Modafinil is a prescription medication classified as a wakefulness-promoting agent and is commonly used to treat excessive sleepiness caused by narcolepsy, obstructive sleep apnea, and shift work sleep disorder. While its exact mechanism of action remains uncertain, research suggests it works by inhibiting the dopamine transporter, thereby increasing extracellular dopamine levels and indirectly activating noradrenaline pathways and other neurotransmitter systems in the brain. Modafinil also enhances brain signaling in the orexin, histamine, and glutamate pathways and decreases GABA activity, leading to improved alertness and cognitive performance without the significant euphoric effects typically associated with other stimulants.