It's an international crime business that endangers human lives and generates billions of dollars every year through the sale of tablets and powders.
Unlike drug smuggling, however, medicine counterfeiting is still not considered a criminal offence under the legal systems of a number of east European countries including Ukraine.
"We tell the police.
They open investigations and then just drop them.
It's not a crime," said an exasperated Anna Pilipenko, an inspector at a laboratory in Kiev that is part of a state network for testing thousands of pharmaceuticals.
But as this country of 47 million people draws closer to the West, officials are gradually getting to grips with the problem, tabling new laws and introducing increased checks.
Ukraine is still lagging in healthcare, with a life expectancy of 68 that is 10 years below the average in the neighbouring European Union, according to EU and World Bank figures.
So far in 2007, Pilipenko's lab has found three percent of pharmaceuticals checked to be counterfeits.
Usually the products are not toxic but contain far less of their active ingredient than required.
Pilipenko pointed to a shelf used for teaching purposes that contained dozens of medicine packages in pairs -- a genuine version and a seemingly indistinguishable fake one.
Looking more closely, the differences appeared.
One cure against stomach pains turned out to be vanilla powder and several remedies against allergies and influenza carried the wrong markings.
These medicines can be seized from chemists and hospitals as they constitute a health risk for Ukrainians, but at the moment their producers and importers cannot be prosecuted.
In addition there are numerous medicines sold at discount prices through Internet sites that have sprung up in Ukraine, meaning that the proportion of counterfeits could be higher.
The World Health Organisation (WHO) estimates that more than 20 percent of the market in ex-Soviet republics like Russia and Ukraine could be made up of fakes and warns that the trade is putting patients at risk.
"The counterfeit pharmaceutical problem is very strong in Ukraine," said John Anderson, head of the Britain-based Global Anti-Counterfeiting Network, who travels frequently to Ukraine.
"The pharmaceutical companies don't tell anyone.
They're desperate not to raise alarm over possible pharmaceutical fakes in case the market for their products drops like a stone," Anderson said.
Government checks, he added, are also "wildly open to corruption." But officials in this former Soviet republic have vowed to stamp out the fake medicine problem as part of a drive for Ukraine to join the World Trade Organisation (WTO).
Health authorities have established a network of 27 laboratories for testing and legislation making medicine counterfeiting a criminal offence is expected to be adopted by parliament later this year.
The medicine inspection service for Ukraine has issued five product recalls so far this year because of health risks and in an interview with AFP deputy chief inspector Vladislav Onishchenko rejected charges of corruption.
Industry representatives have welcomed such initiatives but say that in eastern Europe as a whole not enough effort is being made to root out counterfeiting.
"It's often difficult to get an investigation going," said Ashley How of the Pharmaceutical Security Institute, a US-based industry group that works with police and in-company investigators from major pharmaceutical firms.
Experts identify Russia, frequently ranked one of the world's biggest producers of counterfeit medicines, as among the main sources for the fakes in Ukraine and the EU.
As in Ukraine, Russian lawmakers are also discussing proposals to toughen penalties against medicine counterfeiting.
But the authorities have been criticised for poor enforcement of existing laws.
Last year, a company called Bryntsalov-A, which is owned by a member of Russia's parliament, was accused of counterfeiting and taken to court.
The company got off with a 1,500-dollar (1,100-euro) fine for improper storage.