Comparison
Spermidine vs TUDCA
Side-by-side of Spermidine and TUDCA. 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.
Spermidine
Spermidine supplement benefits cover autophagy induction, longevity signals, and cognition. Wheat germ extract data, doses, and human trials reviewed.
TUDCA
TUDCA is the taurine-conjugated form of ursodeoxycholic acid, a bile-acid molecule with replicated effects on liver function, ER stress, and bile flow.
Effects at a glance
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
TUDCA
- •Bile-acid molecule (taurine-conjugated UDCA) with chemical chaperone activity at the endoplasmic reticulum
- •Established pharmaceutical use for cholestasis and primary biliary cholangitis at 500-750 mg/day
- •Reduces ER stress and stabilizes misfolded proteins; the mechanistic basis for emerging ALS / retinal applications
- •Modest improvements in NAFLD markers and insulin sensitivity at 500-1,750 mg/day in small trials
- •Mitochondrial protection signal in animal models drives the longevity-supplement positioning
- •Generally well-tolerated; mild GI effects are the main dose-dependent issue
Side-by-side
| Attribute | Spermidine | TUDCA |
|---|---|---|
| Category | supplement | supplement |
| Also known as | spermidine trihydrochloride, wheat-germ-extract spermidine | tauroursodeoxycholic acid, taurine-conjugated UDCA |
| Half-life (hr) ↗ | 6 | 4 |
| Typical dose (mg) ↗ | 1.2 | 500 |
| Dosing frequency | daily, typically morning with food | daily, divided into 2 doses with food |
| Routes | oral | oral |
| Onset (hr) | 2 | 1 |
| Peak (hr) | 4 | 2 |
| Molecular weight | 145.25 | 499.7 |
| Molecular formula | C7H19N3 | C26H45NO6S |
| Mechanism | 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. | Bile-acid signaling via FXR/TGR5 receptors; chemical chaperone reducing ER stress and unfolded protein response; mitochondrial protection through reduced outer-membrane permeabilization. |
| Legal status | OTC dietary supplement (wheat-germ extract has GRAS status in US) | OTC dietary supplement (US); pharmaceutical in Italy and several Asian countries |
| WADA status | allowed | allowed |
| DEA / Rx | OTC supplement (not scheduled) | OTC supplement |
| Pregnancy | Insufficient data; not routinely recommended at supplemental doses | Insufficient data for supplement use; UDCA used in cholestasis of pregnancy |
| CAS | 124-20-9 | 14605-22-2 |
| PubChem CID | 1102 | 9848818 |
| Wikidata | Q411089 | Q418751 |
Safety profile
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)
TUDCA
Common side effects
- mild GI upset
- diarrhea (dose-dependent)
- constipation (rare)
- nausea
Contraindications
- complete biliary obstruction
- pregnancy / lactation (insufficient supplement-dose data)
- active GI disease without medical supervision
Interactions
- cyclosporine, oral contraceptives, fat-soluble vitamins: modest absorption changes via altered bile-acid pool(minor)
- phenylbutyrate: synergistic for ALS use (Relyvrio combination); consult clinician(moderate)
Which Should You Take?
TUDCA 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. Spermidine is the right call when one of the conditionals below applies.
- → If your priority is focus or working memory, pick Spermidine.
- → If your priority is liver function, pick TUDCA.
- → If your priority is mitochondrial function, pick TUDCA.
Default choice: TUDCA. Lower friction to source, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for Spermidine 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 Spermidine and TUDCA?
Spermidine and TUDCA 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, Spermidine or TUDCA?
Spermidine half-life is 6 hours; TUDCA half-life is 4 hours.
Can you stack Spermidine with TUDCA?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
Go deeper