Long jack or Tongkat Ali as it is more commonly known has been studied for many uses, the affects of which seem very reliable through multiple studies, and many years of use. German Pharma Tongkat Ali is standardized for 10% Eurycomanone, a powerful Quassinoid (extracted compounds derived from plants). Long jack comes from the name 'long lasting' which certainly seems to be a benefit of using Tongkat Ali!
To get the benefits from Tongkat Ali a longer 8-12 week cycle can be undertaken, truth be told this can be run year-round, but we feel it is best kept to cycles of the above.