Fentanyl is cheap to manufacture and its strong potency means it can be transported in smaller quantities more easily than other drugs. Fentanyl has partially replaced other opioids, specifically heroin, for trafficking into the United States. There are many variables when it comes to what people sell and buy, including price, purity, availability, and risk tolerance.
Locally, fentanyl may be sold to people who are seeking opioids, but it may also be combined into other drugs to stretch or strengthen the supply. For example, fentanyl is increasingly being found in fake versions of prescription pills - these are pills that might look like they are legitimate, but are really counterfeits that might not even include any of original medication that someone thinks they are buying. Fentanyl contaminations of other drugs may be intentional or unintentional, depending on availability and dealer. This makes every dose a gamble.