While labels on over-the-counter (OTC) erection pills and products may hint they are just like Viagra (sildenafil) or another erectile dysfunction (ED) drug, their benefits remain largely unproven.

Erectile dysfunction is often treated with medicines known as PDE-5 inhibitors, which include Viagra. But studies have demonstrated how other drug-free, like red grape juice, could combat ED.

It refers to the amount the Pentagon spends on erectile dysfunction medication annually: about $84m (£63m), according to the Military Times newspaper. In contrast, the Rand Corporation think tank ...