It enhances sleep deprivation. A 100mg dose on 36 hours no sleep will likely reveal the shadow people, a 50 mg dose on 48 hours no sleep will very likely reveal the shadow people, a 25 mg on 72 hours no sleep will almost definitely reveal the shadow people.

You do not want to meet the shadow people. Not because they are exceptionally creepy, but because it probably means some amount of brain damage, and they will never completely go away after.