Comparison
Hexarelin vs Thymosin Alpha-1
Side-by-side of Hexarelin 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.
Hexarelin
Hexarelin peptide is a ghrelin-receptor hexapeptide. Largest acute GH pulse in the GHRP class, highest cortisol and prolactin lift, CD36 cardioprotective sign.
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
Hexarelin
- •Synthetic hexapeptide GHS-R1a agonist; produces the largest acute GH pulse of the synthetic GHRP class
- •Independent CD36 signaling produces cardioprotective effects in rodent ischemia models, GH-independent
- •Pronounced tachyphylaxis: GH response attenuates over 2 to 4 weeks of daily dosing
- •More cortisol and prolactin elevation than GHRP-2 or ipamorelin
- •Anecdotal protocols use 100 to 200 mcg subcutaneously 1 to 2 times daily for 2 to 4 week pulses
- •Banned by WADA under S2; advanced through phase 2 trials but never reached registration
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 | Hexarelin | Thymosin Alpha-1 |
|---|---|---|
| Category | peptide | peptide |
| Also known as | Examorelin, EP-23905, His-D-2-methyl-Trp-Ala-Trp-D-Phe-Lys-NH2 | Talpha1, Ta1, Zadaxin, Thymalfasin |
| Half-life (hr) ↗ | 1 | 2 |
| Typical dose (mg) ↗ | 0.1 | 1.6 |
| Dosing frequency | 1-2x daily | 2x weekly |
| Routes | subcutaneous, intranasal, intravenous | subcutaneous, intramuscular |
| Onset (hr) | 0.25 | 24 |
| Peak (hr) | 0.5 | 168 |
| Molecular weight | 887.04 | 3108.32 |
| Molecular formula | C47H58N12O6 | C129H215N33O55 |
| Mechanism | Hexapeptide agonist of GHS-R1a producing acute GH release with cortisol and prolactin co-elevation. Independent CD36 binding produces GH-independent cardioprotective signaling in preclinical models. | 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; advanced through phase 2 trials in EU but never registered; research-use-only grey market; banned by WADA | 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 | banned | 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 | 140703-51-1 | 62304-98-7 |
| PubChem CID | 3037387 | 16130571 |
| Wikidata | Q5743550 | Q913854 |
Safety profile
Hexarelin
Common side effects
- water retention
- vivid dreams
- head pressure or flushing
- transient lethargy
- tingling at injection site
- moderate hunger
Contraindications
- pregnancy
- active malignancy
- history of pituitary tumor
- uncontrolled diabetes
- prolactin-sensitive states
Interactions
- CJC-1295: synergistic GH release; accelerates tachyphylaxis if used continuously(minor)
- sermorelin: additive GH release via parallel GHRH and ghrelin pathways(minor)
- insulin: sustained GH can blunt insulin sensitivity over weeks(moderate)
- corticosteroids: amplify cortisol load; blunt GH response(moderate)
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. Hexarelin is the right call when one of the conditionals below applies.
- → If your priority is growth-hormone axis, pick Hexarelin.
- → If your priority is cardiac function, pick Hexarelin.
- → If your priority is immune support, pick Thymosin Alpha-1.
- → If your priority is antiviral action, pick Thymosin Alpha-1.
Default choice: Thymosin Alpha-1. Wider use case, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for Hexarelin 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 Hexarelin and Thymosin Alpha-1?
Hexarelin 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, Hexarelin or Thymosin Alpha-1?
Hexarelin half-life is 1 hours; Thymosin Alpha-1 half-life is 2 hours.
Can you stack Hexarelin 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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