Larazotide vs Thymosin Alpha-1
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 Alpha-1
Thymosin Alpha-1 (Tα1) is a 28-amino acid peptide naturally derived from the thymus gland. It plays a central role in regulating immune function — specifically in the maturation and differentiation of T-cells. Unlike most research peptides, Thymosin Alpha-1 has approved clinical use in multiple countries (China, Italy, and others) for hepatitis B, hepatitis C, and as an immune adjuvant in cancer patients undergoing chemotherapy. In the US it is sold as Zadaxin and used as a research compound.
Full profile| Larazotide | Thymosin Alpha-1 | |
|---|---|---|
| Category | Healing & Recovery | Healing & Recovery |
| Also known as | Larazotide acetate, AT-1001, INN-202 | Tα1, Thymalfasin, Zadaxin |
| Evidence | FDA-approved | Research-stage |
| Dosing range | 0.25mg–1mg mg, 3x daily (before meals) | 900mcg–3.2mg mg, 2–3 times per week subcutaneously |
| Administration | Oral (capsule), Subcutaneous injection (research use) | Subcutaneous injection |
| 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 | Generally very well tolerated, Mild injection site reactions (most common), Transient fatigue in initial doses, Flu-like symptoms (rare) |
| Cited sources | 3 references | 4 references |
Key differences
- Evidence level differs: Larazotide is fda-approved, while Thymosin Alpha-1 is research-stage.
- Administration: Larazotide — Oral (capsule), Subcutaneous injection (research use); Thymosin Alpha-1 — Subcutaneous injection.
- Frequency: Larazotide is typically 3x daily (before meals); Thymosin Alpha-1 is 2–3 times per week subcutaneously.
- Research depth: this profile cites 3 sources for Larazotide vs 4 for Thymosin Alpha-1.
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 Alpha-1
Extensive human clinical research documents Tα1's immune-modulating effects. It increases T-cell counts, enhances NK cell activity, and promotes Th1 cytokine balance. Multiple randomized trials have shown efficacy in treating chronic hepatitis B and C, reducing infection severity in critically ill patients, and improving outcomes in sepsis. More recent research investigates its role in long COVID immune dysregulation. It is considered one of the best-studied peptides in immunology.
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.