4-methylthioamphetamine

4-methylthioamphetamine (4-MTA), synthetic psychoactive drug known primarily for its effects on serotonin, a monoamine neurotransmitter in the brain that is associated with the regulation of mood. Chemically, 4-methylthioamphetamine (4-MTA) is classified as an amphetamine, and it is structurally very similar to other designer amphetamine drugs, most notably MDMA (3,4, methylenedioxymethamphetamine; also known as Ecstasy). However, it has distinct properties and highly dangerous side effects. 4-MTA has no legitimate uses in medicine or research and is a controlled substance in many countries.

Effects

4-MTA acts by increasing serotonin release and by inhibiting the reuptake of serotonin into neurons and its breakdown by the enzyme monoamine oxidase A. These actions result in the accumulation of serotonin in the brain. Unlike other stimulants, 4-MTA has limited effects on other monoamines, including dopamine and norepinephrine, which are associated with traditional stimulant effects, such as euphoria and increased energy.

The buildup of serotonin in the brain induced by 4-MTA can cause significant mood changes and altered perception, as well as increased risk of serotonin syndrome. Serotonin syndrome is characterized by agitation, altered mental state, drowsiness, headache, rapid eye movement, restlessness, sweating, and tachycardia (elevated heart rate); in severe stages, hyperthermia (overheating), muscle rigidity, and seizures may occur. Left untreated, serotonin syndrome can result in death.

Recreational use

In the early 1990s 4-MTA was investigated by pharmacologist David E. Nichols and colleagues at Purdue University to better understand the pharmacological actions and structure-activity relationships of substituted amphetamines. In 1997, however, the drug was discovered in a clandestine laboratory in the Netherlands, where it was being produced as a recreational substance. In its illicit use, it was sold as an alternative to Ecstasy and was sometimes even misrepresented as Ecstasy; it was marketed under street names such as “flatliners” and “golden eagle.” 4-MTA quickly gained notoriety for its dangerous side effects, including the risk of severe serotonin syndrome.

As a recreational drug, owing to its lack of euphoric effects and high risk of severe side effects, 4-MTA never gained significant popularity. Moreover, the drug’s slow onset, particularly relative to that of Ecstasy, potentially leads users to take more of the drug in order to experience its effects, increasing the likelihood of adverse events and fatal overdose. The drug also has long-lasting effects, which adds to these risks. The severe and unpredictable health risks associated with 4-MTA resulted in its classification as a dangerous substance with no safe level of use. It is controlled under international drug laws, including the United Nations Convention on Psychotropic Substances.