Provigil is a powerful eugeroic, or wakefulness-promoting agent, primarily prescribed to treat excessive daytime sleepiness associated with narcolepsy, obstructive sleep apnea, and shift work sleep disorder. Its primary benefit is the ability to sharpen cognitive alertness and sustain wakefulness without the intense "jittery" rush often linked to traditional stimulants. However, users should be aware of potential side effects such as persistent headaches, nausea, anxiety, and insomnia, particularly if taken too late in the day. More serious but rare risks include severe skin rashes (like Stevens-Johnson Syndrome) and heart palpitations, which require immediate medical attention. Because Provigil is a Schedule IV controlled substance, the most important precaution is to ensure you have a valid prescription; taking it off-label or without supervision can lead to dependency or dangerous drug interactions.