That plant is Eurycoma longifolia, and it grows in South-East Asia. Jack, which is also known as "Malaysian ginseng" or Tongkat Ali, is used to keep people from getting sick, fight stress, and make them stronger. Some people also think that the chemicals in the plant's roots can make rats more sexually interested and increase their testosterone levels. Because of this, Tongkat Ali powder might work as a supplement to help treat hypogonadism and LOH symptoms. (Source)