Human cathelicidin antimicrobial peptide
LL-37
Cited range Host-defense peptide
What it is
LL-37 is the active fragment of human cathelicidin (hCAP18). It kills microbes in vitro and also signals through receptors involved in wound and immune biology.
Benefits in plain language
What researchers and reference users usually mean when they talk about this compound. These are study themes and common claims — not a promise that it will do this in you.
- A human antimicrobial peptide (cathelicidin). It helps kill microbes and also talks to immune and repair cells.
- People look at it for stubborn infection-adjacent research and barrier problems.
- It can also irritate and, in theory, over-rev immune signaling. Not a casual “immune booster.”
- Dosing chatter is all over the map because this is not a vitamin.
If a branded, FDA-approved product exists, that label is the only dose that is actually authorized. Research-chemical vials are a different object.
Mechanism of action
Direct membrane disruption of microbes plus receptor-mediated effects (FPRL1 and others) on chemotaxis and epithelial repair. Immunostimulation cuts both ways.
Possible side effects / caveats
This is not a benign “healing peptide.” Excess LL-37 is discussed in rosacea and inflammatory contexts. Systemic research use deserves more caution than BPC-157 culture implies.
Protocol ranges
| Source tier | Amount | Frequency / duration | Notes |
|---|---|---|---|
| Cited range | 100–500 mcg | Daily or a few times weekly SC in secondary sources | Treat as tentative |