How Long Does Heroin Stay In Your System?

After ingestion, most opiates are rapidly absorbed and metabolized. Psychoactive drugs are simple, small molecules. Drugs that are snorted, injected or taken by mouth are easily absorbed by the body. For a drug to be psychoactive, it must reach the brain. The brain is mostly made of fat. Therefore, a drug must be either fat-soluble or else converted in the body to form a substance that is fat-soluble. Heroin is made of the morphine molecule with the addition to two acetyl groups. This allows it to reach the brain more effectively.  Heroin effects are swift, depending on the dose and whether they are injected, smoked or snorted. When injected into a vein, the onset of euphoria occurs in seven to ten seconds. Effects peak for one to two hours and most wear off in four to five hours, although a sedated feeling can last longer.

Heroin is highly addictive and users risk severe withdrawal symptoms when they stop taking the drug. Withdrawal symptoms usually begin 6 to 12 hours after the last dose.  Withdrawal symptoms can last from 5 to 12 days.