Viagra can affect men's fertility: Study

Here's bad news for all those young men who like popping Viagra pills to boost their bedroom performance -- the anti-impotence drug can damage your ability to father a child.

Researchers at the Queen's University in Belfast have found that Viagra harms fertility, particularly in young people who use the drug recreationally, and it could also impair their ability to have families.

"Viagra has become a widely used recreational drug. It is mixed with cocaine, for example, and is sold in clubs. Our work leaves open the possibility that there could be a cumulative effect from taking Viagra, however, which could pose serious fertility problems in later life," The Observer newspaper quoted lead researcher Dr David Glenn as saying.

In fact, the researchers came to the conclusion after carrying out two sets of experiments.

The first involved taking sperm samples from volunteers and then bathing them in weak solutions of Viagra. The aim was to produce a Viagra level equivalent to that found in the blood of a man who had taken a single 100-mg pill.

The researchers then compared the behaviour of the treated sperm with standard samples and found the drug had two principal effects.

It made sperm more active but also it damaged its acrosome, a cap-like structure that contains enzymes that break down the membrane surrounding a woman's egg and allows sperm to fertilise it.

"Essentially the acrosome breaks open too early in sperm that has been exposed to Viagra. The sperm cannot get into the egg and so it is not fertilised," Dr Glenn said.

His team carried out similar experiments on animals and found that sperm from mice that had been given Viagra produced 40 per cent fewer embryos than those on control pills. However, they found no evidence that baby mice produced by male mice on Viagra had been damaged in any way.

Moreover, according to the researchers, fertility clinics, which prescribe Viagra to help men produce sperm for IVF treatments, could actually be preventing some couples from conceiving.

"Couples going to clinics already have fertility problems. Viagra may simply be making those worse," Dr Glenn said.