The health ministry forcibly shut down 74 websites from April to September that sold bogus pharmaceutical products, it has been learned.
As some counterfeit drugs can have life-threatening effects, the Health, Labor and Welfare Ministry intends to strengthen its oversight of such sites.
The ministry started monitoring relevant sites in April to prevent online sales of fake pharmaceutical items, outsourcing the task to a US company.
Under the current surveillance system, site operators are asked to take down the sites if they handle apparently counterfeit pharmaceutical products, including items with inadequate volumes of ingredients, as well as unapproved drugs.
Seventy-four sites that did not comply with the ministry's call were shut down with cooperation from Internet providers. Before April, the ministry had merely called on such operators to close their sites.
Many of the 74 sites had offered drugs for conditions like erectile dysfunction and sleep disorders.
The Pharmaceutical Affairs Law prohibits advertising the effects and brand names of pharmaceutical products that are not authorised by the government. Listing unauthorized drugs for sale on a website is regarded as advertisement under the law.
As bogus drugs have not received government approval, the ministry has deemed that the operation of sites that sell them is a violation of the law.
About 50 per cent of three pharmaceutical products for erectile dysfunction sold online were fake, according to a survey conducted from 2008 to 2009 by Pfizer Japan Inc. and three other firms.
One of the products did not include any active ingredients for the symptoms, while another contained 50 per cent more of such substances than approved drugs. Taking active ingredients beyond the approved limits can result in such side effects as headaches and nausea.
In April 2011, a man in Nara Prefecture was found to have suffered from impaired consciousness after using a bogus drug for erectile dysfunction.
Fake drugs available in Japan are believed to be produced mainly in China and other Asian countries. The number of drug imports suspended by customs surged to 736 in 2013, about 60 per cent more than in the previous year. In the first half of this year alone, the figure reached 610.
Sales of such drugs are said to have become a financial resource for crime syndicates.
The ministry is considering increasing its manpower in the area and asking the commissioned US company to assign more employees to monitor drug-selling sites.