There is no proof but, in 2008's Giro D'Italia, cyclist Andrea Moletta was suspended after syringes hidden in toothpaste tubes were found, along with 82 Viagra pills.
Victor Conte, who operated the infamous Balco laboratory which doped US athletes including Marion Jones, said when asked about Team Sky: "I used to give my athletes Viagra back in the day. We used to call it Vitamin V."
It just goes to show how some in sport will stop at nothing to succeed. Viagra at least has the handy benefit of curing impotence - a well-known side-effect of steroids. In 2012, NFL player Brandon Marshall said he'd heard some "crazy stories" of players using Viagra to improve on-field performance.
Never mind Viagra, Wada have their hands full considering a blanket ban on the drug used by Wiggins before his 2012 Tour de France win - the same one Lance Armstrong tested positive for at the 1999 Tour de France; explained away at the time by a post-dated medical note.
Wada have said the system of therapeutic use exemptions (TUEs) allowed athletes to use powerful steroids out of, and during, competition - but was open to abuse. You think?
While TUEs are legitimately used by some athletes for reasons approved by Wada, Wiggins came under attack after Russian hackers plundered confidential UK Anti-Doping files - retribution for Russia's ban from the 2016 Rio Olympics for systemic doping.
The Fancy Bears hackers revealed Wiggins was given three TUEs for triamcinolone injections before the 2011 and 2012 Tours, as well as the 2013 Giro d'Italia. Wiggins has claimed they were for a pollen allergy but triamcinolone - also known as Kenacort - can rapidly reduce an athlete's weight while maintaining power.
Another British cyclist, David Millar, banned in 2004 for doping offences, claimed that if he took Kenacort, he'd lose up to 2kg in a week and would feel stronger.
Wiggins has also denied a controversial Belgian doctor had any involvement in the decision to apply for the TUEs.
It's all rather distasteful and Viagra just seems to be the latest effort to stiffen cyclists', er, resolve to keep cheating.
It seems sad that Britain, the home of fair play in sport a few ice ages ago, should be so afflicted. A stiff upper lip is obviously needed in a country where, in the bad old days, sexual mores were so repressed, that even the men tended to lie back and think of England.
But when it comes to TUEs, there is an inescapable conclusion: athletes and their doctors seem clever at sidestepping the intent of the TUEs (designed so legitimate athletes do not have to miss competition because of medical ailments).
Maybe it is time TUEs were scrapped altogether. The concept, after all, that it is permissible to use banned substances if you're not well, is ultimately flawed. Maybe athletes have to get used to the idea that if they can't compete without a banned substance, they can't compete.
Don't like it? Stiff ...