Adrafinil (CRL-40028, Olmifon) is a mild central nervous system stimulant used to relieve excessive sleepiness and inattention. It is also used to avoid fatigue by night workers or others who need to stay awake and alert for long periods of time. Adrafinil is a prodrug; it is primarily metabolized in to modafinil, resulting in nearly identical pharmacological effects. Unlike modafinil, however, it takes time for the metabolite to accumulate to active levels in the bloodstream. Effects usually are apparent within 45–60 minutes when taken orally on an empty stomach. Adrafinil was discovered in the late 1970s by scientists working with the French pharmaceutical company Group Lafon. First offered in France in 1986 as an experimental treatment for narcolepsy, Lafon later developed modafinil, the primary metabolite of adrafinil. Modafinil possesses greater selective alpha-1 adrenergic activity than adrafinil.