Larazotide vs Thymosin Beta-4
A neutral, side-by-side comparison of two healing & recovery peptides — their mechanisms, dosing ranges, administration routes, side effects, and research evidence. For research and educational purposes only.
Larazotide
Larazotide (AT-1001) is a synthetic octapeptide that acts as a tight junction regulator — it competitively blocks zonulin, the primary physiological driver of intestinal permeability ('leaky gut'). It is one of the few compounds studied in human clinical trials specifically for tight junction dysfunction, with Phase 2 data in celiac disease demonstrating reduced intestinal permeability and symptom improvement even in the presence of ongoing gluten exposure.
Full profileThymosin Beta-4
Thymosin Beta-4 (TB4) is the full-length 43-amino acid peptide produced naturally in high concentrations in platelets, wound fluid, and regenerating tissue. It is the parent molecule from which the popular TB-500 research peptide (the 17-23 fragment Ac-LKKTETQ) is derived. TB4 promotes actin polymerization, accelerates wound healing, reduces inflammation, and supports cardiac and neurological repair in preclinical models.
Full profile| Larazotide | Thymosin Beta-4 | |
|---|---|---|
| Category | Healing & Recovery | Healing & Recovery |
| Also known as | Larazotide acetate, AT-1001, INN-202 | TB4, Tβ4, Tβ4 full-length |
| Evidence | FDA-approved | Investigational (in trials) |
| Dosing range | 0.25mg–1mg mg, 3x daily (before meals) | 500mcg–2000mcg mcg, 2–3x weekly |
| Administration | Oral (capsule), Subcutaneous injection (research use) | Subcutaneous injection, Intramuscular injection, Intravenous (clinical studies only) |
| Key side effects | Headache (most commonly reported adverse event in trials), Nausea (mild), Generally well-tolerated — adverse event rate similar to placebo in clinical trials | Injection site discomfort (mild), Transient fatigue post-injection, Headache (uncommon), Theoretically may accelerate growth of pre-existing malignant tumors (promotes angiogenesis and cell migration — use with caution) |
| Cited sources | 3 references | 3 references |
Key differences
- Evidence level differs: Larazotide is fda-approved, while Thymosin Beta-4 is investigational (in trials).
- Administration: Larazotide — Oral (capsule), Subcutaneous injection (research use); Thymosin Beta-4 — Subcutaneous injection, Intramuscular injection, Intravenous (clinical studies only).
- Dosing units differ: Larazotide is dosed in mg, Thymosin Beta-4 in mcg — they operate at different scales.
- Frequency: Larazotide is typically 3x daily (before meals); Thymosin Beta-4 is 2–3x weekly.
How each works
Larazotide
Zonulin upregulation disrupts the tight junction proteins occludin and claudin, allowing paracellular passage of antigens, LPS, and inflammatory triggers into systemic circulation. Larazotide acts as a tight junction agonist by competitively displacing zonulin from its receptor and directly stabilizing tight junction complexes. The Phase 2b CeD trial (N=342) showed larazotide reduced the ratio of lactulose/mannitol (L/M ratio, standard intestinal permeability marker) and improved GI symptom scores versus placebo in actively-challenged celiac patients.
Thymosin Beta-4
TB4's primary mechanism involves sequestering G-actin monomers (via its LKKTET actin-binding domain) to regulate actin cytoskeleton dynamics — critical for cell migration, wound closure, and tissue remodeling. Clinical trials have evaluated TB4 for corneal wound healing (Phase 2), pressure ulcers, and cardiac repair after MI. The FACT trial investigated TB4 in patients with ischemic heart failure, showing trends toward improved cardiac function. Anti-inflammatory effects are mediated partly through NF-κB pathway downregulation.
This comparison aggregates public research and structured profile data for informational purposes only. It is not medical advice and does not recommend either compound for human use. Consult a qualified healthcare provider before considering any peptide.