Contrary to popular belief, your penis is not a muscle, nor does it contain a bone. It's better to think of it as a kind of sponge, which, when flaccid, is soft and malleable, but can quickly become engorged when filled with blood. Two large cylindrical chambers, the corpus cavernosum and the corpus spongiosum (see?), fill with blood during arousal, causing your penis to harden and grow in size.
Not all agree though. Male enhancement pills and supplements seem sometimes to satisfy men who are looking for something that will not be permanent but are worried more about performance. “Penis pills don’t require a device or consistency and practice. I’ve seen pills work at making the penis not only harder, but also last longer. I always say that men have never seen the full potential of their penis. Until you pop some penis pills or try a cock ring or a penis pump, you will have never seen what your penis is capable of,” says Leo Debois of AdamsToyBox, a male-focused adult toy store.
And if you're worrying about your size pleasing your partner, remember that penetration is just one part of sex, and everyone's preferences are different. Many women don't even orgasm from penile-vaginal sex, for instance, and other people don't care very much about size or length. The size of your penis could possibly be unrelated entirely to your partner's ability to experience pleasure.
The question most men probably care for most. While many woman claim that penis size isn’t important for them and it’s all about the right technique and a loving partner treating them well, that’s only half the truth. In totally anonymous surveys, the number of women claiming that penis size is important for them, at least from a aesthetic viewpoint, is significantly higher than in face to face surveys. This fact doesn’t mean a smaller penis can’t satisfy a women, it doesn’t mean you can’t have a perfect sex life with a small penis, but the the harsh truth is: Size matters, at least for some women. No need to panic if you have a small penis, according to a combined study of several reasearch institutes since 1942, 85% of all women are happy with the penis size of their partner, while only 55% of all men are happy with their own penis. So, the percieved problem is bigger than the real one.
The average flaccid penis is between 3.5 and 5 inches long and 3.5 inches around, while the average erect penis is a little more than 5 inches in length and 4.5 inches in girth. Some men feel inadequate, even though their penis size is perfectly normal. Nearly 70% of men say they’re not happy with their size, and about half wish they could be larger.
Some men seek injections of natural and synthetic fillers to increase the girth of the penis. Others seek surgery if a smaller penis size or penile abnormality (like hypospadias) is interfering with the ability to urinate or quality of life. Small penis size usually is not an indication for surgery to treat infertility. In such cases, assisted fertility procedures may be the better option.