Depending on the type of drug used, the high may be short and intense (such as heroin which is usually 15-30 minutes) or longer lasting (such as morphine which usually lasts 4-6 hours).
Short-term Health effects:
Long-term health effects:
There are also additional health effects if the drug is injected. These include heart problems (infections), pulmonary embolisms (blood clots in the lungs), gangrene (if the injection site becomes infected), and chronic infections passed through blood like viral hepatitis and HIV if the user is using an unsterile needle.