Methamphetamine
"I barely had enough time in the day to meet the obligations of my job until I began taking methamphetamine. It really energized me to focus on the task at hand and nothing else. Shortly after I began taking Methamphetamine I received two promotions at work and was given an additional supervisory role.  As an added benefit it curbed my appetite allowing me to work through lunch and in some cases even dinner without taking a break. Also there is almost no physical side effect, unlike Vyvanse and Amphetamine Salts made my body and head ache as well as gave me a craving to chain smoke. 

The only downside is the availability at the local chemist, it seems the refills can only be handled through a tribal doctor or local shaman."