Life Cycle of a Penis
Experts explain how a penis changes in size, appearance, and sexual function as a man ages.
By David Freeman
Reviewed by Louise Chang, MD
It's no secret that a man's sexual function declines with age. As his testosterone level falls, it takes more to arouse him. Once aroused, he takes longer to get an erection and to achieve orgasm and, following orgasm, to become aroused again. Age brings marked declines in semen volume and sperm quality. Erectile dysfunction (ED), or impotence, is clearly linked to advancing years; between the ages of 40 and 70, the percentage of potent men falls from 60% to roughly 30%, studies show.
Men also experience a gradual decline in urinary function. Studies show that a man's urine stream weakens over time, the consequence of weakened bladder muscles and, in many cases, prostate enlargement.
And that's not all. Recent research confirms what men have long suspected and, in some cases, feared: that the penis itself undergoes significant changes as a man moves from his sexual prime -- around age 30 for most guys -- into middle age and on to his dotage. These changes include:
Appearance. There are two major changes. The head of the penis (glans) gradually loses its purplish color, the result of reduced blood flow. And there is a slow loss of pubic hair. "As testosterone wanes, the penis gradually reverts to its prepubertal, mostly hairless, state," says Irwin Goldstein, MD, director of sexual medicine at Alvarado Hospital in San Diego and editor-in-chief of The Journal of Sexual Medicine.