Viagra
Viagra, trade name of the first oral drug for male impotence, introduced by the pharmaceutical company Pfizer, Inc., in 1998. Also known by the chemical name sildenafil citrate, it is one of a category of drugs known as phosphodiesterase-5 inhibitors. See also PDE-5 inhibitor.
This article was most recently revised and updated by Amy Tikkanen.
Citation Information
Article Title:
Viagra
Website Name:
Encyclopaedia Britannica
Publisher:
Encyclopaedia Britannica, Inc.
Date Published:
26 September 2026
Access Date:
November 13, 2026