The user then injects the sub- stance either subcutaneously or intravenously. The effects of injecting heroin are felt within minutes and last three to four hours, depending on the dosage. Street heroin can be a white or brownish powder. Psychological Effects of Opiates Like other depressants, opiates produce a tranquil and euphoric effect. Some users combine opiates with a stimulant such as cocaine.
Psychological dependence is probable with continued use of opiates.
When a user becomes dependent, finding and using the drug becomes the main focus of life. The physical effects of opiates depend on the opiate used, its source, the dose and the method used. Opiates slow breathing, heart rate and brain activity. Opiates depress appetite, thirst and sexual desire. The body's tolerance to pain is increased.