The research: For 12 weeks, the researchers kept tabs on nearly 2,000 ED sufferers who’d started taking the once-a-day drug tadalafil, a.k.a. Cialis. Apart from the increase in erections, the researchers recorded an 85% jump in sexual self-confidence thanks to the men’s newfound virility, a finding they based on the participants’ answers on psychologoical questionnaires administered at various points throughout the study period.   What it means: Self-confidence gains create a positive reinforcement cycle that leads to more sex and even better performance, the study shows. Pills that you pop just prior to sex, such as sildenafil (Viagra), also provide a significant confidence boost, according to a prior Journal of Sexual Medicine study. But because these drugs are more restrictive—you have to wait for the pill to kick in before you can have sex—they don’t buoy a man’s sexual self-confidence as much as a once-a-day solution, the authors argue, citing their study, as well as past research. They calculated roughly 8% of the study participants’ self-confidence gains were the result of their ability to be sexually spontaneous. The bottom line: “Interaction between functional, physiological and psychological factors is integral in managing patients with ED,” says Ash Tewari, MBBS, MCh, a professor and chair of the Milton and Carroll Petrie Department of Urology at Mount Sinai Hospital, who was not a member of the research team. “This paper highlights that improved sexual confidence in men receiving treatment with a long-acting PDE-5 inhibitor [such as tadalafil] occurs both directly via improved erectile function and indirectly via improved spontaneity and diminished time concerns.” More from Prevention: The Sex Issue 75% of Men Aren’t Dealing With