Viagra’s UK patent expires

Published: 21 June 2013
By: Peter Prowse

Viagra, used by millions of men to treat erectile dysfunction, lost its patent in the UK on 21 June. This means that rival manufacturers will legally be able to produce the drug under its generic name, sildenafil.


 “This is a great example of the patent system working as should,“ said Dr Gordon Wright, a spokesman for the Chartered Institute of Patent Attorneys. “Pfizer, the company that discovered and has been marketing Viagra, has had 15 years to make a return on its investment. It now loses its exclusive position and from today, doctors will be able prescribe the active ingredient, sildenafil, made by other drug companies. But Viagra is available only from Pfizer, the trade mark owner.”


Viagra was launched in 1998. Since then, Pfizer has produced billions of Viagra pills: in the UK alone, 2.3 million men were prescribed the drug last year. 

The drug was invented in the late 1980s, although its use in the treatment of male erectile dysfunction was not identified until 1993. A patent based on this new therapeutic use was filed a year later, and although granted by the European Patent Office in 1999, the patent was revoked by the UK High Court who found the new use ‘obvious’. This did not affect the validity of the earlier substance patent for sildenafil. But the expiry of the patent (and its associated SPC) today means the Pfizer no longer has its exclusive position in the active substance.

The pharmaceutical company also has other patents on sildenafil as a treatment for pulmonary arterial hypertension.  That medication is marketed under a different brand name and the patents still have some time to go before they expire.