Drugs are any substance that is somehow consumed by an individual with a temporary effect on their physiological and often psychological state of their organism. Drugs are often used for medical purposes, such as anesthesia or as cures for psychological diseases. Still, most drugs have strong side effects with addiction being the most important one. As governmental drug control is often very strict, drug consumers try to find other means of purchasing the drug they want. Internet dark markets offer them the opportunity to buy drugs with Bitcoin or other cryptocurrencies. The Bitcoin drug market is growing over time as more people get used to new payment technologies. Still, blockchain may be also used for developing legal drug purchasing systems. Blockchain technology may help with eliminating counterfeit drugs by recording all the information about licensed products.