Short answers, pulled from the story.
Amphetamine was first synthesized in 1887 in Germany by Romanian chemist Lazăr Edeleanu, who named it phenylisopropylamine. Its stimulant effects remained unknown until 1927, when Gordon Alles independently resynthesized it and reported its sympathomimetic properties.
Amphetamine is approved to treat attention deficit hyperactivity disorder (ADHD) and narcolepsy. In the form of lisdexamfetamine, it is also the only USFDA- and TGA-approved pharmacotherapy for binge eating disorder, as of July 2024.
Dextroamphetamine binds the dopamine transporter more strongly than levoamphetamine and produces roughly three to four times greater stimulation. Levoamphetamine has slightly stronger cardiovascular and peripheral effects. At normal urine pH, dextroamphetamine has a half-life of 9-11 hours, while levoamphetamine's half-life is 11-14 hours.
Addiction is unlikely to result from long-term medical use at therapeutic doses. Research from lifetime follow-up studies indicates that stimulant therapy beginning in childhood actually reduces the risk of developing a substance use disorder as an adult. Addiction is a serious risk only with heavy recreational use at doses far above the therapeutic range.
Current amphetamine brand names in the United States include Adderall, Adderall XR, Mydayis, Adzenys ER, Adzenys XR-ODT, Dyanavel XR, Evekeo, Dexedrine, Zenzedi, Vyvanse, and Xelstrym. Evekeo is the only product containing only racemic amphetamine, while Dexedrine and Zenzedi contain enantiopure dextroamphetamine sulfate.
At therapeutic doses, amphetamine improves muscle strength, acceleration, endurance, reaction time, and performance in anaerobic conditions. A 2015 systematic review and meta-analysis found that low doses produce modest but unambiguous improvements in working memory, long-term episodic memory, inhibitory control, and some aspects of attention in healthy adults. High doses above the therapeutic range can impair cognitive function and cause rapid muscle breakdown.