WHAT ARE POPPERS?
"Poppers" is the popular name for various alkyl nitrites, including isobutyl nitrite, butyl nitrite, and amyl nitrite.
Doctors used to prescribe amyl nitrite for heart patients in capsules that were broken or "popped" to release vapors.
Amyl nitrite is made and sold illegally, but most poppers are isobutyl nitrite or butyl nitrite sold in small brown bottles as "video head cleaner," "room deodorizer," or "leather cleaner."
The exact contents of these products are not known, and they are not safety tested.
WHAT ARE THE EFFECTS?
Poppers are used by sniffing the vapors from an open bottle. The effects are felt within a few seconds and last for 1-2 minutes.
Poppers cause muscles around blood vessels to relax, making your heart speed up to pump more blood. Oxygen-rich blood reaching the brain produces a "rush" sensation.
Because poppers cause muscles in the anus and vagina to relax, they are often used during sex.
http://dancesafe.org/documents/druginfo/poppers.php