Comparison
Noopept vs Thymosin Alpha-1
Side-by-side of Noopept 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.
Noopept
Noopept cognitive enhancer profile: 10 to 30 mg dosage, dipeptide nootropic mechanism, memory effects, and how it compares to piracetam.
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
Noopept
- •Russian dipeptide nootropic developed in the 1990s, registered in Russia 2002 for cognitive impairment
- •Roughly 1,000-fold higher per-mg potency than piracetam; therapeutic dose 10 to 30 mg/day
- •Active metabolite cycloprolylglycine modulates AMPA receptors and increases NGF and BDNF in rodent hippocampus
- •Russian RCTs in stroke recovery and vascular cognitive impairment show modest improvements over 4 to 8 weeks
- •Western evidence base is essentially absent; healthy-adult enhancement trials have not been published
- •Unscheduled in the US but not approved for human consumption; UK is prescription-only since 2014
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 | Noopept | Thymosin Alpha-1 |
|---|---|---|
| Category | nootropic | peptide |
| Also known as | GVS-111, N-phenylacetyl-L-prolylglycine ethyl ester, Omberacetam | Talpha1, Ta1, Zadaxin, Thymalfasin |
| Half-life (hr) ↗ | 0.7 | 2 |
| Typical dose (mg) ↗ | 20 | 1.6 |
| Dosing frequency | 2 to 3 times daily, last dose before mid-afternoon | 2x weekly |
| Routes | oral, sublingual | subcutaneous, intramuscular |
| Onset (hr) | 0.5 | 24 |
| Peak (hr) | 1 | 168 |
| Molecular weight | 318.37 | 3108.32 |
| Molecular formula | C17H22N2O4 | C129H215N33O55 |
| Mechanism | Hydrolyzed to active metabolite cycloprolylglycine; AMPA receptor modulation, BDNF and NGF upregulation, antioxidant and antiexcitotoxic effects. | 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 | Approved in Russia and CIS states; prescription-only in UK; unscheduled and unapproved in US, EU varies | 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 in the US | Rx only via international approval or US compounding (no controlled-substance schedule) |
| Pregnancy | Not recommended | Not recommended; insufficient data |
| CAS | 157115-85-0 | 62304-98-7 |
| PubChem CID | 183503 | 16130571 |
| Wikidata | Q4321022 | Q913854 |
Safety profile
Noopept
Common side effects
- headache
- irritability
- sleep disturbance with late-day dosing
- occasional blood pressure elevation
Contraindications
- pregnancy
- lactation
- pediatric use
- severe hepatic impairment
- severe renal impairment
Interactions
- memantine and other glutamatergic agents: theoretical AMPA-pathway interaction(minor)
- antidepressants: theoretical effect via BDNF axis, undocumented(minor)
- antihypertensives: occasional blood pressure elevation may require monitoring(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. Noopept is the right call when one of the conditionals below applies.
- → If your priority is focus or working memory, pick Noopept.
- → If your priority is memory, pick Noopept.
- → If your priority is immune support, pick Thymosin Alpha-1.
- → If your priority is post-training recovery, pick Thymosin Alpha-1.
Edge case: If you cannot self-administer injections, Noopept is the only oral option in this pair.
Default choice: Thymosin Alpha-1. Wider use case, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for Noopept 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 Noopept and Thymosin Alpha-1?
Noopept and Thymosin Alpha-1 differ in category (nootropic vs peptide), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Noopept or Thymosin Alpha-1?
Noopept half-life is 0.7 hours; Thymosin Alpha-1 half-life is 2 hours.
Can you stack Noopept 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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