In 2026, modafinil remains the quintessential eugeroic, a class of medications specifically engineered to promote a state of "clean" wakefulness without the intense physical strain often associated with traditional stimulants. Originally developed to treat sleep disorders like narcolepsy and obstructive sleep apnea, it works by precisely modulating neurotransmitters in the brain's sleep-regulation centers—most notably increasing dopamine and stimulating orexin and histamine pathways