Contrary to popular belief, Viagra doesn’t increase sexual desire – it only potentiates your natural desire by relaxing the blood vessels in the penis. In other words, you still have to be up for it to be up for it. According to Murray Blacket, a psychosexual therapist, “before Viagra, erectile dysfunction was thought to be up to 90% psychological and 10% organic. With everything put out by the drug companies over the years, that’s now reversed. It’s seen as mostly an organic, physical problem.”