Egg maturation is unusually energy-hungry, and that energy comes from mitochondria. CoQ10 is a cofactor in mitochondrial energy production and an antioxidant, and its natural levels decline with age.
Trials in people undergoing IVF, particularly those over 35 or with diminished ovarian reserve, have reported improvements in retrieved oocyte numbers and fertilisation rates. Evidence in unassisted conception is thinner. In men, CoQ10 has been associated with improved sperm motility and concentration in several trials.
Typical study doses range from 200 to 600 mg daily, often taken with a fat-containing meal for absorption.