Comparison
NMN vs Spermidine
Side-by-side of NMN and Spermidine. 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.
NMN
NMN supplements are oral nicotinamide mononucleotide capsules sold for longevity, energy, and metabolic health. They raise plasma NAD+ 30-90% at 250-1000.
Spermidine
Spermidine supplement benefits cover autophagy induction, longevity signals, and cognition. Wheat germ extract data, doses, and human trials reviewed.
Effects at a glance
NMN
- •Plasma NAD+ rises 30-90% at 250-1000 mg/day across human PK studies
- •Tissue NAD+ rise is inconsistent across human trials (Yoshino 2021, Igarashi 2022)
- •No human trials measure hard endpoints (mortality, CV events, cancer); evidence is biomarker-only
- •Most trials cluster at 250-500 mg/day; dose-response above 250 mg/day is poorly characterized
- •FDA position contested; widely sold as supplement but with regulatory uncertainty
- •Marketing claims for fertility and longevity outrun the human trial evidence substantially
Spermidine
- •Endogenous polyamine that induces autophagy via EP300 acetyltransferase inhibition and TFEB activation
- •Concentrated in wheat germ, soybeans, aged cheese, and mushrooms; ~10 to 15 mg/day in Mediterranean diets
- •Eisenberg 2016 reported dietary spermidine extended mouse lifespan and improved cardiac function
- •Wirth 2018 pilot (n=28) reported cognitive signal at 0.9 mg/day in older adults at risk for dementia
- •Larger Wirth 2019 follow-up (n=85) did not replicate the memory benefit at 12 months
- •Generally regarded as safe at supplemental doses; food-source position is reassuring
Side-by-side
| Attribute | NMN | Spermidine |
|---|---|---|
| Category | supplement | supplement |
| Also known as | nicotinamide mononucleotide, beta-NMN | spermidine trihydrochloride, wheat-germ-extract spermidine |
| Half-life (hr) ↗ | 4 | 6 |
| Typical dose (mg) ↗ | 250 | 1.2 |
| Dosing frequency | 1x daily, often morning | daily, typically morning with food |
| Routes | oral, sublingual | oral |
| Onset (hr) | 1 | 2 |
| Peak (hr) | 3 | 4 |
| Molecular weight | 334.22 | 145.25 |
| Molecular formula | C11H15N2O8P | C7H19N3 |
| Mechanism | Direct precursor in the NAD+ salvage pathway; converted to NAD+ by NMNAT enzymes in essentially every tissue. Raised NAD+ supports sirtuin and PARP enzyme activity. | Induces macroautophagy via inhibition of EP300 histone acetyltransferase and activation of TFEB-mediated lysosomal biogenesis. Substrate for hypusination of eIF5A, required for translation of mitochondrial respiration proteins. |
| Legal status | Contested in US (FDA position 2022); widely sold as supplement; broadly available in EU, UK, Asia | OTC dietary supplement (wheat-germ extract has GRAS status in US) |
| WADA status | allowed | allowed |
| DEA / Rx | Not scheduled | OTC supplement (not scheduled) |
| Pregnancy | Insufficient data; precautionary avoidance | Insufficient data; not routinely recommended at supplemental doses |
| CAS | 1094-61-7 | 124-20-9 |
| PubChem CID | 14180 | 1102 |
| Wikidata | Q418972 | Q411089 |
Safety profile
NMN
Common side effects
- mild GI upset (rare)
- occasional headache
- flushing (rare)
Contraindications
- pregnancy and lactation (precautionary, no data)
- active cancer (theoretical concern, not evidence-based)
Interactions
- metformin: no clinically significant interaction documented; both modulate metabolism through different mechanisms(minor)
- chemotherapy agents: theoretical concern about supporting cancer cell proliferation; coordinate with oncology team(moderate)
- CD38 inhibitors: would amplify NMN-induced NAD+ rise; not clinically relevant for most users(minor)
Spermidine
Common side effects
- mild GI upset (rare)
- headache (rare)
Contraindications
- wheat-germ allergy or celiac disease (for wheat-germ-extract products)
- active cancer (theoretical)
- pregnancy and lactation (insufficient data)
Interactions
- DFMO (difluoromethylornithine): competing polyamine metabolism; do not combine without oncology guidance(moderate)
Which Should You Take?
Spermidine comes out ahead for most readers on the criteria we weight: 2 catalogued goals, OTC dietary supplement, oral dosing, with a Tier-A outcome catalogued. NMN is the right call when one of the conditionals below applies.
- → If your priority is energy and stamina, pick NMN.
- → If your priority is metabolic health and glucose control, pick NMN.
- → If your priority is focus or working memory, pick Spermidine.
Edge case: If you want to avoid Contested in US (FDA position 2022); widely sold as supplement; broadly available in EU, UK, Asia, Spermidine is the more accessible choice.
Default choice: Spermidine. Lower friction to source, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for NMN 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 NMN and Spermidine?
NMN and Spermidine differ in category (supplement vs supplement), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, NMN or Spermidine?
NMN half-life is 4 hours; Spermidine half-life is 6 hours.
Can you stack NMN with Spermidine?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
Go deeper