4-Methoxymethamphetamine (PMMA, para-Methoxymethamphetamine) is a stimulant and psychedelic drug closely related to the amphetamine-class serotonergic drug para-methoxyamphetamine (PMA). Little is known about the pharmacological properties, metabolism, and toxicity of 4-Methoxymethamphetamine. Because of its structural similarity to para-methoxyamphetamine, which has known toxicity in humans, it is thought to have considerable potential to cause harmful side effects or death in overdose. In the early 2010s, a number of deaths in users of the drug MDMA were linked to misrepresented tablets and capsules of 4-Methoxymethamphetamine. In 2010–2013, a cluster of 29 fatal poisonings related to the toxic designer drug 4-Methoxymethamphetamine was revealed in Norway. The toxicity of PMMA is regarded as substantially higher than for amphetamine, methamphetamine, and MDMA, as indicated by 131 fatal and 31 nonfatal poisonings associated with the abuse of 4-Methoxymethamphetamine worldwide. The toxicity of 4-Methoxymethamphetamine is positively correlated with the 4-Methoxymethamphetamine dose and the blood drug level, but the existing literature indicates that certain human subjects may have an increased risk of 4-Methoxymethamphetamine toxicity. 4-Methoxymethamphetamine, like PMA most likely acts as a selective serotonin releasing agent (SSRA) with weak effects on dopamine and norepinephrine transporters. However, relative to MDMA, it is considerably less effective as a serotonin releaser with properties more akin to a reuptake inhibitor in comparison. It evokes robust hyperthermia while producing only modest hyperactivity and serotonergic neurotoxicity, substantially lower than that caused by MDMA.

DL-Methamphetamine (also known as +/- Methamphetamin) is a central nervous system stimulant and sympathomimetic with actions and uses similar to DEXTROAMPHETAMINE. The smokable form is a drug of abuse and is referred to as crank, crystal, crystal meth, ice, and speed. Methamphetamine is a mixture of two isomers. One isomer called Dextro, or D Methamphetamine, is active as a central nervous system stimulant and it is a DEA Schedule 2 controlled drug commonly called “Meth” or “Speed”. Desoxyn, a prescription drug also contains D Methamphetamine. The other isomer, Levo, or L Methamphetamine is not a DEA controlled drug. It is found in an over the counter medicine called “Vicks Inhaler” or as the prescription drug, Selegiline. (+)-methamphetamine is the more physiologically active isomer. In addition to some medications, L Methamphetamine can be produced in the illegal production of street Methamphetamine.

Amphetamine is a potent central nervous system (CNS) stimulant that is used in the treatment of attention deficit hyperactivity disorder (ADHD), narcolepsy, and obesity. Amphetamine was discovered in 1887 and exists as two enantiomers: levoamphetamine and dextroamphetamine. The mode of therapeutic action in ADHD is not known. Amphetamines are thought to block the reuptake of norepinephrine and dopamine into the presynaptic neuron and increase the release of these monoamines into the extraneuronal space. At higher dosages, they cause release of dopamine from the mesocorticolimbic system and the nigrostriatal dopamine systems. Amphetamine may also act as a direct agonist on central 5-HT receptors and may inhibit monoamine oxidase (MAO). In the periphery, amphetamines are believed to cause the release of noradrenaline by acting on the adrenergic nerve terminals and alpha- and beta-receptors. Modulation of serotonergic pathways may contribute to the calming affect. The drug interacts with VMAT enzymes to enhance release of DA and 5-HT from vesicles. It may also directly cause the reversal of DAT and SERT. Several currently prescribed amphetamine formulations contain both enantiomers, including Adderall, Dyanavel XR, and Evekeo, the last of which is racemic amphetamine sulfate. Amphetamine is also prescribed in enantiopure and prodrug form as dextroamphetamine and lisdexamfetamine respectively. Lisdexamfetamine is structurally different from amphetamine, and is inactive until it metabolizes into dextroamphetamine.