About Estradiol
Estradiol (E2) is the most potent form of estrogen and the dominant female sex hormone, though men require adequate estradiol too for bone density, cardiovascular protection, sexual function, and brain health. In women, estradiol fluctuates throughout the menstrual cycle and declines dramatically at menopause — driving symptoms like hot flashes, insomnia, and accelerated bone loss. In men, both very low and very high estradiol cause symptoms, with excess estradiol typically linked to high body fat or aromatase overactivity.