Viagra has been around for quite some time as a sexual aid for men. But there are dangers with use that make the product not suitable for use by some.

As such, many herbal alternatives have been released and marketed to take advantage of this shortfall -- but they, too, could cause problems according to new research.

If you're on common heart and blood-pressure drugs, taking one of these herbal-based sex pills could lead to a stroke or even death, according to the research. Why? Well, these products may just contain unregulated versions of the very pharmaceuticals they are supposed to replace. Therein lies the wrinkle -- reactions inside that body that can lead to serious health consequences.