Researchers at a British biotech firm have devised a "Viagra condom" for men who can't maintain an erection while wearing protection, reports Tommy Stubbington at The Wall Street Journal. The new condom, currently known only as CSD500, will include a liquid gel that helps send blood to the penis, resulting in a firmer, longer-lasting erection. This innovation could have a big impact on the prophylactic industry, in which "innovation is rare and patent-protected inventions are infrequent." Here, a brief guide:

How does it work?

The condom's tip is laced with Zanifil, a liquid gel that increases blood flow to the penis. In European clinical trials, subjects reported more enduring erections, as well as an increase in penis size.

When might this be on U.S. shelves?

In Europe, the condom has been licensed to British consumer giant Reckitt Benckiser, which will manufacture it through the well-known Durex brand. (Durex will inevitably lend it a catchier name.) The condom may be commercially available there by the end of this year. To reach the American market, though, Durex will have to prove that CSD500 is "safe and effective compared to oral PDE 5 inhibitors" — in other words, Viagra, says a sexual medicine expert quoted by CBS. As such, there is no timetable for an American release at the moment.

Could it lead to more safe sex?

The official aim of the condom is not recreational. In fact, says Katherine Hobson at the Journal, the comparison with Viagra isn't quite right, since this product is "intended not for men with erectile dysfunction in general, but those who specifically have difficulties keeping an erection when using a condom." Adam Glickman, founder of the online store Condomania, says that even if the drug does not help enhance sexual performance, it will encourage men who avoid condoms to change their ways. This is one more step "in the process to 'normalize' condoms, which is what is really required to change attitudes and, ultimately, behavior," he says, as quoted by Portfolio.

Sources: Wall Street Journal (2), CBS, Portfolio