RICHMOND midfielder Ben Cousins has requested the AFL test him to confirm there were no illicit drugs involved in his admission to hospital on Monday.

The 32-year-old was released from Melbourne's Epworth Hospital on Tuesday afternoon after suffering a severe reaction to a prescribed sleeping tablet.

While Cousins' playing future remains uncertain, the Tigers confirmed his condition had improved significantly overnight.

"The most important thing over the past 24 hours has been Ben's health and the club is pleased he is expected to make a full recovery," Richmond general manager of football Craig Cameron said in a statement released by the club.

"No decision has been made on his immediate playing future."

Cousins' hospitalisation will encourage Richmond to reiterate the importance of following directions on prescribed medication.

"Players are continually counselled on the correct use of prescribed medication and the club will continue to be vigilant to ensure players are well informed," Cameron said.

It was also reported that Cousins had taken caffeine tablets before Richmond's win over the Sydney Swans on Sunday.

An AFL spokesman said that the League adhered to the WADA code, under which caffeine was not a banned substance.

"The health and welfare of players is the primary concern of AFL club medicos. No player should take any form of tablet, supplement or medication etcetera without the guidance of a medical practitioner," he said.

"The same can be said about prescription sleeping tablets. They should only ever be taken in accordance with doctor's advice as recommended dosage levels are in place to ensure against the potential for any harmful side effects."

Cousins, a former drug addict, avoided a huge media pack when he left Epworth Hospital around lunchtime on Tuesday.

He was initially hospitalised after his girlfriend was unable to wake him on Monday morning.

Sedated and moved to intensive care on Monday afternoon, Cousins' condition had improved enough by Tuesday morning for medical staff to release him.

Cousins played 238 games for West Coast but was sacked by the club in 2007 after his arrest on drugs charges, which were later dropped.

The Brownlow Medallist and premiership player spent 2008 out of the game after being deregistered by the AFL.

He was recruited by the Tigers with the last pick in the 2009 NAB AFL Pre-Season Draft, and despite battling injury, has played 25 matches for them.