PQQ (Pyrroloquinoline Quinone) vs TUDCA (Tauroursodeoxycholic Acid)

Mechanism

PQQ activates PGC-1alpha via CREB phosphorylation, directly stimulating mitochondrial biogenesis — the formation of new mitochondria. It acts as a redox cycling agent capable of thousands of catalytic oxidation-reduction cycles (compared to ~4 for vitamin C), providing exceptional antioxidant capacity. PQQ also modulates NMDA receptor signaling and promotes nerve growth factor (NGF) synthesis, supporting neuronal health and cognitive function.

Standard Dosing

10-20mg daily

Timing

With breakfast. Can combine in same meal with CoQ10.

Cycle Duration

ongoing

Side Effects

• Rare: headache
• Mild GI discomfort at higher doses
• Insomnia if taken late

Contraindications

• Pregnancy/lactation (insufficient safety data)

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Mechanism

TUDCA is a water-soluble bile acid conjugate (taurine + ursodeoxycholic acid) with potent hepatoprotective and cytoprotective properties. It inhibits the mitochondrial pathway of apoptosis by preventing BAX translocation to mitochondria and cytochrome c release. TUDCA reduces endoplasmic reticulum (ER) stress by acting as a chemical chaperone, assisting protein folding and reducing the unfolded protein response (UPR). It protects hepatocytes by stabilizing cell membranes, displacing toxic hydrophobic bile acids (chenodeoxycholic, lithocholic) from biliary epithelium, and promoting choleresis (bile flow). Additionally, it has neuroprotective effects via reduction of ER stress in neurons and modulation of the TGR5 bile acid receptor.

Standard Dosing

250-500mg daily

Timing

With meals for liver support. Some protocols recommend before meals to prime bile flow.

Cycle Duration

Cycle 4-8 weeks for liver support; ongoing at low dose for chronic liver conditions under supervision

Side Effects

• Diarrhea (dose-dependent)
• GI discomfort
• Flatulence
• Rare: calcification of gallstones

Contraindications

• Complete biliary obstruction (cannot reach bile ducts if obstruction is complete)
• Calcified gallstones (UDCA/TUDCA dissolve cholesterol stones, not calcified)
• Acute cholangitis
• Complete biliary obstruction
• Gallstones (may mobilize stones)

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