As we age, both men and women take longer to become sexually aroused, and may lose the urgency to have sex they once had. In men, waning testosterone levels can make a guy moody, irritable and depressed, as well as decrease his libido. In women, the hormonal changes of menopause may affect lubrication, arousal, orgasm, and, perhaps most significantly, sex drive.
But even so, the capacity to have satisfying sexual relationships does not disappear with age. We remain sexual throughout our lives, and many couples find that sex becomes more intense and intimate as they grow older. It's not as simple as less hormones equals less sex. It's all about lifestyle--exercise, diet, sleep, and a healthy engagement with life--and the quality of your relationship.