LL-37: where it stands with the FDA, and what it costs
No FDA-approved drug contains it.
Go to clinicLowest per monthLL-37 injection (10mg)
FormBlends · $179.10/mo
Where LL-37 stands today
No FDA-approved drug contains LL-37. FDA had it in 503A Category 2 from September 2023 until April 22, 2026 (nomination withdrawn), citing nonclinical findings of detrimental effects on male reproduction and possible tumor promotion. FDA plans an advisory committee review before the end of February 2027. It is not on the 503A or 503B bulks list, is in no category, and is not in HHS's October 2026 interim policy.
For pharmacies compounding one patient's prescription (section 503A)
Not in any 503A category and not on the 503A bulks list. Removed from Category 2 on April 22, 2026 (nomination withdrawn); advisory committee review planned before the end of February 2027. Not in HHS's Oct 2026 interim policy.
“Bulk drug substances nominated but withdrawn ... Cathelicidin LL-37 Compounded drugs containing cathelicidin LL-37 may pose risk for immunogenicity for certain routes of administration and may have complexities with regard to peptide-related impurities and API characterization. FDA lacks sufficient safety-related information regarding cathelicidin LL-37 to know whether the drug would cause harm when administered to humans. Nonclinical research findings suggest detrimental effects on male reproduction and that this drug can be protumorigenic in some tissues.”
““Cathelicidin LL-37” has been removed from category 2 because the nomination was withdrawn by the nominator.”
FDA interim 503A bulks policy: a substance outside Category 1 gets no interim enforcement discretion
“Drug products compounded using a bulk drug substance for which each of the above circumstances are not present are not within the scope of the policy described in this guidance.”
For outsourcing facilities (section 503B)
Not on the 503B bulks list and not in any 503B category (FDA's 503B nominations list, updated March 21, 2025, does not name it)
“Outsourcing facilities, which operate under section 503B of the Federal Food, Drug, and Cosmetic Act (FD&C Act), may not compound a drug product that includes a bulk drug substance unless: The bulk drug substance appears on a list identifying bulk drug substances for which there is a clinical need (the 503B bulks list), or”
The 503B bulks list holds five substances (diphenylcyclopropenone, glycolic acid, quinacrine HCl oral, squaric acid dibutyl ester, trichloroacetic acid); none of the compounds in this file
“FDA has evaluated the following bulk drug substances and determined that there is a clinical need for outsourcing facilities to compound drug products using these bulk drug substances under section 503B of the FD&C Act:”
The FDA's compounding advisory committee
Invalid Date: Whether to include cathelicidin (LL-37) on the 503A bulks list. Pending
“FDA will host an advisory committee meeting before the end of February 2027 ... The Committee will discuss the following bulk drug substances being considered for inclusion on the 503A bulks list: Cathelicidin (LL-37)”
Our reading
There is no current route to lawful 503A or 503B compounding of LL-37; that could change only after the planned committee meeting and an FDA or HHS decision.
Every source above was checked again on 14 November 2026.
What 4 clinics charge
- FormBlendsLL-37 injection (10mg)$179.10/mo
- Peps RXLL-37 injection (2mg/ml)$259/mo
What LL-37 is
- What it is
- Antimicrobial peptide (human cathelicidin)
- How it works
- The one human cathelicidin, a peptide of the innate immune system.
- How it is given
- Subcutaneous injection
- Also called
- cathelicidin
About LL-37
Is LL-37 FDA-approved?
No. No FDA-approved drug contains LL-37. What clinics sell is compounded by a pharmacy for a prescription, and the FDA does not review compounded products before they are sold.
Is LL-37 legal in the US?
Whether a pharmacy may compound it for your prescription is what decides it. No FDA-approved drug contains LL-37. FDA had it in 503A Category 2 from September 2023 until April 22, 2026 (nomination withdrawn), citing nonclinical findings of detrimental effects on male reproduction and possible tumor promotion. FDA plans an advisory committee review before the end of February 2027. It is not on the 503A or 503B bulks list, is in no category, and is not in HHS's October 2026 interim policy.
How much does LL-37 cost?
4 clinics publish a price. The lowest that compares per month is $179.10/mo at FormBlends. What a month buys differs by clinic, so each price lists what it includes. every LL-37 price