Androstenedione

      Androstenedione is a type of hormone that is a direct precursor and metabolite of the hormone testosterone. Both converts back and forth to each other by action of the enzyme 17-beta hydroxysteroid dehydrogenase.

      Androstenedione is synthesized into testosterone, it's supplementation likely increases testosterone production and the androgenic properties associated with testosterone that are desired by bodybuilders such as increased energy, strength, muscle development and decreased recovery time from workouts.

      German studies have shown up to a 237% increase in free testosterone levels after a 100 mg dose of androstenedione. Free testosterone levels may begin rising in as little as 15 minutes after taking androstenedione on an empty stomach.

Here is the conversion process in the production of testosterone:

Cholesterol=>Pregnenolone=>DHEA=>Androstenedione=>Testosterone

      Enzymes are involved at each step of the process and may be a limiting factor in this conversions.Androstenedione is most likely better at converting to testosterone than DHEA is. For one, DHEA is two steps away from testosterone. This means that there are more enzymes involved in the process. Androstenedione is only one step away.

      Optimal testosterone levels keep healthy red blood cells, rapid protein production, and a balanced immune system. It increased energy, greater sense of overall well-being, and enhanced recovery and repair after exercise.

      In 100 mg doses, Androstenedione does not appear to have a negative effect on natural production of luteinizing hormone (LH). This is important because a reduction in luteinizing hormone would signal that natural testosterone production may be diminished. It is unknown whether larger doses of androstenedione will affect luteinizing hormone production.