Rather than attempt to change the actual size of the penis, one may make it appear bigger, by trimming the pubic hair or by losing weight, which may be of particular use if one is overweight.
"Penis enlargement pills" or ointments are commonly offered over the Internet; these, for the most part, are scams.
Analyses performed by Flora Research of California and by the University of Maryland have uncovered harmful contaminants in a number of "penis enlargement" pills. Contaminants found included mold, yeast, dangerous E. coli bacteria, pesticides, and lead. Dr. Michael Donnenberg of the University of Maryland has described herbal pills marketed by Performance Marketing Ltd. as having "heavy fecal contamination", possibly from animals grazing near the plants harvested for herbal ingredients. There may however be a placebo effect i.e. a psychological effect of making the user think he has a larger penis, and increasing his confidence, when there is no actual change to his penis size.
Another method which is often advertised is the penis pump. This is a cylinder that is fitted over the penis, with a manual or motorized pump to create suction. As the apparatus creates a vacuum around the penis, blood is drawn into the penis causing it to become engorged. The higher the vacuum, the higher the blood-pressure becomes within the penis; excessive pressure causes vascular damage rather than a harder penis.
Pumping with either type of pump must be done very carefully to avoid injury: manufacturers' instructions should be followed. Manual pumps often recommend a gentle pump followed by a pause, then repeated. Over-enthusiastic pumping can burst blood vessels and form blisters. In some cases the testicles can be unexpectedly pulled into the cylinder and cause severe pain and injury. It is also believed that the rim of the cylinder can cut into the skin and over time cause damage to the ligaments surrounding the penis. These dangers are easily avoided by following instructions. Impatiently pumping without reading explanatory material can produce too much suction (anything over 10 mm Hg) and cause permanent injury. Attempts at using vacuum cleaners units for this purpose have resulted in severe injury as the machine produces far too much suction. If the base unit is used without a hose there is also the danger of coming into contact with the rapidly-rotating fan.
Penis pumps are also used for masturbation. In August 2006, Oklahoma district court judge Donald Thompson was sentenced to four years in prison for repeatedly having masturbated with a penis pump while presiding over court cases.