Mitochondrial
Dysfunction
Mitochondria are your cells’ power plants. By age 70, OxPhos efficiency drops ~30%, NAD+ falls ~50%, and mitochondrial ROS leaks accelerate damage across every hallmark of aging. Fixing this is foundational.
The Mechanism
The energy crisis — and why it cascades
Mitochondrial decline is driven by three converging failures. First, mtDNA mutation accumulation: mitochondrial DNA (37 genes) has no histone protection and minimal repair capacity. mtDNA mutation rate is 10–17× higher than nuclear DNA. By age 70, some cell types have mutation rates >20% in respiratory chain genes.
Second, NAD+ depletion: NAD+ is both the electron carrier feeding Complex I and the substrate for SIRT3 — the deacetylase that activates mitochondrial metabolic enzymes. As NAD+ drops, Complex I stalls, the ETC backs up, and electrons leak to oxygen, forming superoxide instead of being efficiently coupled to ATP synthesis.
Third, impaired mitophagy: damaged mitochondria are normally cleared by the PINK1/Parkin pathway — a quality control system that tags depolarized mitochondria for autophagy. With age, PINK1 expression declines and Parkin activity decreases, allowing damaged mitochondria to accumulate and continue secreting ROS and pro-apoptotic factors.
The consequence is mitohormesis disruption: mild mitochondrial stress is normally beneficial (hormesis), triggering adaptive responses via PGC-1α, AMPK, and NRF2. Severe, chronic mitochondrial stress overwhelms these pathways and drives the inflammatory phenotype, mtDNA release into cytoplasm (activating cGAS-STING), and systemic age acceleration.
Key Molecular Axes
NAD+ → SIRT3
Activates OxPhos enzymes, IDH2, SOD2; declined by ~50% by age 60
AMPK → PGC-1α
Drives mitochondrial biogenesis; suppressed by mTORC1 hyperactivation in aging
PINK1 / Parkin
Mitophagy quality control; removes depolarized mitochondria; declines with age
Monitoring
Biomarkers that track mitochondrial health
Evidence-Graded Interventions
Mitochondrial interventions with human evidence
Tier A = multiple human RCTs. Tier B = at least one human trial + mechanistic data. Listed in order of evidence strength.
GlyNAC (Glycine + NAC)
Tier AThree RCTs (Mayo Clinic) demonstrate GlyNAC directly restores mitochondrial function in older adults: it rebuilds glutathione, reduces mitochondrial ROS, improves OxPhos efficiency, and increases mitochondrial biogenesis markers (PGC-1α). Only compound with multiple human RCTs specifically measuring mitochondrial function restoration.
Urolithin A
Tier AUrolithin A is the most clinically-validated mitophagy inducer. It activates PINK1/Parkin pathway — the mitochondrial quality control system that tags damaged mitochondria for autophagy. The 2022 Amazentis RCT (PMID: 35922106) showed improved muscle endurance and mitochondrial gene expression in older adults at 4 months.
NMN / NR (NAD+ precursors)
Tier ANAD+ is the electron carrier that feeds Complex I of the electron transport chain. As NAD+ drops ~50% by age 60, mitochondrial respiration efficiency collapses. NMN/NR restore NAD+, improve OxPhos coupling efficiency, reduce mitochondrial ROS leak, and activate SIRT1/SIRT3 — which deacetylate and activate mitochondrial enzymes.
CoQ10 (Ubiquinol form)
Tier BCoQ10 is the mobile electron carrier between Complex I/II and Complex III of the ETC. Plasma CoQ10 declines ~40% between ages 20 and 80 — and statin use accelerates depletion another 20–40%. Ubiquinol (reduced form) shows superior bioavailability. The Q-SYMBIO trial (PMID: 25282031) demonstrated 43% reduction in major cardiovascular events.
Alpha-Lipoic Acid (R-ALA)
Tier BR-ALA is a cofactor for pyruvate dehydrogenase and α-ketoglutarate dehydrogenase — both mitochondrial enzyme complexes that feed the TCA cycle. It also recycles CoQ10, Vitamin C, and glutathione. As a mitochondrial antioxidant, R-ALA is 10× more potent than α-tocopherol at the inner mitochondrial membrane.
Build a mitochondrial protocol.
The Stack Architect maps your energy and mitochondrial goals to evidence-graded compounds and shows which hallmarks each compound targets.