Semax vs LL-37
Side-by-side comparison of key properties, dosing, and research.
- Summary
- Semax is a synthetic heptapeptide derived from ACTH developed in Russia. It is a potent nootropic that enhances memory, focus, and provides neuroprotection. Approved in Russia for cognitive disorders, stroke recovery, and traumatic brain injury.
- 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
- Minutes (but effects persist for hours via BDNF induction)
- Very short (~1–2 hours) in plasma due to protease degradation; topical use bypasses systemic clearance
- Admin Route
- Intranasal, SubQ
- SubQ, Topical, Intranasal
- Research
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- Typical Dose
- 0.25–1 mg (250–1000 mcg)
- 100–300 mcg
- Frequency
- 1–2 times daily
- 2–3x per week
- Key Benefits
- Enhances memory and learning
- Improves focus and concentration
- Increases mental energy and motivation
- Provides neuroprotection via BDNF and NGF upregulation
- Reduces cognitive decline
- May alleviate ADHD symptoms
- Supports recovery from brain injury and stroke
- Fast-acting — effects within 30–60 minutes
- Approved in Russia for cognitive disorders and stroke recovery
- 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
- Headache (rare, often from higher doses)
- Anxiety or overstimulation at high doses
- Sleep disruption if dosed too late
- Irritability (uncommon)
- 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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