Nearly 250 packages of medications that were investigated when they crossed the country's borders, have prompted Medsafe to warn about the dangers of ordering medicine online.
Prescription medicines purchased on the internet were risky because quality, safety and effectiveness could not be guaranteed, Medsafe manager compliance management Derek Fitzgerald said.
Prescription medicines were potent substances and as such should only be used following a consultation with a doctor, he said.
New Zealand has recently been involved in a week-long Interpol-led operation, Operation Pangea VII, which was aimed at detecting the international illegal trade in medicines.
As a result of the operation, 248 packages were held requiring further investigation, 50 less than the number investigated last year, Mr Fitzgerald said. These parcels originated from 32 different countries around the world and were stopped because they contained prescription medicines, weren't labelled or were known to contain undeclared or hidden ingredients.
The most common sources of these products were India (90), Switzerland (29) and Great Britain (18).
"Medsafe strongly encourages anyone intending to buy prescription medicines via the internet to consult their doctor who can advise on potential side effects, interactions with other medicines and appropriate dosage," Mr Fitzgerald said.
"Consumers who buy online run the risk of purchasing medicines that are inappropriate for them or unknowingly purchasing medicines that are counterfeit, of poor quality or contain dangerous ingredients."
Prescription medicines were referred to Medsafe by Customs to ensure compliance with New Zealand law.
Most prescription medicines Medsafe detained were held until the importer provided a valid doctor's prescription - if this did not occur they were destroyed.
By the numbers:
• Most medicines were for the treatment of erectile dysfunction - 5234 individual tablets
• Medicines for insomnia, endocrine disorders and heart disease / cholesterol were the next most prevalent
• Two parcels contained a counterfeit or fake product for the treatment of erectile dysfunction