Evidence brief
LL-37
Written and source-checked by Anthony Treviso, founder of The Peptide Field.
Direct answer
LL-37 is a peptide made of 37 amino acids. The body releases it from a larger starting protein. Human studies tested different products for wounds, melanoma, and COVID-19. Melanoma is a type of skin cancer. These studies do not prove a general health benefit. No FDA-approved U.S. LL-37 drug was found in the records checked.
LL-37 is a body-made peptide with 37 amino acids. Human studies do not prove a general health benefit. No FDA-approved LL-37 drug was found.
- How strong is the evidence?
- Insufficient
Reliable studies in people are missing, too limited, or do not support the claim. This does not prove that the substance has no effect on the body. - What evidence exists?
- Investigational human outcomes
Studies measured health results in people, but the molecule is still being studied and is not approved for that use. Important questions remain. - Sports rules
- Not assessed
No current sports-rule review is available.
Reviewed August 30, 2026. Sources and update notes are below.
No sales or dosing advice. This guide explains research. It was not independently medically reviewed, and it does not diagnose, prescribe, or recommend treatment.
Also known as LL37 · Cathelicidin LL-37 · Ropocamptide
Words used here
- peptide
- a short chain of amino acids
- amino acid
- a small building block that makes peptides and proteins
- investigational
- still being studied and not approved for that use
- outcome
- what the study measured
- molecule
- one specific chemical substance
- placebo
- an inactive treatment used for comparison
- mechanism
- how a substance may cause a body change
- biomarker
- a body or lab measurement, not automatically a health benefit
More detailProduct and study details
01 · Evidence profile
Four questions about the evidence
Wound studies found mixed results. In a later study, 148 people received LL-37 or placebo. It found no clear healing benefit in the full group.
The studies do not show how each LL-37 form moves through or affects the body. Researchers used different products in different ways.
FDA says there is not enough safety information. It notes possible immune reactions, impurities, and uncertainty about product contents. Animal and cell findings do not prove harm in people.
FDA keeps LL-37 amide in a separate chemical record. An online product name does not prove its contents or quality.
02 · Identity
What it is
LL-37 is a defense peptide made by the body. It helps protect against germs. It has 37 amino acids. The body makes it by cutting a larger protein called hCAP18. Ropocamptide is another name used in FDA records. LL-37 amide is a different chemical form with its own FDA record.
Scientific group: Body-made host-defense peptide. This group name describes the type of molecule or body signal. It does not prove a benefit, safety, or approval.
03 · Exact product
The molecule is not the finished product.
Formulation: The finished product's ingredients and physical form. Route: How the product enters the body. Indication: The approved or studied use and group of people for a product.
None identified in the United States.
- Human research in venous leg ulcers
- Human research in diabetic foot ulcers
- Early research in melanoma and COVID-19
04 · Research results
What the research shows
An early 34-person study of hard-to-heal leg ulcers caused by vein problems reported signs of better healing. A later double-blind study assigned 149 people to topical LL-37 or placebo. Both groups also received compression care. Of those people, 148 received a study treatment. The study found no clear healing benefit in the full group. A later analysis suggested more benefit in people with larger wounds. That was not the study's main test and needs confirmation.
A 25-person study of diabetic foot ulcers used a topical cream for four weeks. It found a higher score for new tissue growth. It found no clear difference in signs of inflammation or the amount of bacteria. A melanoma study enrolled four people in one group. Melanoma is a type of skin cancer. The study cannot prove a cancer benefit.
A 238-person COVID-19 study used a modified bacterium that made a lab-produced form of LL-37. The full group did not clear the virus faster on testing. A group of 48 people started treatment within six days of a positive test.
That group included 20 people assigned to LL-37 and 28 assigned to placebo. The early group had a signal. Patients and researchers knew which treatment was given. The study took place at one medical center and covered the Omicron BA.5.1.3 variant.
These studies do not prove that LL-37 heals wounds in general, prevents or treats cancer or COVID-19, or improves health for people in general. The wound results differed by study and subgroup. The COVID-19 study did not test a standard LL-37 vial, spray, or plain peptide product.
FDA says there is not enough safety information. It notes possible immune reactions, impurities, and uncertainty about product contents. FDA also cites animal and cell findings about male reproduction and possible tumor growth. These findings do not prove harm in people.
The person or group that asked FDA to consider LL-37 for its pharmacy-compounding list withdrew the request. This is not a ban or a place on the list. FDA plans a discussion with an advisory committee before the end of February 2027. The committee will give advice. It will not make a final FDA decision.
Exact product
LL-37 is also called ropocamptide. LL-37 amide is a separate FDA substance record, not an exact alias. FDA records and human studies do not show that an online product has the same form, contents, quality, or study material.
05 · Claim check
Claims I checked
6 claims checked for this brief.
“LL-37 is a 37-amino-acid human peptide.”
FDA's detailed chemical record lists ropocamptide as a peptide with 37 amino acids. This record does not show product quality or human benefit.
- Evidence used
- Regulatory or product record. This answer uses an official regulator record or a specific product label.
- Limits of this answer
- FDA identity records for LL-37 and ropocamptide; this does not establish the identity or quality of an online product. This answer covers only the named molecule and finished product. It also covers the product form and how people used it. The study limits include who took part, what was used for comparison, what changed, and how long the study lasted.
“LL-37 is proven to heal wounds in people.”
The first 34-person leg-ulcer study reported possible benefit. A later study assigned 149 people to LL-37 or placebo. Of those people, 148 received a study treatment. It found no clear benefit for the full group. A 25-person diabetic-foot-ulcer study found a limited sign of new tissue growth, but no clear changes in other measures. These results do not prove general wound healing.
- Evidence used
- Randomized human outcomes. This answer uses a study that assigned people to groups by chance and measured a health outcome.
- Limits of this answer
- The reviewed venous-ulcer studies and small diabetic-foot-ulcer study; results apply only to their defined products, groups, wound types, and follow-up periods. This answer covers only the named molecule and finished product. It also covers the product form and how people used it. The study limits include who took part, what was used for comparison, what changed, and how long the study lasted.
“The LL-37 COVID-19 study tested a standard LL-37 peptide product.”
The 238-person study used an engineered bacterium that made a lab-produced form of LL-37. Patients and researchers knew which treatment was given. The study took place at one medical center. It did not test a standard LL-37 vial, spray, or plain peptide product.
- Evidence used
- Randomized human outcomes. This answer uses a study that assigned people to groups by chance and measured a health outcome.
- Limits of this answer
- The engineered bacterium used in the study and the one-center setting; this does not establish results for other LL-37 materials. This answer covers only the named molecule and finished product. It also covers the product form and how people used it. The study limits include who took part, what was used for comparison, what changed, and how long the study lasted.
Show 3 more claim checks
“LL-37 is FDA-approved in the United States.”
No FDA-approved U.S. LL-37 drug was found when Drugs@FDA was checked for LL-37 and ropocamptide on August 30, 2026. An FDA chemical record identifies a substance. It does not mean that FDA approved a drug.
- Evidence used
- Regulatory or product record. This answer uses an official regulator record or a specific product label.
- Limits of this answer
- United States approval status as reviewed August 30, 2026. This answer covers only the named molecule and finished product. It also covers the product form and how people used it. The study limits include who took part, what was used for comparison, what changed, and how long the study lasted.
“FDA has banned LL-37.”
The person or group who asked FDA to consider LL-37 for its pharmacy-compounding list withdrew the request. That request was called a 503A nomination. Its withdrawal is not a ban. The current federal rule does not list LL-37. FDA plans an advisory-committee discussion before the end of February 2027. That discussion is not a final decision or drug approval.
- Evidence used
- Regulatory or product record. This answer uses an official regulator record or a specific product label.
- Limits of this answer
- The U.S. pharmacy-compounding status as reviewed August 30, 2026; an advisory discussion is not a final FDA action. This answer covers only the named molecule and finished product. It also covers the product form and how people used it. The study limits include who took part, what was used for comparison, what changed, and how long the study lasted.
“LL-37, LL-37 amide, and products sold online as LL-37 are interchangeable.”
FDA has separate records for ropocamptide (LL-37) and LL-37 amide. An online product name does not prove the same chemical form, amino-acid order, purity, or quality.
- Evidence used
- Regulatory or product record. This answer uses an official regulator record or a specific product label.
- Limits of this answer
- FDA identity records and online product names; this is not advice on how to use a product. This answer covers only the named molecule and finished product. It also covers the product form and how people used it. The study limits include who took part, what was used for comparison, what changed, and how long the study lasted.
06 · Questions
Questions people ask about LL-37
No final FDA ban was identified. The person or group who asked FDA to consider LL-37 for its pharmacy-compounding list withdrew the request. FDA plans to ask an advisory committee about LL-37 before the end of February 2027. That future advice will not approve a drug or make a final decision about the list.
No FDA-approved U.S. LL-37 drug found; FDA plans an advisory-committee discussion before the end of February 2027. No approved product is identified in the United States.
Not assessed. This editorial review did not determine sport eligibility. Athletes must check the current prohibited list, Global DRO, and their governing body. This status is not personal clearance to compete.
Human wound studies had mixed results. A later 149-person study found no clear healing benefit for the full group. Small foot-ulcer and melanoma studies do not prove a general benefit. A COVID-19 study tested an engineered bacterium that made LL-37, not a standard peptide product. The full group did not clear the virus faster on testing.
The reviewed evidence does not show whether LL-37 helps wounds or treats cancer or COVID-19 for people in general. The safety and contents of products sold online are also unknown. FDA says there is not enough safety information.
07 · Safety
Safety limits for this record
FDA's review does not show that every LL-37 form or product is safe. It includes animal and cell concerns that do not prove risk in people. This guide does not tell readers how much to use, how to take it, where to buy it, which product to choose, or how to treat a condition.
This editorial review did not determine sport eligibility. Athletes must check the current prohibited list, Global DRO, and their governing body.
No current sports-rule review is available.
Reviewed .Check current rules for tested sport ↗08 · Sources
Read the sources
09 · Review history
Review history
Initial review covered FDA records and human studies of leg ulcers, melanoma, and COVID-19. It also covered FDA's planned advisory-committee discussion.
Written and source-checked by Anthony Treviso, founder of The Peptide Field.
Not independently medically reviewed. This page is not a dosing, sourcing, or treatment guide.