Australian soldiers sent home for steroid use.

Three soldiers have been sent home from Afghanistan after being caught using anabolic steroids. Earlier this year, four elite special forces soldiers were also found to be using steroids.

One defence commentator says the problem is worrying because although soldiers know they can be routinely tested for drug use, they are persisting with their risky behaviour.

The Defence Department says of the three men recently caught with steroids, one has been discharged and the other two are in the process of being sacked from the Army.

The executive director of the Australia Defence Association, Neil James, says the low number of cases indicate this is not a major issue for the Army.

"We don't see this as being a widespread problem at all, considering the number of people that serve in Afghanistan each year, that's about one in 600, which is a remarkably low percentage," he said.

Drug testing soldiers has moved from random to routine in the past couple of years, and Mr James says it is surprising troops thought they could avoid detection.

"Well the only thing that's a little bit disquieting about this is now the testing of the troops overseas is near 100 per cent, you wonder how anyone thought they could get away with it," he said.

"But steroid use tends to be a sign of boredom and it tends to be a little bit of a competitive thing among young, fit Australians.

"So if you've got the problem in the wider society then you're eventually going to have it in your military. But how they thought they could get away with it is a bit puzzling."

Commentators argue taking steroids does not provide a physical edge in combat, and Mr James says, if anything, the cases have uncovered a vain streak among Defence personnel.

"What you need in combat is physical fitness and endurance fitness and steroids have more to do with muscle tone," he said.

It has been well documented that steroids can sometimes carry the side effect of what is known as 'roid rage'.

But Mr James says he doubts the soldiers would be suffering from those side effects.

"Well you would, wouldn't you, but steroid use that produces rage is generally severe steroid use and without knowing what the random or the 100 per cent testing has uncovered, I suspect that is probably hasn't been major overuse, it's just been to a lesser level," he said.

"So I don't really think the rage would have been too much of a problem and there's lots of ways that would have been uncovered anyway, just in the way that soldiers look after each other and their general behaviour."

Mr James says drug use tends to be more common in general units and not among special forces or commandos.

He says they are busier and more disciplined than an average soldier.