“Explosive sex. Every night, at any age!” reads the subject line of a spam e-mail I just received. E-mails claiming to boost men’s and women’s libido and intensify pleasure or increase penis size are among the top three junk e-mail topics, according to one anti-spam technology company. And these products are flying off shelves. But do they deliver the performance they promise? The Food and Drug Administration reports that no nonprescription ingredients have proved effective—or safe—as sexual enhancers. They can even cause headaches, changes in blood pressure, irregular heartbeats, blindness and chest pain. If you’re experiencing sexual performance problems, seek treatment from a medical professional. Your symptoms may indicate the presence of a serious disease, like diabetes, prostate cancer or even heart failure. These products can make health problems worse or even prove fatal. Save your money for a visit to your doctor.