Students say they are turning to a powerful prescription drug that is stocked by the Army to keep combat troops alert.

Modafinil, used to treat sleep disorders such as narcolepsy, appears to be overtaking the antihyperactivity medicine Ritalin as the “smart drug” of choice on university campuses.

Drug trials suggest that modafinil, which can be bought on the internet, is highly effective at enhancing short-term memory and enabling users to stay up for extended periods.

But experts say overuse can produce adverse side-effects. Some are also beginning to question why a performance-enhancing drug that is banned for athletes in the Olympics should be allowed for students in exams.

Paul Cooper, director of education at Leicester University, said that, although universities had been aware for some time that students were using drugs such as Ritalin and modafinil to get them through their exams, there had been no proper consideration of whether this constituted cheating.

“As a society we need to ask whether we are happy about people who have no impairments using these drugs to enhance their exam performance – we don’t allow it in sport, so why at university? Should we regard these drugs as a pharmaceutical version of the pocket calculator – something that students now rely on in exams as a matter of course? This is a debate that needs to happen.” Barbara Sahakian, Professor of Clinical Neuropsychology at Cambridge University, agreed that it was difficult to know where to draw the line. “We’ve done studies on modafinil. It’s very effective and it doesn’t have the same side-effects as Ritalin. I’ve been at meetings where I’ve been offered modafinil by colleagues to combat jet lag,” she said.

“This is one of the first drugs where it doesn’t seem to have abuse potential. It seems to be a good enhancing agent with minimal side-effects. The question is what do we do? Should we treat it like coffee?”

If the answer is yes, the next question facing universities may be this: should students be encouraged to take such drugs?

Students have used drugs to boost their study performance in the past. Caffeine and ginseng are traditional favourites. But recently the use of more powerful, restricted drugs, particularly Ritalin, has spread from campuses in the US.

At present the debate within British universities remains focused on the health risks faced by students taking prescription drugs. But students appear not to share these concerns. An undergraduate at Oxford told The Times that he was selling modafinil tablets to other students. “I bought the tablets on a Canadian website but they were produced in India,” he said. “I paid less than £1 per tablet and sold them on for £8 to £12 a hit. I made over £3,000 in less than two months. It got even more popular as finals approached.”He said that he would get up at 5am, take a tablet and then go back to sleep for an hour. “I’d get up and feel completely refreshed, and I could work all the way through until going to bed at 1am the next morning.”

A spokesman for Oxford University said that any student aware of drug dealing should report it to the police. Veronica King, head of welfare at the National Union of Students, said that such dealing may be a sign of the increasing pressures placed on today’s students.

Times Recommends

• DIY video helps the WI get to grips with sex
• Artists urge nation to save Titians
• Go home, Iraqi leader tells Britain