In addition to the chemical properties of the substance itself, the dose, and how often you are taking it, the route of administration, that is the method in which a substance is taken into the body, has a critical role in influencing the effects of the substance. Specifically, the addictive potential of a substance is largely determined by the speed at which that substance is able to reach the brain, where, put very simply, the faster it can reach the brain, the more likely it is to be addictive.
From quickest to slowest route of administration, below are the 4 most common methods for taking substances:
- Inhalation, or smoking, is the most common way to use substances, and fastest route to the brain, causing almost instantaneous effects. The smoke goes into the lungs, where it is quickly absorbed into the bloodstream, and heads up to the brain. Potential health side effects to smoking include: high blood pressure; heart disease; mouth, throat and lung cancer; heart attacks and strokes; pneumonia and other lung infections.
- Injection is when a substance is injected directly into the blood stream, where is it then carried to the brain, causing effects typically within 3 to 5 seconds. There are 3 different ways a substance can be injected: subcutaneously (directly into the soft tissue just beneath the skin), intravenously (directly into a vein), and intramuscularly (directly into a muscle found deeper in the body). Potential health side effects include increased chance of infection due to contaminated needles or substances, scarring of the veins, arterial damage, which can lead to haemorrhaging, gangrene, and thrombosis.
- Snorting or sniffing is when a substance is taken through the nose, where 30-60% of the drug enters the bloodstream via the mucus membrane in the nose, and the stomach, causing effects usually within 15 minutes. Potential health risks include damage to the inside lining of the nostrils, nasal cavity, and the septum, spread of infectious diseases such as hepatitis C and HIV, and various other risks depending on the substance.
- Ingestion, or taking a substance orally, is one of the simplest ways of taking substances, where the substance is taking through the mouth, and enters the bloodstream via the lining of the stomach or the intestines. Swallowing is one of the safest ways to take substances for several reasons, including the naturally slower absorption process and the defense mechanisms of the digestive system (e.g., designed to induce vomiting in case of a risky foreign substance). However, there have been cases of people dying from swallowing cocaine; any route of administration comes with potential risk.