Androstenedione (also known as andro) and dehydroepiandrosterone (also known as DHEA) are prohormones or "natural steroids" that can be broken down into testosterone. When researchers studied these prohormones in adult athletes, DHEA and andro did not increase muscle size, improve strength or enhance performance.

The side effects of these "natural" steroid supplements like DHEA and andro aren't well known. But experts believe that, when taken in large doses, they cause effects similar to stronger anabolic steroids.

Andro and DHEA can cause hormone imbalances in people who use them. Both may have the same effects as taking anabolic steroids and may lead to dangerous side effects like testicular cancer, infertility, stroke, and an increased risk of heart disease. As with anabolic steroids, teens who use andro while they are still growing may not reach their full adult height.

Natural steroid supplements can also cause breast development and shrinking of testicles in guys.