Comparison
Epitalon vs Thymosin Alpha-1
Side-by-side of Epitalon and Thymosin Alpha-1. Every row below is pulled from the compound schema and will update as our data grows. For deeper reads, follow through to each compound page.
Epitalon
Epitalon peptide (Epithalon, tetrapeptide AEDG): telomerase activation, lifespan extension data, anti-aging trials, dosage, half-life, and safety.
Thymosin Alpha-1
Thymosin alpha-1 peptide (Zadaxin, thymalfasin): 28-amino-acid TA1 immunomodulator. Dosing, T-cell effects, hepatitis B and HCV adjunct evidence.
Effects at a glance
Epitalon
- •Synthetic tetrapeptide (Ala-Glu-Asp-Gly) developed at the St. Petersburg Institute of Bioregulation
- •Russian clinical literature reports mortality reduction in elderly cohorts and improved melatonin output
- •Reported telomerase activation in human somatic cell culture and lifespan extension in mice and Drosophila
- •Independent Western replication is essentially absent; no FDA-standard RCTs
- •Anecdotal protocols use 5 to 10 mg subcutaneously daily for 10 to 20 day cycles, 2 to 4 times yearly
- •Not currently on the WADA Prohibited List
Thymosin Alpha-1
- •28-amino-acid synthetic peptide identical to thymic-derived immunomodulator
- •Approved in over 35 countries as Zadaxin for hepatitis B, hepatitis C adjunct, and immune support
- •Not FDA approved in US; compounded by 503A/503B pharmacies for off-label immune support
- •Modulates T-cell maturation, NK activity, and Th1 polarization in immunocompromised states
- •Standard label dose: 1.6 mg subcutaneously twice weekly
- •Cleanest safety profile in the peptide class with hundreds of regulated trials behind it
Side-by-side
| Attribute | Epitalon | Thymosin Alpha-1 |
|---|---|---|
| Category | peptide | peptide |
| Also known as | Epithalon, Ala-Glu-Asp-Gly, AEDG, Epithalamin (precursor extract) | Talpha1, Ta1, Zadaxin, Thymalfasin |
| Half-life (hr) ↗ | 0.5 | 2 |
| Typical dose (mg) ↗ | 5 | 1.6 |
| Dosing frequency | daily during cycle | 2x weekly |
| Routes | subcutaneous, intramuscular, intranasal | subcutaneous, intramuscular |
| Onset (hr) | 24 | 24 |
| Peak (hr) | 168 | 168 |
| Molecular weight | 390.35 | 3108.32 |
| Molecular formula | C14H22N4O9 | C129H215N33O55 |
| Mechanism | Synthetic tetrapeptide proposed to interact directly with DNA and chromatin to modulate tissue-specific gene expression. Reported effects include telomerase activation, increased melatonin output from pineal cells, and circadian normalization. | Synthetic peptide modulator of innate and adaptive immunity. Promotes T-cell maturation and CD4/CD8 production, modulates Th1/Th2 balance, stimulates NK cell activity, and modulates TLR2/TLR9 signaling in dendritic cells. |
| Legal status | Not FDA approved; registered in Russia under domestic pharmaceutical framework; research-use-only grey market in US/EU | Approved in 35+ countries as Zadaxin (hepatitis B, hepatitis C adjunct, immune support); not FDA approved in US; compounded by 503A/503B pharmacies for off-label use; not on WADA Prohibited List |
| WADA status | unknown | unknown |
| DEA / Rx | Not scheduled (research chemical) | Rx only via international approval or US compounding (no controlled-substance schedule) |
| Pregnancy | Insufficient data; not recommended | Not recommended; insufficient data |
| CAS | 307297-39-8 | 62304-98-7 |
| PubChem CID | 219042 | 16130571 |
| Wikidata | Q5384126 | Q913854 |
Safety profile
Epitalon
Common side effects
- injection-site reactions
- occasional mild headache (rare)
Contraindications
- pregnancy
- lactation
- active malignancy (theoretical telomerase concern)
- concurrent immunosuppression
Interactions
- melatonin: potential additive effect on circadian and pineal output; no controlled data(minor)
Thymosin Alpha-1
Common side effects
- mild injection-site irritation (rare)
- transient mild fatigue (rare)
- occasional headache (rare)
Contraindications
- pregnancy
- lactation
- active organ transplant rejection therapy
- systemic immunosuppression for autoimmune disease (relative)
- severe active autoimmune disease (caution)
Interactions
- interferon-alpha: additive immune effect; used clinically in approved combination protocols(minor)
- calcineurin inhibitors (cyclosporine, tacrolimus): theoretical destabilization of immunosuppression; avoid(major)
- antimetabolites (azathioprine, mycophenolate): theoretical destabilization of immunosuppression; avoid(major)
- vaccine administration: may augment vaccine response in elderly or immunocompromised; coordinate with clinician(minor)
Which Should You Take?
Thymosin Alpha-1 comes out ahead for most readers on the criteria we weight: 3 catalogued goals, Approved in 35+ countries as Zadaxin (hepatitis B, hepatitis C adjunct, immune support); not FDA approved in US; compounded by 503A/503B pharmacies for off-label use; not on WADA Prohibited List, with a Tier-A outcome catalogued. Epitalon is the right call when one of the conditionals below applies.
- → If your priority is healthspan extension, pick Epitalon.
- → If your priority is sleep onset or sleep quality, pick Epitalon.
- → If your priority is immune support, pick Thymosin Alpha-1.
- → If your priority is post-training recovery, pick Thymosin Alpha-1.
Edge case: Half-lives differ materially (Epitalon ~0.5 hr vs Thymosin Alpha-1 ~2 hr). Thymosin Alpha-1 reaches steady state faster; Epitalon is easier to dial in if tolerability is uncertain.
Default choice: Thymosin Alpha-1. Wider use case, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for Epitalon only if your priority sits squarely in the goals it owns above.
This verdict is generated from each compound's schema (goals, legal status, evidence outcomes, dosing route). It updates automatically as our compound data evolves; the deeper read sits on each individual compound page.
Common questions
What is the difference between Epitalon and Thymosin Alpha-1?
Epitalon and Thymosin Alpha-1 differ in category (peptide vs peptide), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Epitalon or Thymosin Alpha-1?
Epitalon half-life is 0.5 hours; Thymosin Alpha-1 half-life is 2 hours.
Can you stack Epitalon with Thymosin Alpha-1?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
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