LL-37 Dosage Chart: What Trials Used vs What Reddit Reports

This LL-37 dosage chart keeps two things apart that most dosing pages blend together: the concentrations that human trials actually applied, and the daily amounts people on Reddit say they inject. The trial numbers are all topical, oral or in a dish. The Reddit numbers are a handful of anecdotes. No published study has dosed LL-37 by subcutaneous injection, so neither set is a prescription.

For what LL-37 is and how the evidence stacks up overall, see our LL-37 peptide guide. This page is the dose-focused companion.

LL-37 dosage chart: what the published studies used

Start with the table below, because it answers the question most people arrive with: what number appears in a paper. The honest answer is that the numbers are concentrations on a wound, not milligrams in a syringe.

The first human trial enrolled 34 people with hard-to-heal venous leg ulcers and applied LL-37 at 0.5, 1.6 or 3.2 mg/mL twice a week for four weeks after a three-week placebo run-in (PMID 25041740). Healing rate constants for the 0.5 and 1.6 mg/mL groups were roughly six and three times placebo (p = 0.003 and 0.088, so the second did not reach significance), mean ulcer area fell 68 percent and 50 percent, and the 3.2 mg/mL group did not differ from placebo. The authors reported no safety concerns. This is the strongest dose-response result in the whole literature, and it points the opposite way from the "more is better" instinct.

The follow-up is less encouraging. The HEAL LL-37 phase IIb trial randomized 148 patients to 0.5 mg/mL, 1.6 mg/mL or placebo on top of compression therapy (PMID 34687253). The full population showed no significant improvement over placebo. A post hoc look at ulcers of 10 cm2 or more did show benefit, which the authors treated as a lead for a future trial, not a result. The treatment was well tolerated at both strengths.

Two more human trials exist, and neither is a vial in a fridge. A 2023 randomized trial of an LL-37 cream on diabetic foot ulcers, applied twice a week for four weeks, found a greater granulation index than placebo, but inflammatory markers and bacterial counts did not clearly improve (PMID 37480520). A 2023 trial gave 238 hospital patients with Omicron COVID-19 an oral recombinant Lactococcus lactis that produces LL-37, and reported faster viral RNA clearance (9.8 versus 14.0 days) with no severe adverse events (PMID 37605995). That was open-label, and the abstract gives no dose in micrograms.

Why topical doses do not convert into an injection dose

People often want the "per kilogram" or "per milliliter" version converted into a syringe number. You cannot do it honestly. A 0.5 mg/mL gel is 500 mcg per milliliter of product, but the abstracts do not say how much was spread across how large a wound, and the peptide acted at the wound surface, not in the blood. Nothing in those trials tells you how much reaches a tissue after a subcutaneous injection, how fast it is broken down, or what a safe systemic level is.

There are two reasons to be wary rather than curious. First, LL-37 is double-edged. It is overexpressed in psoriasis, where two-thirds of patients with moderate-to-severe plaque disease carried T cells specific for it (PMID 25470744), and excess LL-37 drives rosacea-like inflammation in a mouse model (PMID 33734592). Second, the one clean dose-response result in humans showed a ceiling: the highest concentration stopped working. Nobody has mapped where, or whether, a systemic equivalent of that ceiling sits.

So where do 100 to 250 mcg a day come from? Mostly from each other. The three top-ranking dosage pages we read arrive at figures between 100 and 125 mcg once daily, and the ones that cite sources say the figure is community-derived. One calls it anecdotal outright. It is a convention that spread, not a number derived from the trials above.

What Reddit users report taking

To see what people do, I read 279 posts and comments from 13 threads across 7 communities, collected for this page. Only 24 items name LL-37 at all. Most of the rest is about SIBO treatments, KPV, SS-31 or long COVID in general. After removing questions, bots, copied explainers and secondhand rumor, 5 comments or posts were usable first-hand accounts of using LL-37: four in r/SIBO and one in r/covidlonghaulers. Two named a daily dose. That is far too small to call a pattern, so treat what follows as a handful of stories.

The two stated daily amounts were 250 mcg and 200 mcg. A r/SIBO commenter (Feb 2026) described a doctor-supervised plan: "I’m 2 weeks in to a protocol with a doctor, 250mcg daily for 30 days. I’ve felt so off and feel like brain fog worsened." (link). They put it down to die-off and had high mycotoxin and heavy-metal results on labs. That interpretation is theirs and is unverified. A separate commenter (Mar 2026) relayed a friend's advice of 100 mcg for 50 days and said they would start at 25 mcg, which is a plan, not an outcome, and not a first-hand account.

The other accounts did not give doses. One person took LL-37 once and described a partial benefit, mostly mental. Another tried it twice and wrote: "LL increased my inflammation & with knees and joints it made & caused sleepless painful nights." (link) (a r/SIBO commenter, Dec 2025). A reply questioned whether joint inflammation could appear within days. The covidlonghaulers poster used LL-37 as one of six peptides in a three-month practitioner protocol, introduced one at a time, and could not separate its effect from the others; swollen lymph nodes appeared during the introduction phase of some of them.

One account needs an explicit flag. A r/SIBO commenter (Sep 2025) said LL-37 helped chronic sinusitis and described the method: "Used in spray, 200 mcg daily, reconstituted with colloid silver water" (link). That is an unverified claim of a cure, and mixing a peptide into colloidal silver is not something any source here supports. It is an outlier, not evidence.

The broader mood is caution. Several people owned a vial and had not started, one was told by an immunologist to avoid immune-regulating peptides until testing was done, and others had not seen anyone succeed with LL-37 for SIBO. Another commenter simply advised against using it for more than 10 days, with no context or source. Three posted reference charts add to the picture without adding data: a 2023 profile post listing 100 to 200 mcg once or twice daily, an August 2026 cheat sheet with 100 mcg daily for 5 weeks, and an August 2026 post that describes itself as an AI-assisted synthesis. That last one also lists 50 to 100 mcg per kilogram. For a 70 kg adult that is 3.5 to 7 mg a day, 35 to 70 times its own flat 100 mcg figure, which tells you how loose these charts are.

Reconstitution math: mg, mL and syringe units

The vial holds a fixed mass of freeze-dried powder. Water changes the concentration, not the amount. The formula is: units on a U-100 syringe = dose in mcg ÷ concentration in mcg/mL × 100.

A worked example: a 10 mg vial reconstituted with 2 mL of bacteriostatic water is 10,000 mcg in 2 mL, or 5,000 mcg/mL. A 100 mcg dose is 100 ÷ 5,000 = 0.02 mL, which is 2 units on a syringe where 100 units equals 1 mL. Two units is a very small draw to measure accurately, which is why people add more water. With 5 mL the same vial is 2,000 mcg/mL and 100 mcg becomes 5 units.

Scaling by vial size is plain division. A 10 mg vial holds 100 doses of 100 mcg, 50 doses of 200 mcg or 40 doses of 250 mcg. A 5 mg vial holds half of each. The 50-day course in the relayed advice would use 5 mg at 100 mcg a day, and the 30-day plan at 250 mcg would use 7.5 mg.

There is a catch the dose charts skip. Sources disagree on how long reconstituted LL-37 lasts: about a week in our own overview guide, 28 days on several dosing pages, and 4 to 6 weeks in a Reddit post. We found no stability study. A 10 mg vial at 100 mcg a day lasts 100 days, longer than any of those windows, so either much of the vial is wasted or the material sits past its stated shelf life. If you want a single supplier to check a certificate against, Ascension Peptides sells an LL-37 10 mg vial at $78.00 as of 2026-10-11 ($7.80 per mg, down from a $119.99 list price). Kovera Labs tests every batch (HPLC, LC-MS identity, net content, endotoxin, sterility and heavy metals), more than 98 percent of tested batches pass, and batch certificates are public. Prices are in US dollars, shipping is US only and all sales are final. New customers can use code PEPTIDEDECK for 50 percent off. Our guide to buying LL-37 covers how to read a certificate of analysis.

Mcg and mg slips are the most dangerous error here: 0.1 mg and 100 mg differ a thousandfold, so write units out in full.

Timing, frequency and cycle length

There is no tested schedule, so what follows is what the sources say rather than what to do. The trials dosed twice a week for four weeks, topically. The Reddit accounts and posted charts describe once-daily use, sometimes twice, for 30 days, 5 weeks or 50 days. One chart suggests a break of equal length afterwards. Nobody cites evidence for it.

On timing within the day, the Reddit comments gave nothing useful. One chart says morning, on an empty stomach, which is convention. Two commenters stressed going slowly: one planned to start at 25 mcg, another said they would proceed extremely slowly, in threads where die-off reactions were the main worry.

Cycle length is the weakest area. The longest controlled human exposure is four weeks of topical use. Anything longer, and anything systemic, rests on forum habit. The comment advising a maximum of 10 days and the chart advising 4 to 8 weeks cannot both be right, and no source decides between them.

What changes the dose

These variables are said to matter; none can be quantified for injection.

Route. A wound gel, an oral bacterial delivery system, a nasal spray and a subcutaneous injection are different experiments. The one human result that is dose-dependent is topical.

Condition. People using LL-37 for gut or sinus problems cite the antimicrobial mechanism, but none of those uses has a human trial. Anyone with psoriasis, rosacea, an autoimmune condition or a cancer history has specific reasons for caution, because LL-37 is implicated in those conditions. See our page on LL-37 and KPV for how it differs from the anti-inflammatory peptide it is usually stacked with.

Stacks. Commenters ask whether LL-37 can share a syringe with BPC-157 or thymosin alpha-1. One said they would keep injections separate. No source here tests either option, and a blend vial with several peptides needs its numbers divided before comparing to any single-peptide figure.

Product quality. If the vial contains less than the label says, every calculation above is wrong. At 37 amino acids, LL-37 is a long chain to synthesize cleanly, so purity and content matter more than they do for short peptides.

Regulatory status. LL-37 is not FDA-approved. A May 2026 legal analysis reports that on April 15, 2026 FDA identified it among five peptides it plans to remove from its Category 2 list of bulk substances with significant safety concerns, with an advisory committee review expected before February 2027, and notes that removal does not make it eligible for compounding. We could not confirm anything newer, so treat the current status as unverified and ask a clinician.

Frequently Asked Questions

What is the LL-37 dosage?

There is no established LL-37 dosage for people. Human trials used topical concentrations of 0.5, 1.6 and 3.2 mg/mL on wounds, and the best results came at the lower two. The 100 to 125 mcg a day figure online is community convention, and the Reddit users who named a dose said 200 to 250 mcg a day.

How many units of LL-37 is 100 mcg?

It depends on the water you added. With a 10 mg vial and 2 mL the concentration is 5 mg/mL, so 100 mcg is 0.02 mL, or 2 units on a U-100 syringe. With 4 mL it is 4 units and with 5 mL it is 5 units. Divide the dose by the concentration, then multiply by 100.

How long do people run LL-37?

Reddit accounts and posted charts mention 10 days, 30 days, 5 weeks and 50 days, plus a 3-month multi-peptide protocol. The longest controlled human exposure we found was four weeks of topical use. No study defines a cycle length for injection.

Is LL-37 dosed by body weight?

In community charts the usual figure is flat. One AI-assisted post lists 50 to 100 mcg per kilogram, which would be 3.5 to 7 mg a day for a 70 kg adult, far above everything else on this page. No source tests weight-based dosing in people.

Is LL-37 legal and FDA-approved?

It is not FDA-approved for any use and is sold as a research chemical. Per a May 2026 legal summary, FDA planned to remove it from a bulk-substances safety list, which does not make it compoundable. We have not verified anything more recent.

Checking a vial before you do any math

The dose math assumes the label is true, so confirm lot, purity and mass first. Ascension Peptides lists the LL-37 10 mg vial at $78.00 as of 2026-10-11, with per-batch Kovera Labs testing and public batch certificates; US shipping only and all sales are final. Write units out in full, and treat every Reddit number here as an anecdote.