LL-37 vs Thymalin
Overview
LL-37 and Thymalin are both immune support peptides, but they differ in mechanism, dosing, and regulatory status.
This page compares LL-37 and Thymalin 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 | Thymalin | |
|---|---|---|
| Category | Immune Support | Immune Support |
| Regulatory status (US) | Compounding (Rx) — Apr 2026 | Research use only |
| Typical dosage | 2-5 mg | 10 mg |
| Frequency | twice weekly | daily for 10-day cycles |
| Reported benefits | Antimicrobial activity, immune modulation, wound healing, anti-inflammatory | Thymus rejuvenation, immune enhancement, anti-aging immune support |
| Reported side effects | Generally safe, minimal side effects | Well-tolerated during cycles |
Key differences
Primary use. LL-37 is categorised under Immune Support, while Thymalin falls under Immune Support. Because they target a similar goal, they are common alternatives to weigh against each other.
Regulatory status. LL-37: not FDA-approved; compounding permitted with a prescription as of April 2026. Thymalin: not FDA-approved; treated as a research compound.
Dosing. LL-37 is typically dosed at 2-5 mg (twice weekly). Thymalin is typically dosed at 10 mg (daily for 10-day cycles).
Can you stack them?
Some protocols combine peptides, but stacking LL-37 and Thymalin 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 Thymalin?
- LL-37 and Thymalin are both immune support peptides, but they differ in mechanism, dosing, and regulatory status. LL-37 is not FDA-approved; compounding permitted with a prescription (as of April 2026), whereas Thymalin is not FDA-approved; generally classified as a research compound.
- What is LL-37 used for?
- Antimicrobial defense peptide.
- What is Thymalin used for?
- Thymus restoration peptide.
- Can you take LL-37 and Thymalin together?
- Some users combine peptides within a single protocol, but stacking LL-37 and Thymalin 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 Thymalin FDA-approved?
- LL-37 is not FDA-approved; compounding permitted with a prescription (as of April 2026). Thymalin is not FDA-approved; generally classified as a research compound.