At around 5.40am yesterday, officers based in Wigan and Leigh executed a warrant at a gym on Lowe Mill Lane.
The raid, which followed an investigation into drug supply, resulted in two men aged 23 and 37 being arrested.
They have been released under investigation while enquiries continue.
Police Sergeant Adam Wall from GMP’s Wigan and Leigh District Tasking Team, said: “While I appreciate this may appear to be an unusual case, I cannot stress how harmful steroids can be when they are in the wrong hands.
“We need to put a stop to this and will continue to take positive action to disrupt those who profit from the illicit supply of all types of drugs including steroids.
“We can only progress our investigations with your help so I’d like to take this opportunity to thank people who have contacted us with information and hope yesterday’s warrant serves as a message that we do take all reports seriously and where possible, will act on them.”