Two Viagra TV ads are making unsubstantiated claims about sexual desire and should be pulled out, the FDA told Pfizer Inc, the makers of Viagra. The claims relate to a return of sexual desire.

The ads do not mention side effects, says the FDA. The ads do not explain who should not be taking Viagra (Viagra is dangerous for some people). The ad does not explain what Viagra is for - erectile dysfunction (male impotence, difficulty in getting an erection).

What one of the ads does say, is that that guy you used to call ?wild thing' is back. This, says the FDA, implies that the guy has returned to a previous level of sexual desire and activity. Viagra helps many people get an erection, when aroused, but it does not raise sexual desire. The FDA, said in a letter to Pfizer, \"FDA is not aware of substantial evidence or substantial clinical experience demonstrating this benefit for patients who take Viagra.\"

The letter invited Pfizer to forward any evidence it may have to substantiate that claim. So far, Pfizer has made no comment.

The FDA told Pfizer to pull the ads immediately and respond to the letter by November 24th.

Erectile dysfunction drugs are battling for market share. These days, there are several drugs on the market. Among them are Cialis (Eli Lilly) and Levitra (GSK/Bayer).

If you are on certain prescription drugs (nitrates), Viagra can be dangerous for you as it can lower your blood pressure to dangerous levels. Viagra does have unpleasant side effects (affects some people), such as headaches, flushing and blurred vision.