Viagra users are being urged to exercise caution after customs officers seized more than 230 fake sexual performance pills from six local pharmacies.
During Friday's operation, 236 counterfeit Viagra and Cialis tablets were confiscated from six of 11 pharmacies raided.
Seven men and one woman were arrested and have been released on bail. No charges have yet been laid.
'Samples of the fake drugs have been sent to the government laboratory ... the report is expected to be completed in two months,' said customs official Chiu Yuk-hung.
Mr Chiu said the packaging of the fake drugs usually had blurred or darker printing.
'It is quite easy to spot, but most customers feel embarrassed when buying such pills. They usually just pay the money, grab the pills and leave. They do not inspect the markings carefully,' he said.