Berlin  - People who purchase medicines on the internet should check the seller carefully because the risk of counterfeits is high, warned Manfred Schubert-Zsilavecz, president of the Frankfurt- based German Pharmaceutical Society (DPhG).

Speaking recently in Berlin, Schubert-Zsilavecz said there were ways to distinguish respectable internet pharmacies from shady ones. Web sites of the former will have a complete imprint as well as a telephone number for customer's inquiries, he noted.

Customers should also be wary of sellers who advertise very aggressively or who do not require a doctor's prescription for prescription medicines.

After a medicine purchased on the Internet has arrived, it should be examined closely, Schubert-Zsilavecz added. Are the tablets or capsules in the original packaging or did they come in a heap in a plastic bag? Do the tablets or the packaging look unusual?

"Counterfeit medicines pose a large health risk. At worst, incorrect active ingredients or toxic substances can lead to death," the DPhG president said.

Professional counterfeiters are hard to spot, however. "A well- made counterfeit can only be recognised in a laboratory," remarked Magdalene Linz, president of Germany's Federal Chamber of Pharmacists.

According to Schubert-Zsilavecz, internet sales of counterfeit medicines have risen in recent years. The World Health Organisation estimates that half of the medicines purchased online are counterfeit. It said they included not only lifestyle medicines for things like hair loss or excess weight, but also increasingly medicines for cardiovascular diseases and cancer. (dpa)