Intravenous drug use involves the administration of drugs directly into the bloodstream using a syringe and needle. This method allows for rapid effects, as the drug quickly circulates throughout the body. Common substances used in this way include heroin, methamphetamine, and certain prescription medications. While intravenous drug use can provide immediate relief or euphoria, it also carries significant risks. These include the potential for overdose, transmission of infectious diseases like HIV and hepatitis, and complications from improper injection techniques. Safe practices and awareness of these risks are crucial for individuals who use drugs in this manner.