LL-37 vs Melanotan II
Overview
LL-37 is primarily a immune support peptide, while Melanotan II is used for cosmetic & skin.
This page compares LL-37 and Melanotan II across their primary use, typical dosing, reported benefits and side effects, and U.S. regulatory status. For the full monograph on either compound — mechanism of action, clinical research, and references — follow the article links.
Side-by-side comparison
| LL-37 | Melanotan II | |
|---|---|---|
| Category | Immune Support | Cosmetic & Skin |
| Regulatory status (US) | Compounding (Rx) — Apr 2026 | Compounding (Rx) — Apr 2026 |
| Typical dosage | 2-5 mg | 250-500 mcg |
| Frequency | twice weekly | as needed |
| Reported benefits | Antimicrobial activity, immune modulation, wound healing, anti-inflammatory | Skin tanning without UV exposure, increased libido, potential appetite suppression |
| Reported side effects | Generally safe, minimal side effects | Nausea, facial flushing, darkening of moles, potential cardiovascular effects |
Key differences
Primary use. LL-37 is categorised under Immune Support, while Melanotan II falls under Cosmetic & Skin. Their differing categories mean they are usually chosen for different goals rather than as direct substitutes.
Regulatory status. LL-37: not FDA-approved; compounding permitted with a prescription as of April 2026. Melanotan II: not FDA-approved; compounding permitted with a prescription as of April 2026.
Dosing. LL-37 is typically dosed at 2-5 mg (twice weekly). Melanotan II is typically dosed at 250-500 mcg (as needed).
Can you stack them?
Some protocols combine peptides, but stacking LL-37 and Melanotan II has not been validated for safety or efficacy in controlled trials. Combining compounds can change their effects and risks. Nothing here is medical advice — consult a qualified healthcare provider before starting or combining any protocol.
Frequently asked questions
- What is the difference between LL-37 and Melanotan II?
- LL-37 is primarily a immune support peptide, while Melanotan II is used for cosmetic & skin. LL-37 is not FDA-approved; compounding permitted with a prescription (as of April 2026), whereas Melanotan II is not FDA-approved; compounding permitted with a prescription (as of April 2026).
- What is LL-37 used for?
- Antimicrobial defense peptide.
- What is Melanotan II used for?
- Tanning, libido.
- Can you take LL-37 and Melanotan II together?
- Some users combine peptides within a single protocol, but stacking LL-37 and Melanotan II has not been established as safe or effective in controlled trials. Neither this comparison nor PeptideSciences101 is medical advice — consult a qualified healthcare provider before combining any compounds.
- Is LL-37 or Melanotan II FDA-approved?
- LL-37 is not FDA-approved; compounding permitted with a prescription (as of April 2026). Melanotan II is not FDA-approved; compounding permitted with a prescription (as of April 2026).
Read the full articles
- LL-37 — full monograph: mechanism, research, dosing & references
- Melanotan II — full monograph: mechanism, research, dosing & references