The Difference Between Nuvigil & Modafinil

Updated July 19, 2017

Provigil (Modafinil) and Nuvigil (Armodafinil) are both "wakefulness promoting" drugs, approved by the FDA for the treatment of excessive sleepiness. These two drugs contain slightly different versions of the same chemical and differ little in their effects.


Both drugs were developed by Cephalon Inc. Provigil was approved by the FDA in 1998, and Nuvigil in 2007.


Both drugs are stimulants used to treat excessive sleepiness (ES) resulting from obstructive sleep apnoea, shift work sleep disorder or narcolepsy. The manufacturer states specifically that the drugs are not approved for the treatment of the underlying issue causing ES.

Chemical Difference

Provigil is a racemic drug, meaning it contains a mixture of two different versions of the same molecule, which each have a slightly different effect. Nuvigil contains only one version of the molecule. This means that 50 per cent of the contents of a Provigil pill is actually Nuvigil.

Effects Common to Both

Provigil and Nuvigil are stimulant medications, with arousal effects similar to amphetamines. While it is known that both drugs affect several different neurotransmitters, the exact mechanism by which they induce wakefulness is not understood.

Differences in Effect

According to the manufacturer, the primary difference between Provigil and Nuvigil is that Nuvigil has a longer half-life, meaning it remains in the blood longer. The actual difference in half-life between the two drugs is not specified. No other differences are noted.


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About the Author

Tony Rogers has written articles for on diverse topics, from building mouse-traps to drug pharmacology. He has worked as an AutoCAD technician and instructor for eight years. Rogers is studying electrical engineering at Colorado State University.