LL-37 vs TB-500 (Thymosin Beta-4)
Updated July 21, 2026 · Reviewed by the PeptidesDB Editorial team
A data-driven comparison of LL-37 and TB-500 (Thymosin Beta-4) (also searched as TB-500 (Thymosin Beta-4) vs LL-37) — effect profiles, evidence, side effects, and which suits weight loss, muscle, or healing goals.
Verdict
LL-37 centers on healing, while TB-500 (Thymosin Beta-4) leans toward healing. On indexed research, LL-37 is ahead (LL-37: 5 studies, Human evidence; TB-500 (Thymosin Beta-4): 3, Preclinical). Choose by goal — and read the primary studies. This is research information, not medical advice.
Key takeaways
- •LL-37 is strongest for healing; TB-500 (Thymosin Beta-4) for healing.
- •Evidence: LL-37 Human evidence (5 studies) vs TB-500 (Thymosin Beta-4) Preclinical (3).
- •Both are research-use compounds — not FDA-approved.
Effect profiles, overlaid
At a glance
Human Cathelicidin | Antimicrobial Peptide
LL-37 vs TB-500 (Thymosin Beta-4): side-by-side
| Metric | LL-37 | TB-500 (Thymosin Beta-4) |
|---|---|---|
| Class | Immune | — |
| Regulatory status | Research use only | Research use only |
| Evidence grade | Human evidence | Preclinical |
| Studies indexed | 5 | 3 |
| Research level | Well Studied | — |
| Strongest effect | Healing & recovery | Healing & recovery |
| Healing & recovery | 5.0▲ | 4.0 |
| Muscle & body comp | 0.0 | 3.0▲ |
| Metabolic & appetite | 0.0 | 2.0▲ |
| Neuro & mood | 0.0 | 1.0▲ |
| Sleep & circadian | 0.0 | 1.0▲ |
| Inflammation & immune | 4.0▲ | 4.0▲ |
| Skin & aesthetics | 0.0 | 2.0▲ |
▲ marks the higher community effect score (0–5 perceived-effect signal, not clinical efficacy).
Mechanism & pharmacokinetics
| Property | LL-37 | TB-500 (Thymosin Beta-4) |
|---|---|---|
| Mechanism | — | Actin-sequestering peptide; promotes cell migration & angiogenesis |
| Route | — | Subcutaneous injection (research use) |
Established pharmacology — curated for well-characterized compounds and AI-summarized otherwise. A blank (—) means no reliable single value is published (half-life figures for some peptides genuinely disagree across sources). Verify against primary sources such as FDA labels and ClinicalTrials.gov.
What is LL-37?
### LL-37 Summary LL-37 is a human cathelicidin antimicrobial peptide that plays a crucial role in the innate immune response, exhibiting antimicrobial, immunomodulatory, and wound healing properties. Its diverse functions make it a subject of interest in various fields of biomedical research.
Full LL-37 profile, mechanism & studies →What is TB-500 (Thymosin Beta-4)?
### Summary TB-500, a synthetic derivative of thymosin beta-4, is a peptide that has garnered attention for its potential role in tissue repair and regeneration. Research into TB-500 is ongoing, particularly regarding its applications in equine medicine and its implications in doping control.
Full TB-500 (Thymosin Beta-4) profile, mechanism & studies →Which is better for your goal?
| Goal | Better fit | Why |
|---|---|---|
| Healing | LL-37 | 5.0/5 effect signal |
| Muscle | TB-500 (Thymosin Beta-4) | 3.0/5 effect signal |
| Metabolic | TB-500 (Thymosin Beta-4) | 2.0/5 effect signal |
| Neuro | TB-500 (Thymosin Beta-4) | 1.0/5 effect signal |
| Sleep | TB-500 (Thymosin Beta-4) | 1.0/5 effect signal |
| Inflammation | Even | Both ~4.0/5 |
| Skin | TB-500 (Thymosin Beta-4) | 2.0/5 effect signal |
Fit reflects community-perceived effect profiles — not head-to-head trials. Read each peptide's studies before deciding.
Can you stack LL-37 and TB-500 (Thymosin Beta-4)?
People sometimes combine peptides that target different pathways, but there is little controlled research on this specific pairing and the interactions aren't well characterized. Because neither compound is FDA-approved, we don't publish stacking or dosing protocols here. Any combination should be discussed with a qualified clinician.
LL-37 vs TB-500 (Thymosin Beta-4): side effects
No community-reported effects logged yet.
No community-reported effects logged yet.
Anonymous community reports (count = number of reports), not clinical incidence rates.
What the research says
LL-37 has 5 approved studies indexed (Human evidence), and TB-500 (Thymosin Beta-4) has 3 (Preclinical). The Librarian re-checks PubMed, Europe PMC and ClinicalTrials daily, so these counts move. Open each profile to read the summaries and sources.
Frequently asked questions
Is LL-37 or TB-500 (Thymosin Beta-4) better?
It depends on your goal. LL-37 is strongest for healing; TB-500 (Thymosin Beta-4) for healing. LL-37 has more indexed studies (5). See the goal-by-goal breakdown above.
Is LL-37 or TB-500 (Thymosin Beta-4) better for weight loss?
TB-500 (Thymosin Beta-4) shows the stronger metabolic & appetite profile (2.0/5) in community effect data — though weight-loss outcomes depend on the individual and the evidence base.
Is LL-37 or TB-500 (Thymosin Beta-4) better for muscle?
TB-500 (Thymosin Beta-4) leads on the muscle & body-composition axis (3.0/5).
Which has more research, LL-37 or TB-500 (Thymosin Beta-4)?
LL-37 has 5 approved studies indexed (Human evidence); TB-500 (Thymosin Beta-4) has 3 (Preclinical). Higher counts mean more to read, not proven superiority.
Can you stack LL-37 and TB-500 (Thymosin Beta-4)?
Some users combine peptides, but there's little controlled data on this specific pairing, and interactions aren't well characterized. We don't publish stacking protocols for compounds that aren't FDA-approved. Discuss any combination with a qualified clinician.
What are the side effects of LL-37 vs TB-500 (Thymosin Beta-4)?
LL-37: no community-reported effects logged yet. TB-500 (Thymosin Beta-4): none logged yet. These are anonymous reports, not incidence rates — see each profile.
Is LL-37 or TB-500 (Thymosin Beta-4) FDA-approved?
LL-37 is a research-use compound and is not FDA-approved. TB-500 (Thymosin Beta-4) is not FDA-approved. Research-use status is not a legal clearance to compound or use in humans.
Is TB-500 (Thymosin Beta-4) better than LL-37?
For healing, TB-500 (Thymosin Beta-4) has the edge; for healing, LL-37 does. Neither is universally "better" — it's goal-dependent, and both should be weighed against their evidence base above.
Comparing related peptides
Regulatory & legal status
LL-37 and TB-500 (Thymosin Beta-4) are research-use compounds and are not FDA-approved for human use. FDA approval and compounding rules for peptides change frequently, and research-use status is not a legal clearance for human use. The FDA does not review compounded drugs for safety, effectiveness, or quality. Verify current status with primary sources before acting. Last reviewed July 21, 2026.