Everyone has heard of amphetamines and how addictive they can be. But what are amphetamines, and how do they work?

Amphetamines are compounds that stimulate the peripheral and central nervous systems. They are taken because they make the user feel alerted, confident and euphoric. The drawback is that amphetamines can be addictive if they’re overused and psychosis or break with reality, is one of the symptoms. In 2005, according to a U.S. Department of Health and Human Services SAMHSA report, about 9 percent of all drug-related trips to hospital emergency rooms were caused by amphetamine or methamphetamine use.

Amphetamines all share the amphetamine molecule. The scientific name for this molecule is alpha-methylphenethylamine. This means that amphetamines are a subgroup of phenylethylamines, which include the drug Ecstasy or MDMA. Phenylethylamines are stimulants and have mild hallucinogenic properties. Alpha-methylphenethylamine is a volatile liquid that grows dark over time. When it’s combined with sulfuric acid, the product formed is a stable, off-white powder.


When looked at on the molecular level, amphetamines also greatly resemble neurotransmitters like norepinephrine, epinephrine, and dopamine. So, it’s not surprising that the effect of amphetamines on the body resembles the action of epinephrine or adrenaline, a compound that the adrenal glands release into the bloodstream when the person is under stress. But the effects of adrenaline and amphetamines are different. Adrenaline stimulates receptors in neurons or nerve cells that respond to norepinephrine, but amphetamines cause the neurons to release their stores of norepinephrine. Amphetamines also suppress the release of monoamine oxidase, which helps inactivate some of the norepinephrine. They also block the reuptake of norepinephrine. Reuptake is what happens when the norepinephrine is taken from the synapse or junction between the nerves and returned to the neuron.

The stimulation that users of amphetamines receive comes from the central nervous system. The amphetamines stimulate the release of neurotransmitters like dopamine and norepinephrine into the synapses between neurons and the synapses between the neurons and the cells they control, like muscle cells. This can also include cardiac muscle cells. High doses of amphetamines mimic elevated levels of neurotransmitters. The results are euphoria, alertness and a burst of energy as well as the suppression of appetite. Other short-term effects are dry mouth, tremor, sweating, rapid heart beat and elevated blood pressure. But the nerve cells only release their neurotransmitters at a fixed rate, so this puts a limit on how effective amphetamines can be. Because of this, the person’s tolerance for amphetamines increases over time, and he or she will need to take more to get the same effect.

Also, the period of taking large doses of amphetamines is followed by a recovery period that allows neurotransmitters to build up in the neurons. During the recovery period, the activity of neurotransmitters is little, and the user endures depression and fatigue even while he or she is building up a tolerance for the drug. Other symptoms are ulcers, violent mood swings, and malnutrition. Taking frequent, massive doses of amphetamines can cause lad to brain damage that causes slurred speech and confusion.

An overdose of amphetamines can lead to the dopamine receptors in the nervous system being overstimulated. This results in symptoms that resemble an excess of dopamine in schizophrenics. One of these symptoms is amphetamine psychosis. This condition is a risk to long-term users of amphetamine who need to take more and more of the drug to experience something like their first experience of it.

How It’s Taken

The fastest way to get amphetamines into the blood is to smoke or inject it, but people also snort or ingest it. The effects usually come on within 15 minutes to a half an hour and can last from four to six hours. Though amphetamines can pass through the blood-brain barrier and affect the central nervous system, some types of amphetamines cross the barrier with more ease because of their polarity. Because methamphetamine is less polar that amphetamine, it gets into the central nervous system quickly.

After a while, amphetamine is deactivated by liver enzymes then eliminated by the body. This isn’t true with methamphetamine and so its affects last longer. For the body to disable and remove methamphetamine, another enzyme needs to remove the methyl group from the drug to leave amphetamine behind. The amphetamine then stays active until the liver enzymes deactivate it.


When a person withdraws from amphetamines, he or she can experience despondency and exhaustion as well as great hunger. He or she can also be anxious, suicidal and have very vivid dreams. The withdrawal period can last for some days but can extend into weeks or even months if the user abused the drug heavily. People who believe that they are dependent on or addicted to amphetamines should seek inpatient treatment for their addiction. In an in-patient facility, they can recover in a non-stressful environment with the support of medical staff, social workers, therapists, nutritionists and other professionals.

Amphetamine overdose rarely results in death, but the symptoms are unpleasant. They include amphetamine psychosis, the increase in body temperature, the spike in blood pressure and muscle pain.


Amphetamines were first synthesized in 1887, but it took decades for researchers to notice its health effects. Because amphetamines dilated or opened up the bronchial passages in the lungs, it began to be used to treat asthma attacks. It was later used to treat narcolepsy and was used in World War II to help soldiers stay awake and alert, though by then its harmful psychological effects were noticed. Amphetamines use to keep soldiers awake extended even into the Vietnam War in the form of “bennies” or benzedrine pills. After World War II, amphetamine was sold over-the-counter as appetite suppressants and pep pills. By 1970, amphetamines were classified as Schedule III drugs by the U.S. Controlled Substances Act and became Schedule II drugs the next year.

Schedule III drugs are drugs that have a moderate or low risk of the user becoming dependent. The use of Schedule II drugs poses a higher risk for abuse than Schedule II drugs and can lead to a profound dependence both psychologically and physically. They’re considered quite dangerous drugs.

Types of Amphetamines

  • Ephedra
    • Ephedra is a plant that contains ephedrine. It’s different from other amphetamines in that it acts directly on the norepinephrine receptors in the nervous system. It also causes norepinephrine to be released from the body’s stores. Because of this, it’s called a mixed action norepinephrine receptor agonist.
  • Adderall
    • Adderall is taken for ADHD or attention deficit hyperactivity disorder and for a condition called narcolepsy, where a person falls to sleep uncontrollably. It’s a combination of a dextro and levo amphetamine. These are two molecules that make up amphetamine sulfate. They’re mirror images of each other. A chemical process produces equal amounts of the two, which is called a racemate. Dextro amphetamine is a powerful stimulant, but levo amphetamine is a weak stimulant and is used as an appetite suppressant. About 6.4 percent of full-time college students use Adderall for nonmedical purposes, according to the 2006-2007 SAMHSA survey. These college students were also more apt to use other nonprescription drugs and alcohol. Adderall should never be taken with an MAO inhibitor. It shouldn’t even be used if the patient has only recently stopped taking an MAO inhibiter.
  • Methylphenidate
    • Methylphenidate is also known as Ritalin. Like Adderall, methylphenidate is prescribed to treat hyperactivity and attention deficit disorder as well as narcolepsy. When it’s prescribed, it comes in tablets, capsules, powders or solution.
  • Benzedrine
    • Benzedrine became a notorious street drug used to keep people awake. The pills were known as “bennies.” However, it first became famous in the 1930s as a component of the benzedrine inhaler, which was used to treat asthma. It was a wad soaked in amphetamine and placed in a tube. People abused it by opening up the inhaler and washing the amphetamine from the wad with an alcoholic drink or with water and drinking it. By the 1950s, users were extracting the benzedrine and injecting it. People also used it to help lose weight as amphetamines take away the appetite. Benzedrine became very popular among the Beatnik set in the 1950s.
  • Methamphetamine
    • Methamphetamine is also called crystal meth, ice and tweak. Besides being harder to deactivate in the body, it’s also more fat soluble than regular amphetamines. This is what also makes it easier for it to cross the blood-brain barrier. The methamphetamine high also lasts a few hours longer than that for the regular amphetamine. The user begins to feel exhausted and depressed as the effects wear off, and the urge to get another dose is very strong. However, the second or third hit of the drug is never as pleasurable as the first hit. Some users can take methamphetamine continuously for days to recapture it. This makes the risk of amphetamine psychosis high.