NAC (N-Acetylcysteine) vs TUDCA
Two supplements with genuine, specific medical pedigrees that get marketed as general 'liver support' and 'antioxidant' pills far beyond what they were proven for.
NAC (N-Acetylcysteine)
A cysteine/glutathione precursor that is genuinely strong for specific medical uses (acetaminophen-overdose antidote, some psychiatry) but weak as an everyday 'antioxidant/detox' pill.
Full NAC (N-Acetylcysteine) evidence reviewTUDCA
Tauroursodeoxycholic acid
Real bile-acid chaperone biology with genuine human trial engagement — it was the active component of AMX0035/Relyvrio, which showed a positive phase 2 signal in ALS before its confirmatory phase 3 failed and the drug was withdrawn. The liver/ER-stress mechanism is solid; the clinical outcome record is now a cautionary tale, not a green light.
Full TUDCA evidence reviewSide by side
| NAC (N-Acetylcysteine) | TUDCA | |
|---|---|---|
| Marketed for | Antioxidant, detox | Liver health, ER-stress reduction, neuroprotection |
| Evidence grade | Clinical data | Clinical data |
| Family | NAD⁺ & mitochondrial | mTOR & other |
| Key human source | Acetaminophen antidote, NEJM 2008 | AMX0035 phase 2/3 ALS trial, NEJM 2020 |
marks a row where the two differ. Evidence grades come from our evidence matrix, which grades each molecule on the human data for the use it is marketed for.
Our verdict
NAC's real strength is narrow and dramatic: it's the antidote for acetaminophen overdose, with genuine psychiatric evidence in some conditions, but weak as an everyday antioxidant. TUDCA's real strength is also narrow: real bile-acid chaperone biology, and it was the active component of a drug that showed a positive Phase 2 signal in ALS before its confirmatory Phase 3 failed and the drug was withdrawn. Both are legitimate molecules with real pedigrees stretched into 'daily liver detox' claims their trials don't support.
NAC (N-Acetylcysteine) fits if
A specific medical use (overdose antidote under supervision, or a psychiatric application discussed with a prescriber) is the actual goal, not general detox.
TUDCA fits if
Liver-specific or ER-stress biology is the interest — but know its highest-profile human outcome trial ultimately failed to confirm.