Hormone Booster contains 3,4-divanillyltetrahydrofuran, an isolated plant extract from Urtica dioica. SHBG binds to, and deactivates, testosterone in men, and estrogen and testosterone in women (SHBG preferentially blocks testosterone rather than estrogen). By inhibiting SHBG, Hormone Booster increases the levels of active unbound testosterone and estrogen. Testosterone improves muscle tone, fat loss, exercise performance, libido, mental function, energy and mood in men and women. Testosterone also helps prevent andropause in men, as well as improves cardiovascular, immune system and brain health in men and women. Estrogen helps prevent menopausal symptoms and brittle bones in women.