Vacuum Erection

Vacuum erection devices (VEDs) or vacuum constriction devices (VCDs) typically have three main parts: 

1. A clear plastic cylinder with an opening at one end to place the penis 
2. A pump that creates a vacuum in the cylinder by drawing air out. The reduced air pressure increases blood flow to the penis, which causes an erection. FDA-approved devices have pop-off valves to limit the amount of vacuum pressure, which decrease the chance of penile injury. The pump can be battery- or hand-operated. 
3. An elastic ring, which you place on the base of the penis once you achieve erection to reduce blood flow out of the penis and help sustain the erection. Much like condoms, the rings come in different shapes and sizes for comfort and individual fit. Most VEDs/VCDs makers suggest taking off the ring after 30 minutes to minimize risk of injuring the penis 

Consult your doctor before buying or using a VED to find out if the device is appropriate for your specific needs, even if it is available over the counter. Ask your doctor to recommend a device since many (mostly those available on the Internet) are not FDA-approved and can result in penile injury. 

The risks or side effects from these devices are usually minor. However, you may experience bruising, skin irritation, numbness, and/or loss of sensitivity. Others have reported cold or pinched scrotum while wearing the constriction rings.