People buying medicines on the Internet are being warned they could be putting their lives at risk.
The warning comes after authorities confirmed they have seized large amounts of counterfeit medicines, including 10,000 tablets claiming to combat erectile dysfunction and 130,000 BZP tablets.
The discoveries were announced as part of an international effort to combat the illegal supply of medicines online.
The so-called Operation Pangea II was co-ordinated by Interpol and involved 24 countries, plus the World Health Organization, together with police and customs.
"Our primary goal in participating in this operation is to protect the public by removing counterfeit and illicit medicines from the market." Health Minister Michael McGimpsey said.
"We have recovered a range of different medicines that were being supplied illegally as part of my Department's ongoing strategy to combat counterfeit medicines through a sustained programme of communication, collaboration and regulation.
"The types of medicines seized in Northern Ireland over the last year include steroids, Benzylpiperazine (BZP), human growth hormones and medication for erectile dysfunction."
His department has conducted 20 investigations during the past 18 months into illegal importation and supply of unlicensed and counterfeit medicines.
The minister said: "When you purchase medicines from an illegal supplier online, you simply don't know what you are taking.
"The products may be stored in filthy conditions, the dosages can be too high or too low or may contain totally different ingredients to those stated.
"The products are usually designed to deceive the public that they are genuine."
© Press Association