The vacuum pump. This is a cylinder that sucks out air. You stick your penis in and the resulting vacuum draws extra blood into it, making it erect and a little bigger. You then clamp off the penis with a tight ring -- like a tourniquet -- to keep the blood from leaking back into your body. What are the drawbacks? The effect only lasts as long as you have the ring on. Using it for more than 20 to 30 minutes can cause tissue damage. This is sometimes used as a treatment for erectile dysfunction, but has not been proven to actually increase the size of the penis.
These products usually contain vitamins, minerals, herbs or hormones that claim to enlarge the penis. Despite their impressive claims, there's absolutely no clinical evidence that these products work and some may even be harmful. The University of Maryland in the US carried out an analysis on some of these and found traces of lead, pesticides, E. coli bacteria and animal faeces.
Interestingly, studies suggest that men attribute more importance to penis size than their female partners. Generally, what is more, important to women is a partner who is tender and caring. Discovering how your partner likes to be touched and caressed tends to make for better sex. The idea that a woman’s priority during sex is to be penetrated by a giant penis isn’t that accurate. In fact, it’s not the inside of the vagina where most of the pleasurable sensations come from, it’s on the outside, at the clitoris, where the most sensitive parts of a woman’s body can be found. You don’t need a big penis (or any penis) to stimulate her there. During intercourse, a woman’s vagina adapts to her partner’s penis, deepening, widening and lubricating during sexual arousal, so in this sense, the size is not so important. Also, a smaller penis is often preferable for oral and anal sex.