Peptide LibraryLL-37 dosage in published studies and labels
These are the doses used for LL-37 in FDA labelling and published clinical studies, reported as each source states them, one row per regimen. They describe what was studied or approved for a specific population. They are not a recommendation, and none of them is a dose for any individual.
Research and educational reference only. This is not medical advice, and no figure on this page is a dosing recommendation.
Last checked against primary sources:
Studied regimens and sources
LL-37 has published human dosing, but only for topical and intralesional use, and the dosing is expressed as a concentration applied to a wound rather than as a systemic dose. The largest study, the phase IIb HEAL LL-37 trial, applied 0.5 or 1.6 mg/mL topically to hard-to-heal venous leg ulcers in 148 patients; both strengths were safe and well tolerated, and neither improved healing over placebo on the primary analysis. No human study has given LL-37 by subcutaneous injection, which is how it is generally sold.
| Human dosing established | Yes |
|---|---|
| Route | Topical (both controlled wound-healing trials) · Intratumoral (phase 1 melanoma programme) · Oral, as a recombinant Lactococcus lactis product rather than the free peptide |
| Frequency | Varies by study: daily to twice-weekly topical application, or weekly intratumoral injection |
| Duration studied | 4 weeks in the diabetic foot ulcer trial; longer in the venous leg ulcer programme |
| Evidence level | Limited Human Evidence |
| Last reviewed | 2026-09-05 |
Research-reported dosing
Doses as studied, one row per regimen. Different trials used different regimens; they are listed separately rather than averaged.
| Study / context | Population | Dose | Route | Frequency | Duration | Outcome studied | Source |
|---|---|---|---|---|---|---|---|
| HEAL LL-37 — phase IIb, completed, publishedClinical trial · Phase IIb double-blind randomised placebo-controlled trial, published with results | 148 patients with hard-to-heal venous leg ulcers, mean age 67.6 years | 0.5 mg/mL or 1.6 mg/mL, applied topically to the wound alongside compression therapy | Topical | Per the trial protocol, in combination with compression therapy | Full trial course; median ulcer duration at entry was 20.3 months | Wound healing. The primary analysis found no significant improvement over placebo; a post-hoc subgroup with wounds of at least 10 cm2 did show improvement. Both strengths were safe and well tolerated. | Evaluation of LL-37 in healing of hard-to-heal venous leg ulcers: A multicentric prospective randomized placebo-controlled clinical trial. Wound Repair Regen. 2021. |
| Diabetic foot ulcer cream — randomised double-blind trial, publishedClinical trial · Randomised double-blind controlled trial, registered as NCT04098562 | Adults with diabetic foot ulcer with mild infection | LL-37 cream; the report does not state the concentration of the cream | Topical | Twice a week | 4 weeks, with wounds measured on days 7, 14, 21 and 28 | Granulation index improved consistently versus placebo. IL-1 alpha, TNF-alpha and aerobic bacterial colonisation were not significantly reduced. | Efficacy of LL-37 cream in enhancing healing of diabetic foot ulcer: a randomized double-blind controlled trial. Arch Dermatol Res. 2023. |
| NCT04098562 — phase 2, registry entry for the diabetic foot ulcer creamClinical trial · Registered phase 2 trial; registry status listed as unknown | Planned 40 participants with diabetic foot ulcer | LL-37 cream; the registry record does not disclose the concentration | Topical | — | — | Bacterial colonisation, inflammation response and wound healing | NCT04098562 — Efficacy of LL-37 Cream on Bacteria Colonization, Inflammation Response and Wound Healing in Diabetic Foot Ulcer |
| Intratumoral LL-37 in melanoma — phase 1 programme, toxicity case reportClinical trial · Case report of dermatologic toxicity arising within a phase 1 clinical trial | Patient with stage IIIC cutaneous melanoma, within a phase 1 trial of intratumoral LL-37 | Weekly intratumoral injection; the amount per injection is not stated in this report | Intratumoral | Once weekly | 8 injections | Injected lesions shrank. Widespread verrucous and keratoacanthoma-like skin lesions developed around day 45 and resolved within 2 months of stopping treatment. | Dermatologic toxicity from novel therapy using antimicrobial peptide LL-37 in melanoma: A detailed examination of the clinicopathologic features. J Cutan Pathol. 2018. |
Preclinical and analog research
Not human dosing evidence. Listed for completeness and never extrapolated to a human dose.
| Study / context | Population | Dose | Route | Frequency | Duration | Outcome studied | Source |
|---|---|---|---|---|---|---|---|
| Oral LL-37 for COVID-19 — delivered by a live bacterial vector, not as the peptideClinical trial · Open-label randomised placebo-controlled single-centre trial of a live bacterial vector expressing LL-37, not of the peptide itselfStudied an analog, not LL-37 itself | 238 adult inpatients with Omicron BA.5.1.3 infection | Recombinant LL-37 Lactococcus lactis given by mouth; the peptide amount delivered is not quantified in the report | Oral | — | From confirmation of infection through hospitalisation | Shorter time to SARS-CoV-2 RNA negative conversion (9.80 vs 14.04 days) when started within 6 days. No severe adverse events reported. | Efficacy and safety of Oral LL-37 against the Omicron BA.5.1.3 variant of SARS-COV-2: A randomized trial. J Med Virol. 2023. |
Preclinical research: LL-37 is the only human cathelicidin and has a large basic literature, most of it concerned with its endogenous role rather than with administering it. A recurring theme in that work is that LL-37 is not straightforwardly beneficial: excess endogenous LL-37 is implicated in the pathology of rosacea and psoriasis, and it has been reported to promote proliferation and invasion in some tumour models. Several of the trials that appear in a search for LL-37 do not administer it at all — they give vitamin D or another agent and measure endogenous LL-37 as a downstream marker.
Where sources disagree
- LL-37 is sold as a lyophilised vial for subcutaneous injection, commonly with protocols in the hundreds of micrograms daily. No human study has given LL-37 subcutaneously. Every published human dose is topical, intralesional or delivered by an engineered bacterium, and a wound concentration in mg/mL does not convert into an injected microgram dose.
- The largest and best-controlled human study, the phase IIb HEAL LL-37 trial in 148 patients, did not meet its primary endpoint: LL-37 was no better than placebo for healing across the whole cohort. The positive finding was a post-hoc subgroup analysis in patients with wounds of at least 10 cm2, which the authors themselves describe as warranting a further adequately powered study.
- The oral COVID-19 trial is frequently cited as evidence for oral LL-37. The product studied was Lactococcus lactis engineered to express LL-37, not the peptide, and the amount of peptide delivered was not quantified — so it supports nothing about swallowing or dissolving LL-37 itself.
- The compound in the venous leg ulcer programme is being developed under the non-proprietary name ropocamptide. Material sold as research LL-37 is not that product and has not been through its manufacturing or characterisation.