Short-term Effects

• Once administered, the effects of heroin last approximately three to six hours.
• Soon after administration, heroin crosses the blood-brain barrier and is converted to morphine in the brain, which binds rapidly to opioid receptors, causing the user to experience a "rush" of euphoria.
• Restlessness, nausea, vomiting, and severe itching may occur as the result of the dose required to produce the sought after high.
• With moderately high doses, the body feels warm, the extremities heavy, and the mouth dry.
• Drowsiness sets in for several hours following the initial rush. The user may alternate between a wakeful and drowsy state, sometimes referred to as "nodding out" due to the user's head dropping down as they drift off into a state of sleep.
• Heroin's effect on the central nervous system causes mental functioning to be clouded. Breathing becomes gradually slower as the dose is increased.
• Large doses can cause the pupils to contract to pinpoints, the skin to become cold, moist, and bluish, and respiration to depress profoundly, possibly resulting in death.

Long-term Effects of Heroin

• A long-term user of heroin may experience one or more of the following conditions.
  • Addiction
  • Infectious diseases, for example, HIV/AIDS and hepatitis B and C
  • Scarred and/or collapsed veins
  • Bacterial infections of the blood vessels and heart valves
  • Abscesses and other soft tissue infections
  • Arthritis and other rheumatologic problems
  • Liver or kidney disease
  • Lung complications