Amphetamine

Originally published July 27, 2019

Updated November 25, 2025

Amphetamine is a central nervous system stimulant used medically to treat conditions such as ADHD and narcolepsy, but also as a doping substance to increase alertness and physical performance. Although it may improve vigilance and anaerobic performance, its use involves significant risks, including cardiovascular complications, psychotic symptoms, and the dangerous masking of physical exhaustion.

Amphetamine is a central nervous system stimulant. Being chemically related to catecholamines, it induces the release of noradrenaline. Noradrenaline, in turn, induces classic sympathetic effects, such as increased heart rate, blood pressure, and respiration [1].

Amphetamine was synthesized in 1887 and its medicinal use began in the 1930s. Due to its stimulating effect, amphetamine was already used during World War II [2]. Amphetamine can therefore be seen as one of the first substances used for doping outside competitive sports [3]. A number of derivatives have been developed from amphetamine. These include substances such as methamphetamine, methylenedioxyamphetamine (MDA) and methylenedioxymethamphetamine (MDMA, or ecstasy) [4].

Amphetamine is well absorbed from the gastrointestinal tract and is available in tablet form. It can also be administered intranasally or intravenously [2]. Amphetamine has a rather long half-life, averaging approximately 19 hours [5].

Medical use

Amphetamine and its derivatives are used in the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy. They enhance concentration and reduce restlessness, among other things. The effects of the medication often appear quickly. Pharmacotherapy for ADHD can be initiated by a specialist familiar with behavioural disorders. There have been attempts to develop weight-loss drugs from amphetamine derivatives without the adverse effects of amphetamine. These attempts have not been entirely successful, however [2].

Use as a doping substance

The effects of amphetamine on physical performance have been researched since the 1950s. Amphetamine has been found to enhance anaerobic performance, but it has little or no effect on aerobic performance. Dosage plays an important role in its effects on performance. Large doses appear to increase aggressiveness, whereas smaller doses increase alertness. The main effects of amphetamine on performance are related to improved reaction time when fatigued, increased strength and endurance, increased lactic acid levels during maximal exertion, and reduced body fat [4]. Amphetamine may also be used to increase aggressiveness during training [10].

Because amphetamine reduces appetite, it can be used to enhance weight loss. Amphetamine and its derivatives have therefore been used as weight-loss drugs, but due to their adverse effects, they are no longer used medically for this purpose [2].

Amphetamine can also be used for so-called brain doping, in other words, to enhance cognitive abilities. Amphetamine use aims to keep the user alert and improve learning outcomes or the ability to cope with work, for example. However, no benefit from amphetamine has been demonstrated for healthy young people. On the contrary, delusional thoughts and feelings of panic may impair performance [2].

Adverse effects

Some of the adverse effects of medicinal amphetamine use include insomnia, loss of appetite, anxiety, psychotic symptoms, and increased heart rate and blood pressure. An increased risk of psychosis and mania has been observed, particularly at higher therapeutic doses. Other adverse effects associated with amphetamine use include sweating, headache, rapid breathing, tremors, and joint and muscle pain [2, 4, 11].

Especially when combined with heavy physical exertion, amphetamine may trigger sudden death or increase its risk through arrhythmias or heatstroke. Amphetamine has been linked to a number of fatalities in sports [4, 5].

Fatigue and exhaustion are important sensations and protective mechanisms that protect our bodies from dangerously high levels of physical strain [6]. These sensations may be overridden by the effects of amphetamine, allowing performance intensity to increase. Consequently, muscle temperature may rise to dangerously high levels during and after exertion [7].

All stimulants with a chemical structure similar to amphetamine can induce catecholamine-mediated cardiotoxicity [8, 9]. Elevated catecholamine levels can lead to vasoconstriction, rapid heartbeat, and high blood pressure, resulting in an insufficient oxygen supply to the heart. This may lead to cardiac hypertrophy, fibrosis, and necrosis [8].

In most cases, personality changes resulting from prolonged use of small doses can be expected to gradually reverse after discontinuation. However, prolonged use of large doses may cause permanent behavioural changes, such as paranoia [2].

Anabolic steroids can also cause harmful changes in cardiovascular function, behaviour, and mental health. The combined use of anabolic steroids and amphetamine may further intensify these adverse effects.

Tolerance to many of the effects of amphetamine develops relatively quickly. A person dependent on amphetamine may become psychotic, aggressive, and antisocial. Discontinuation of amphetamine use may be associated with depression [2].

Joni Askola
Master of Health Sciences (MHSc),
Dopinglinkki

Read more about other stimulants and weight loss drugs:

• Ephedrine
• Clenbuterol
• Dinitrophenol (DNP)
• Diuretics
• Methylphenidate
• Modafinil
• Thyroid hormones