One of the biggest issues with an unregulated drug market is the presence of adulterants. Whether it’s fentanyl-laced heroin, levamisole cutting cocaine, or 25I posing as LSD, the presence of cutting agents often causes more harm than the illicit drugs themselves. Researchers in Santa Catarina, Brazil, recently examined the purity and adulterants found on over a million LSD blotters seized since 2011 from roughly 1400 different sources. In 2011, every single sample tested positive for only LSD. But in 2014, less than 0.1% of blotters had LSD — instead, they found novel hallucinogens (NBOMe and DOx), fentanyl analogues, extasy, cathinones, and other modern designer drugs. All of these chemicals can cause a lethal overdose, unlike LSD. As of 2017, about 18% of tabs sold as LSD actually contained LSD. A hallucinogen called 25I was one of the most common adulterants in recent years. Luckily, this drug can be distinguished from LSD by the consumer — 25I has a strong bitter taste, whereas LSD is tasteless.