The true extent of counterfeiting is not known since no global study has been carried out. However, it is known that any kind of product can be counterfeited.
Counterfeit drugs can be found worldwide, the problem is increasing
and more frequent in developing countries.
The World Health Organization (WHO) estimates that while the
incidence of counterfeit drugs is less than 1% in developed countries,
a much higher percentage of the medicines in some developing countries
may be counterfeit. (See World Health Organization, “Medicines:
counterfeit medicines,” Fact sheet No 275 (Jan. 2010).