapeptide bioregulator (Lys-Glu-Asp-Gly) developed by Professor Vladimir Khavinson, tissue-specific for the testes. It supports Leydig cell function, normalization of testosterone biosynthesis, and spermatogenic activity. Testagen is used in men's health protocols for age-related testosterone decline, male fertility support, and testicular anti-aging.
- LL-37 is the only known human cathelicidin antimicrobial peptide. It kills bacteria, fungi, and viruses by disrupting their membranes, while simultaneously modulating immune responses. Used for antimicrobial protection, immune priming, and wound healing.
- Half-Life
- Short (minutes); sustained gene-regulatory effects
- Very short (~1–2 hours) in plasma due to protease degradation; topical use bypasses systemic clearance
- Admin Route
- SubQ, Oral
- SubQ, Topical, Intranasal
- Research
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- Typical Dose
- 10 mg per day
- 100–300 mcg
- Frequency
- Daily for 10–30 days
- 2–3x per week
- Key Benefits
- Supports endogenous testosterone synthesis via Leydig cell normalization
- Promotes spermatogenesis and sperm quality
- Anti-aging effects on testicular tissue
- May attenuate age-related testosterone decline
- Mechanistically distinct from TRT — does not suppress HPG axis
- Useful adjunct to Gonadorelin and Kisspeptin-10 in male hormonal protocols
- Supports male fertility without exogenous hormone replacement
- Broad-spectrum antimicrobial (bacteria, fungi, viruses)
- Promotes wound healing and angiogenesis
- Immune system modulation — enhances innate immunity
- Reduces LPS-mediated endotoxemia
- Anti-biofilm activity against resistant organisms
- Promotes tissue regeneration and keratinocyte migration
- May protect against sepsis
- Side Effects
- Generally well tolerated
- Mild injection site reactions
- No significant endocrine disruption reported at standard doses
- Injection site redness and irritation
- Mild inflammatory response at injection site
- Potential pro-inflammatory at high doses
- Rare: fever or flu-like symptoms at initiation
- Stacks With
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