The sting was part of an Interpol-led operation called Pangea VIII which aimed to disrupt criminal networks trading in illicit, counterfeit and poor quality medicines through working with international and national enforcement bodies, and internet and payment system providers.
The parcels investigated came from 29 different countries. More than 100 were from India, while 24 were from the United States, and 20 were from China.
Derek Fitzgerald, Medsafe manager of compliance management, said medicines purchased online were risky because quality, safety and effectiveness weren't guaranteed.
"Consumers considering buying any type of medicine over the internet should be aware that, even though a website may appear to be legitimate, appear to be established in a well-regulated country, and appears to be offering well-known medicines, these impressions may not be true," he said.
Medsafe encouraged anyone intending to buy prescription medicines online to consult their doctor who could advise on potential side effects, interactions with other medicines and appropriate dosage, he said.
"Prescription medicines are potent substances and as such should only be used following a consultation with a doctor."
Most prescription medicines Medsafe detained were held until the person importing them provided a valid doctor's prescription, he said. If this didn't occur they were destroyed.