The length of your penis can decrease by up to an inch or so for various reasons. As you get older, your penis and testicles may get slightly smaller. One reason is the buildup of fatty deposits in your arteries reducing blood flow to your penis. This can cause withering of the muscle cells in the spongy tubes of erectile tissue inside your penis. The erectile tissue becomes engorged with blood to produce erections.
This is just one of many misconceptions about the link between masturbation and penis size. Masturbation is a perfectly normal and natural activity, and it has no harmful effects on your health, including your sexual health. But people definitely have theories — none of which stand up to the rigor of scientific inquiry. One possible source is the notion that ejaculation reduces your testosterone levels. Many people also believe that testosterone levels are responsible for making your penis grow and shrink. Again, no. This important hormone is instrumental in your growth during your teenage years, especially.
In some cases, the penis just seems smaller than it used to be. In others, there is actual penile shortening. When a man puts on weight, the extra belly fat can bury the penis, hiding the penile shaft. As a result, the penis looks shorter than it actually is.
Most men have wondered, at one point or another, whether it's possible for their penises to shrink. While this sounds like something out of a sci-fi movie, unfortunately, this fear does have some truth to it. While it's not really possible for penises to gradually shrink inch by inch, it's true that due to age and lifestyle choices, your penis could potentially lose the ability to maintain a consistent level of tumescence. So what is tumescence? Well, it's basically a fancy word for erection firmness , says Mary Samplaski, MD , urologist and the director of male infertility at the University of Southern California.