In the United States, the Drug Enforcement Administration (DEA) is the agency tasked with regulating the use of controlled substances, including prescription and over-the-counter drugs with a potential for abuse under the Controlled Substances Act (CSA).1 Additionally, illegal drugs fall under a number of regulations and laws that prevent their sale, distribution, and consumption within the country’s borders, according to the DEA’s mission and purpose.2

However, even with these laws in place, there are many ways to create and use drugs that get around the stated regulations. Since the DEA classifies drugs into schedules based on potential for abuse and dependency, in order for novel substances intended for human consumption to meet criteria for criminal prosecution, they must be proven as structurally or pharmacologically similar to an already-known dangerous, scheduled substance.3

And here is where designer drugs find their loophole.

Designer drugs—otherwise known as synthetic drugs, research drugs, or research chemicals—are manufactured to chemically resemble illicit drugs, but may be purchased legally because drug manufacturers constantly change the chemical structure to circumvent drug laws.4

Often marketed as herbal substances, designer drugs are not regulated by the law in many instances, and there is no oversight of the involved manufacturing processes.5 Two examples are bath salts and spice, as they are commonly known on the grey market.

"In fact, designer synthetic drugs are found to be more potent and dangerous than their street drug counterparts."
Bath salts and spice are often abused for their cocaine- and marijuana-like effects, respectively, and both have been associated with fatalities.4 People who abuse designer synthetic drugs have suffered a number of negative health outcomes that include anxiety, seizures, hallucinations, loss of consciousness, and significant organ damage.5

The recent growth in the use of synthetic stimulants or hallucinogens is due to their ability to mimic the effects ofcocaine, LSD, MDMA, or methamphetamines. In fact,designer synthetic drugs are found to be more potent and dangerous than their street drug counterparts: One chemical derivative was found to act 50 times more strongly than cocaine, vastly increasing its potential for abuse and toxicity.4

Making them more dangerous is the fact that they are easily accessible in retail outlets and online, which has made them especially popular among adolescents.5 This has led to increasing numbers of designer drug–related E.R. visits.

A 2012 report by the Substance Abuse and Mental Health Services Administration showed11,406 emergency department visits due to a synthetic cannabinoid product during 2010.5 A year later, that number increased 2.5 times.5 A youth survey on drug-use trends found that 1 in 9 12th graders in the United States reported using synthetic cannabinoids in the previous year.6 It was found to be the second-most frequently used illegal drug among high school seniors after marijuana.6

Historically, there have been a number of examples of designer drugs. Some of the earliest forms of designer drugs were derivatives of opium. For example, heroin was a chemically modified version of the morphine alkaloid extracted from the opium poppy.7 Back then, lawmakers struggled to find a way to control the widespread use of these early synthetics. In the U.S., taxes were first levied in an attempt to curb opium use prior to the drug being proclaimed illegal by the federal government.8 Years later, the Controlled Substance Act was a way to consolidate several laws meant to control a number of these illicit drugs, providing a mechanism for substances to be added, removed, or transferred from one category to another.8

However, designer drugs have continued to evolve over the years, as their manufacturers strive to stay ahead of the enforcement agencies.