Anabolic androgenic steroids are synthetic derivatives of testosterone, which is the primary male sex hormone. Anabolic androgenic steroids are used to enhance athletic performance and appearance. Adverse effects include those on the liver, serum lipids, psyche/behavior and reproductive system. Androstenedione is an anabolic androgenic steroid used to increase blood testosterone levels for the purposes of increasing strength, lean body mass and sexual performance. However, there is no research indicating that androstenedione, or its related compounds, significantly increases strength and/or lean body mass in humans by increasing testosterone levels. The long-term health effects of prolonged androstenedione supplementation are unknown. Dehydroepiandrosterone (DHEA) is a weak androgen also used to elevate testosterone levels, and is advertised as an anti-obesity and anti-aging supplement capable of improving libido, vitality and immunity levels. However, research demonstrates that DHEA supplementation does not increase serum testosterone concentrations or increase strength in men, and may acutely increase testosterone levels in women, thus producing a virilizing effect.