LL-37 is a cathelicidin peptide. Splenopentin is a immune pentapeptide.
They are aimed at different things: LL-37 at antimicrobial & healing; Splenopentin at immune support.
| Comparison | LL-37 cathelicidin · hCAP-18 | Splenopentin SP-5 · splenopentin acetate |
|---|---|---|
| How it works | How it works LL-37 is part of your innate immune system, the fast general-purpose defence that acts before your body has identified what it is fighting. | How it works Splenopentin belongs to the same era and idea as thymopentin, and shares its problem. |
| What it is | A natural germ-fighting peptide for stubborn infections and wound healing. | A five-amino-acid spleen peptide, sold on an evidence base almost nobody has read. |
| Status | Research only | Research only |
| Typical dose | 0.1–0.5 mg per dose | — |
| How often | Daily, short courses | Not established |
| Stays active | Nothing published | Nothing published |
| Dose comes from | Community practice | No established range |
| Cycled? | Taken in daily, short courses Community practice | Not established No established range |
| What it does | ||
| Drug class | Cathelicidin peptide | Immune pentapeptide |
| Used for | A natural germ-fighting peptide used against stubborn infections, biofilms, and gut bugs, and to support wound healing. | An immune peptide sold for immune support and bone marrow recovery. |
| Receptors hit | — | — |
| Numbers | ||
| Full dose line | 0.1 up to 0.5 mg per dose (start low, increase slowly) | Research only |
| Why that cycle | Course dosing is how this one is normally used. Where the course length comes from is the thing to check: for most compounds in this pattern it is convention rather than a tested schedule. | No schedule has been studied for this compound in people. |
| Weight / effect | Not measured in a trial | Not measured in a trial |
| Chain length | 37 residues | 5 residues |
| Common vial | 5 mg | — |
| Before you start | ||
| Route | Under the skin (subcutaneous) | Under the skin (subcutaneous) |
| Do not use if | No established systemic safety profile Pregnancy Autoimmune conditions, as a theoretical precaution | Pregnancy or breastfeeding An autoimmune condition, without medical advice Cancer treatment, where an unstudied peptide is not a substitute for supportive care that has been tested Anyone who wants established safety data, because none exists for this compound in humans |
What separates them
Proof behind the dose. Every dose here comes from community practice. Not one is backed by a published human study, which is worth knowing before you read the numbers as if they were equivalent.
What doesn't differ: They are both taken the same way (under the skin). Neither has a measured effect size from a published trial, so there is no number to rank them on.
What people actually report
LL-37
- It can irritate the injection site, with a theoretical autoimmune concern, and there is little human data.
- Signs of an allergic reaction
- A spreading rash or worsening inflammation
Splenopentin
- The research behind it is old, small and largely unrepeated.
- It affects immune cells, which is not desirable in every condition.
- Signs of an allergic reaction, including spreading hives, facial or throat swelling, or trouble breathing
- Redness, heat, or pus at the injection site, which can signal infection
Side effects are what users and trials report most often, not a complete list. Anything sudden, spreading, or breathing-related is an emergency regardless of which compound caused it.
People also compare
This comparison does not cover cost, long-term safety, or how you personally will respond. Effect figures come from separate trials in different populations and are not always directly comparable to each other. Nothing here is medical advice or a recommendation to use any of these. Talk to a clinician about your own situation.