Comparison
Nicotinamide Riboside vs Thymosin Alpha-1
Side-by-side of Nicotinamide Riboside 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.
Nicotinamide Riboside
Nicotinamide riboside (NR) is the most-studied NAD+ precursor in humans. Sold as Niagen by Chromadex; raises plasma NAD+ 30-60% at 250-1,000 mg/day.
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
Nicotinamide Riboside
- •Most-studied NAD+ precursor in human trials; the original Niagen formulation by Chromadex
- •Plasma NAD+ rises 30-60% at 250-1,000 mg/day across multiple human PK trials
- •Martens 2018 reported reduced BP and arterial stiffness at 500 mg/day for 6 weeks
- •Dollerup 2018 found no insulin sensitivity change despite plasma NAD+ rise
- •Tissue NAD+ rise inconsistent; hard clinical endpoints not yet measured
- •Larger human safety database than NMN; comparable mechanistic effects
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 | Nicotinamide Riboside | Thymosin Alpha-1 |
|---|---|---|
| Category | supplement | peptide |
| Also known as | NR, Niagen, nicotinamide riboside chloride | Talpha1, Ta1, Zadaxin, Thymalfasin |
| Half-life (hr) ↗ | 8 | 2 |
| Typical dose (mg) ↗ | 500 | 1.6 |
| Dosing frequency | daily, typically morning | 2x weekly |
| Routes | oral | subcutaneous, intramuscular |
| Onset (hr) | 1 | 24 |
| Peak (hr) | 4 | 168 |
| Molecular weight | 255.25 | 3108.32 |
| Molecular formula | C11H15N2O5 | C129H215N33O55 |
| Mechanism | NAD+ precursor via salvage pathway. Phosphorylated to NMN by nicotinamide riboside kinase (NRK), then converted to NAD+. Substrate for sirtuins, PARPs, and CD38. | 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 | OTC dietary supplement | 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 | allowed | unknown |
| DEA / Rx | OTC supplement | Rx only via international approval or US compounding (no controlled-substance schedule) |
| Pregnancy | Insufficient data at supplement doses | Not recommended; insufficient data |
| CAS | 1341-23-7 | 62304-98-7 |
| PubChem CID | 439924 | 16130571 |
| Wikidata | Q3343054 | Q913854 |
Safety profile
Nicotinamide Riboside
Common side effects
- mild GI upset (rare)
- headache (rare)
Contraindications
- pregnancy / lactation (insufficient data)
- active cancer (theoretical, no contraindicating data)
Interactions
- pterostilbene: complementary sirtuin pathway (Basis combination)(minor)
- TMG (trimethylglycine): methylation support during high NAD+ precursor dosing(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?
Nicotinamide Riboside comes out ahead for most readers on the criteria we weight: 3 catalogued goals, OTC dietary supplement, oral dosing, with a Tier-A outcome catalogued. Thymosin Alpha-1 is the right call when one of the conditionals below applies.
- → If your priority is healthspan extension, pick Nicotinamide Riboside.
- → If your priority is energy and stamina, pick Nicotinamide Riboside.
- → 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 want to avoid 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, Nicotinamide Riboside is the more accessible choice.
Default choice: Nicotinamide Riboside. Lower friction to source, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for Thymosin Alpha-1 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 Nicotinamide Riboside and Thymosin Alpha-1?
Nicotinamide Riboside and Thymosin Alpha-1 differ in category (supplement vs peptide), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Nicotinamide Riboside or Thymosin Alpha-1?
Nicotinamide Riboside half-life is 8 hours; Thymosin Alpha-1 half-life is 2 hours.
Can you stack Nicotinamide Riboside 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.
Go deeper