The History

Sildenafil was originally synthesized in the UK by the pharmaceutical company Pfizer in the mid-90s. The team of chemists in the Kent research facility had intended to synthesize a drug for the treatment of hypertension and angina pectoris, and their work led them to the compound UK-92,480.

However, the first phase of clinical trials carried out by the team revealed that sildenafil citrate had little effect on the patients' angina, but did cause erections in the men . After further research, it was decided that the substance would be marketed as a treatment for those suffering erectile dysfunction – and was the very first drug of its kind on the market.

The drug was patented in 1996, approved by the Food and Drug Administration two years later and went on sale in the United States in 1999.

Pfizer still owns the worldwide patents on sildenafil citrate, but these are due to expire in 2011-2013.

Important Facts

• It is of course advised to seek medical advice before beginning a course of Sildenafil. A medical professional is equipped to take into account the individual medical history and make informed decisions about the required dosage of the drug.


• Sildenafil is available in three dosages:
• 25mg,
• 50mg and
• 100mg.
Most medical professionals will recommend beginning treatment with a pill of 50mg dosage, and then, depending on the results, moving to either the stronger or weaker variety. Cutting the pills in two (to reduce strength) is not usually possible, as the coating of Sildenafil is very hard and extremely difficult to cut through.


• It is recommended that – to ensure the best results – the pill is taken between thirty minutes and four hours prior to sexual intercourse taking place.


• This drug works for 4 hours.