UK Defence chiefs spent £50,000 over seven years buying medication dubbed the "smart drug" designed to keep military personnel awake for days, reports the Daily Star.
Following a Freedom of Information request, the MoD revealed that it had ordered a total of almost 10,000 tablets of Modafinil, sold under the brand name Provigil, in the last seven years.
For years the military has been exploring new methods to safely combat sleep deprivation and to prevent the associated degradation of performance.
A large part of battle fatigue is due to sleep deprivation, as when the military is on the move, almost everybody is required to perform mission-critical tasks way after they should be asleep.
It is widely understood that the nootropic, normally prescribed to treat narcolepsy, is being used as a stimulant by armies across the world, according to reports.
Special forces personnel and pilots are among those thought to use the medication on long duration missions.
The drug, touted as non-addictive, is also used by some students to help them concentrate while studying to meet essay and exam deadlines.
Modafinil is commonly prescribed by doctors for patients who suffer from sleeping disorders.
Reports also suggest that the medication has been used by athletes to improve performance in training.
Modafinil was developed in the 1970s by a French professor of experimental medicine to treat narcolepsy and other sleep disorders.
After clinical trials in France, the US Food and Drug Administration (FDA) okayed modafinil as a treatment for narcolepsy in 1998.
In 1999, the Drug Enforcement Administration (DEA) classified modafinil as a Schedule IV substance.