Comparison
CJC-1295 vs Thymosin Alpha-1
Side-by-side of CJC-1295 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.
CJC-1295
CJC-1295 peptide profile: GHRH analog forms (with-DAC ~7-day half-life, no-DAC Mod GRF 1-29 ~30 min), ipamorelin pairing, recovery use, dosing, side effects.
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
CJC-1295
- •GHRH analog that binds the GHRH receptor on pituitary somatotrophs to release endogenous GH
- •DAC variant has ~7 day half-life via albumin binding; non-DAC variant ~30 minutes
- •Teichman 2006 trial showed sustained 2 to 10 fold IGF-1 elevation at 60 to 250 mcg/kg DAC dosing
- •Anecdotal protocols pair non-DAC CJC-1295 with Ipamorelin to mimic pulsatile GH release
- •Side effects: water retention, numbness or tingling at injection site, vivid dreams, transient flushing
- •No completed phase III RCTs; research-use-only and not FDA approved
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 | CJC-1295 | Thymosin Alpha-1 |
|---|---|---|
| Category | peptide | peptide |
| Also known as | CJC-1295 DAC, CJC-1295 no-DAC, Mod GRF 1-29, tesamorelin analog | Talpha1, Ta1, Zadaxin, Thymalfasin |
| Half-life (hr) ↗ | 168 | 2 |
| Typical dose (mg) ↗ | 0.1 | 1.6 |
| Dosing frequency | weekly (DAC); 1-3x daily (non-DAC) | 2x weekly |
| Routes | subcutaneous | subcutaneous, intramuscular |
| Onset (hr) | 1 | 24 |
| Peak (hr) | 3 | 168 |
| Molecular weight | 3367.83 | 3108.32 |
| Molecular formula | C152H252N44O42 | C129H215N33O55 |
| Mechanism | Binds the GHRH receptor on pituitary somatotrophs, stimulating pulsatile growth-hormone release. The DAC modification extends plasma residence by tethering the peptide to serum albumin via a maleimide-cysteine bond. | 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; 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 FDA approved; not scheduled; research-chemical status | Rx only via international approval or US compounding (no controlled-substance schedule) |
| Pregnancy | Insufficient data; not recommended | Not recommended; insufficient data |
| CAS | 446262-90-4 | 62304-98-7 |
| PubChem CID | 91971820 | 16130571 |
| Wikidata | Q5012154 | Q913854 |
Safety profile
CJC-1295
Common side effects
- injection-site reactions
- water retention
- numbness or tingling at injection site
- vivid dreams
- transient flushing
- head pressure or mild headache
Contraindications
- pregnancy
- active malignancy
- diabetic retinopathy (theoretical)
- history of pituitary tumor
Interactions
- Ipamorelin: synergistic GH release; commonly co-administered in anecdotal protocols(minor)
- insulin: GH-induced insulin resistance can shift glycemic control over weeks(moderate)
- corticosteroids: blunt GH-axis response; reduce expected efficacy(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. CJC-1295 is the right call when one of the conditionals below applies.
- → If your priority is growth-hormone axis, pick CJC-1295.
- → If your priority is body composition, pick CJC-1295.
- → If your priority is immune support, pick Thymosin Alpha-1.
- → If your priority is antiviral action, pick Thymosin Alpha-1.
Edge case: Half-lives differ materially (CJC-1295 ~168 hr vs Thymosin Alpha-1 ~2 hr). CJC-1295 reaches steady state faster; Thymosin Alpha-1 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 CJC-1295 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 CJC-1295 and Thymosin Alpha-1?
CJC-1295 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, CJC-1295 or Thymosin Alpha-1?
CJC-1295 half-life is 168 hours; Thymosin Alpha-1 half-life is 2 hours.
Can you stack CJC-1295 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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