Comparison
Melatonin vs TUDCA
Side-by-side of Melatonin 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.
Melatonin
Melatonin as a sleep supplement: 0.3-1 mg matches physiological output, 3-10 mg is pharmacological. Shifts circadian phase, shortens sleep latency.
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
Melatonin
- •Shortens sleep onset latency by ~7 to 12 minutes at physiological 0.3 to 1 mg doses
- •Advances circadian phase when taken 30 to 60 minutes before target bedtime, useful for jet lag and shift work
- •Does not meaningfully increase total sleep time in healthy adults without circadian misalignment
- •Endogenous nighttime production is not suppressed by short-term exogenous supplementation
- •Higher doses (3 to 10 mg) raise plasma levels above physiological range and often increase morning grogginess
- •Effective for delayed sleep-wake phase disorder and reducing jet-lag severity in eastward travel
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 | Melatonin | TUDCA |
|---|---|---|
| Category | supplement | supplement |
| Also known as | N-acetyl-5-methoxytryptamine | tauroursodeoxycholic acid, taurine-conjugated UDCA |
| Half-life (hr) ↗ | 0.75 | 4 |
| Typical dose (mg) ↗ | 0.5 | 500 |
| Dosing frequency | daily, 30 to 60 minutes before target sleep time | daily, divided into 2 doses with food |
| Routes | oral, sublingual | oral |
| Onset (hr) | 0.5 | 1 |
| Peak (hr) | 1 | 2 |
| Molecular weight | 232.28 | 499.7 |
| Molecular formula | C13H16N2O2 | C26H45NO6S |
| Mechanism | Agonist at MT1 and MT2 receptors in the suprachiasmatic nucleus, signaling biological night and promoting sleep-onset gating plus circadian phase shifts. | 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 in US; prescription in UK, EU, Japan | OTC dietary supplement (US); pharmaceutical in Italy and several Asian countries |
| WADA status | allowed | allowed |
| DEA / Rx | OTC supplement in US; Rx in UK, EU, Japan, Australia | OTC supplement |
| Pregnancy | Insufficient data; not routinely recommended | Insufficient data for supplement use; UDCA used in cholestasis of pregnancy |
| CAS | 73-31-4 | 14605-22-2 |
| PubChem CID | 896 | 9848818 |
| Wikidata | Q179243 | Q418751 |
Safety profile
Melatonin
Common side effects
- vivid dreams
- morning grogginess (higher doses)
- headache
- dizziness
Contraindications
- autoimmune disease (theoretical)
- concurrent anticoagulant therapy without monitoring
Interactions
- fluvoxamine: CYP1A2 inhibition raises melatonin levels substantially(major)
- warfarin: possible increased bleeding risk(moderate)
- benzodiazepines and alcohol: additive sedation(moderate)
- antihypertensives: may alter blood pressure response(minor)
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. Melatonin is the right call when one of the conditionals below applies.
- → If your priority is sleep onset or sleep quality, pick Melatonin.
- → If your priority is circadian regulation, pick Melatonin.
- → If your priority is liver function, pick TUDCA.
- → If your priority is healthspan extension, pick TUDCA.
Edge case: Half-lives differ materially (Melatonin ~0.75 hr vs TUDCA ~4 hr). TUDCA reaches steady state faster; Melatonin is easier to dial in if tolerability is uncertain.
Default choice: TUDCA. Lower friction to source, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for Melatonin 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 Melatonin and TUDCA?
Melatonin 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, Melatonin or TUDCA?
Melatonin half-life is 0.75 hours; TUDCA half-life is 4 hours.
Can you stack Melatonin 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