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LL-37

Infections, wound healing

Your body's own antimicrobial weapon. Fights bacteria, breaks up biofilms, helps wounds heal.

In Plain English

Your immune system's first line of defense — kills harmful bacteria and helps repair the damage they cause.

C

At a glance

Your own antimicrobial peptide. Injection sites hurt. Evidence grade C on an A-to-D scale.

HOW IT IS TAKEN
Under the skin
HOW OFTEN
Daily
HOW LONG
Short courses
TESTED SPORT
Not banned

Reported practice from trials and the community, not a recommendation for anyone.

What Researchers Have Studied It For

+Fighting bacterial infections
+Breaking up biofilms
+Wound healing
+Immune defense
+Skin healing
Molecular Weight
4493 Da
Half-Life
~30 minutes
Source
37 amino acid antimicrobial peptide
Storage
Keep frozen as powder. Refrigerate once mixed.
Category
Recovery

Published Research

LL-37 the only human cathelicidin
Biochim Biophys Acta (2006)

Common questions about LL-37

What is LL-37 used for?

Researchers have studied LL-37 for fighting bacterial infections, breaking up biofilms, wound healing, and more. In plain terms: Your immune system's first line of defense — kills harmful bacteria and helps repair the damage they cause.

Is LL-37 FDA-approved?

No. LL-37 is not approved for human use anywhere. It is sold as a research chemical, which means no manufacturing standard, no batch recall and no one to report a problem to. The only quality control is the buyer's own.

How is LL-37 usually taken?

The commonly reported pattern is under the skin, daily, for short courses. That describes reported practice from trials and the community. It is not a recommendation for anyone, and several of these compounds interact with common medications.

How strong is the evidence for LL-37?

Grade C on this site's A-to-D scale. C means tested only in animals or cells, so everything about human use is an educated guess. Your own antimicrobial peptide. Injection sites hurt.

Is LL-37 banned in drug-tested sport?

It is not specifically listed by the World Anti-Doping Agency, but tested athletes should check the current list and their federation's rules, since related compounds and blends often are.

How long does LL-37 stay in the body?

The half-life, the time for half a dose to leave the body, is about ~30 minutes. A short half-life means it wears off fast and is taken more often; a long one means once a week can be enough. Stored as a dry powder it keeps for months in the fridge; once mixed with water it is used within a few weeks.

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Go deeper on LL-37 in The Peptide Course
How people commonly use it, what they notice, side effects, who stays away, and how good the evidence really is. Plus how to buy a vial that is actually LL-37, and how to mix it. Six lessons are free.
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Research-use disclaimer — LL-37 is referenced here for research education only. It is not approved by the FDA for human consumption, treatment, cure, or diagnosis of any condition. Nothing on this page is medical advice. Consult a licensed physician for anything related to your health.