What Is Speed? The Amphetamine Stimulant, Its Effects, and Its Dangers
What the drug speed is, how it relates to amphetamine and methamphetamine, the effects people seek and the comedown that follows, the short-term and long-term dangers, and why it is so addictive.
Clinically reviewed by Dr. Ponlawat Pitsuwan, Physician and Addiction Medicine Specialist, Phuket Island Rehab.
Speed is a common street name for amphetamine, a powerful stimulant drug, usually sold as a paste or powder that is swallowed, snorted, or injected. The name is sometimes also used for methamphetamine, a stronger, more dangerous relative. Speed works by flooding the brain with the stimulating chemicals dopamine and noradrenaline, producing increased energy, alertness, confidence, talkativeness, and euphoria, along with reduced appetite and the ability to stay awake for long periods. These effects come at a cost: a racing heart, raised blood pressure and temperature, anxiety, and the risk of heart problems, while the comedown brings exhaustion, low mood, and irritability. Speed is highly addictive, leading to tolerance, dependence, and a destructive binge-and-crash cycle, and long-term use damages the heart, brain, and mental health, with a real risk of psychosis. There is no medication that reverses stimulant addiction, but it is treatable, and the brain recovers with sustained abstinence.
What speed is
Speed is a common street name for amphetamine, a powerful stimulant drug that speeds up the messages between the brain and the body, which is where the name comes from. It is usually sold illicitly as a white, grey, or off-white powder or paste, sometimes called base, and it is swallowed, snorted, rubbed on the gums, or injected. Amphetamine is the same basic drug found, in pharmaceutical form, in prescription stimulants used for ADHD, but street speed is unregulated, of unknown purity and strength, and often heavily cut with other substances, which makes it considerably more dangerous than a measured medical dose.
It is worth clearing up a common confusion: the word speed is used a little differently in different places. Most often it refers to amphetamine, but in some regions speed is used to mean methamphetamine, a closely related but stronger and more dangerous stimulant, sometimes called crystal meth in its smokable form. Whether the speed in question is amphetamine or methamphetamine, both are powerful, addictive stimulants from the same family, with similar effects and dangers, though methamphetamine tends to be more potent and more damaging. This article covers amphetamine-type speed, with the understanding that the risks apply across the group.
The effects people seek
Speed produces its effects by flooding the brain with dopamine and noradrenaline, the chemicals involved in reward, energy, and alertness. People who use it describe a rush of increased energy, wakefulness, confidence, and talkativeness, a feeling of being switched on and able to keep going, reduced need for sleep, and a suppressed appetite. At higher doses there is euphoria, a sense of well-being and excitement. These effects are why people use speed to party, to stay awake, to work or study, or to lose weight, and they typically last several hours, longer than the brief high of cocaine.
The trouble is that these sought-after effects are inseparable from the drug’s dangers, and they are paid for afterward. Even during the high, speed causes a racing heart, raised blood pressure, a higher body temperature, jaw clenching, restlessness, and often anxiety and agitation, and as the dose rises, the pleasant effects give way to paranoia, irritability, and a wired, uncomfortable state. The energy and confidence are not free; they are the brain being driven hard, and the bill comes due in the comedown and, with continued use, in lasting harm. Understanding speed means understanding both sides of it.
The comedown and the crash
After the effects of speed wear off comes the comedown, sometimes called the crash, and it is a defining and unpleasant part of using the drug. As the flood of brain chemicals is depleted, the person is left feeling exhausted but often unable to sleep, low, anxious, irritable, and flat, with strong cravings to use again to escape the bad feelings. After a binge of repeated use over a day or more, this crash can be severe, with deep fatigue, ravenous hunger, and a heavy, depressed low that can last for days and includes a real risk of suicidal thinking.
This crash drives the destructive pattern at the heart of stimulant use. Because using again temporarily relieves the comedown, people often redose repeatedly, chasing the fading high or just trying to avoid the crash, in a binge that can go on for days without proper sleep or food. This binge-and-crash cycle is exhausting and damaging to the body and mind, and it is a major part of how speed traps people and how it does its harm. The comedown is not a separate event from the high; it is the other half of the same coin.
| Phase | What happens |
|---|---|
| The high | Energy, alertness, confidence, euphoria, reduced appetite and sleep |
| During use | Racing heart, high blood pressure, jaw clenching, anxiety, agitation |
| Higher doses | Paranoia, irritability, a wired uncomfortable state |
| The comedown / crash | Exhaustion, low mood, anxiety, irritability, strong cravings |
| After a binge | Severe depression, deep fatigue, hunger, suicidal thinking risk |
The dangers of speed
Speed is dangerous in both the short and long term. In the short term, the strain it puts on the cardiovascular system can cause a dangerously fast or irregular heartbeat, very high blood pressure, and overheating, and it can trigger a heart attack, stroke, or seizures even in young, healthy people, particularly at high doses, with physical exertion, or in hot environments. A stimulant overdose, with chest pain, a racing heart, severe agitation, seizures, or dangerous overheating, is a real risk, and unlike an opioid overdose there is no antidote.
With repeated, long-term use, the harm accumulates. Speed damages the heart and blood vessels, raising the long-term risk of heart disease. It causes severe weight loss and malnutrition through appetite suppression, damages teeth and skin, and exhausts the body through repeated sleep deprivation. Most seriously, heavy or prolonged use takes a profound toll on mental health: chronic anxiety, depression, and, importantly, amphetamine psychosis, a state of paranoia, delusions, and hallucinations that can resemble a serious mental illness and that becomes more likely with heavy use. Injecting speed adds the risks of infections and bloodborne viruses.
Why speed is so addictive
Speed is highly addictive, and the reason lies in how it affects the brain’s reward system. By flooding the brain with dopamine, it produces a powerful reward that the brain learns to want, and with repeated use the brain adapts: it produces less of its own dopamine and becomes less responsive, so the person needs the drug to feel normal and gets little pleasure from anything else, while craving it intensely. This is tolerance, where more is needed for the same effect, and dependence, where the drug is needed to function, and together with the misery of the comedown they drive compulsive, escalating use.
The binge-and-crash cycle accelerates this, because the relief of using again to escape the crash is itself powerfully reinforcing. Over time, the person’s life narrows around the drug, and stopping becomes difficult both because of the cravings and because the depleted brain makes early abstinence feel flat and bleak. This is not weakness; it is the predictable result of what amphetamine does to the brain. The encouraging side is that the brain’s reward system, though disrupted by heavy use, does heal substantially over months of sustained abstinence, which is the basis for recovery.
When substance use has become more than occasional
Speed use rarely stays isolated. Many people who use it also drink heavily, often to take the edge off the stimulation or to manage the comedown, and others use sedatives or opioids to come down, all of which add their own dangers. Alcohol use disorder commonly sits alongside stimulant addiction, each feeding the other, and using a depressant to manage a stimulant, or the reverse, builds a dangerous cycle that is hard on the heart and the mind. Effective treatment has to address the whole pattern of substance use, not just the speed.
If you or someone you love is using speed, caught in the binge-and-crash cycle, or combining it with alcohol or other drugs, it is worth seeking help. A stimulant overdose and amphetamine psychosis are treated as emergencies rather than with a detox, but anyone who is also physically dependent on alcohol or benzodiazepines should not stop those suddenly, because that withdrawal can cause seizures, so a medically supervised detox is essential where they are involved. There is no medication that reverses stimulant addiction, but it is treatable with structured therapy and support, the brain heals with abstinence, and people recover from it. Help is available and recovery is realistic.
Summary
Speed is a common street name for amphetamine, a powerful stimulant usually sold as a paste or powder that is swallowed, snorted, or injected, and the name is sometimes also used for the stronger, more dangerous methamphetamine. It works by flooding the brain with dopamine and noradrenaline, producing increased energy, alertness, confidence, and euphoria, along with reduced appetite and the ability to stay awake, but at the cost of a racing heart, raised blood pressure and temperature, anxiety, and the risk of heart problems, followed by an exhausting, depressed comedown. Speed is highly addictive, driving tolerance, dependence, and a destructive binge-and-crash cycle, and long-term use damages the heart, brain, and mental health, with a real risk of psychosis. There is no medication that reverses stimulant addiction, but it is treatable, and the brain recovers with sustained abstinence.
As Dr. Ponlawat Pitsuwan, addiction medicine specialist at Phuket Island Rehab, puts it, “People come to speed for the energy and the confidence, and what they do not factor in is the bill. Every hour of feeling switched on is borrowed, and the crash, the paranoia, the worn-out heart, the depression, is the repayment with interest. The good news I can offer is that the brain is not broken forever. Stop the drug, get support through the bleak early weeks, and the reward system genuinely heals.”
Frequently asked questions
What is the drug speed?
Speed is a common street name for amphetamine, a powerful stimulant that speeds up the messages between brain and body. It is usually sold as a white or off-white powder or paste and is swallowed, snorted, rubbed on the gums, or injected. In some regions the word speed is used for methamphetamine, a stronger relative. Both are addictive stimulants from the same family with similar effects and dangers.
What does speed feel like?
Speed produces increased energy, wakefulness, confidence, talkativeness, and at higher doses euphoria, along with reduced appetite and the ability to stay awake for long periods, typically for several hours. These come with a racing heart, raised blood pressure, jaw clenching, restlessness, and often anxiety, and as the dose rises the pleasant effects give way to paranoia and a wired, uncomfortable state. The high is followed by an unpleasant comedown.
Is speed the same as meth?
Speed usually refers to amphetamine, while meth is methamphetamine, a closely related but stronger and more dangerous stimulant, though in some places the word speed is used for methamphetamine too. Both are powerful, addictive stimulants from the same family with similar effects and dangers, but methamphetamine tends to be more potent and more damaging, particularly in its smokable crystal form.
What is a speed comedown like?
As speed wears off, the comedown or crash brings exhaustion, often with an inability to sleep, low mood, anxiety, irritability, flatness, and strong cravings to use again. After a binge of repeated use, the crash can be severe, with deep fatigue, ravenous hunger, and a heavy depression that can last for days and carries a real risk of suicidal thinking. The crash drives the binge-and-crash cycle that traps people.
Is speed dangerous?
Yes. In the short term, speed can cause a dangerous heartbeat, very high blood pressure, overheating, and can trigger a heart attack, stroke, or seizures even in young, healthy people, with no antidote for a stimulant overdose. Long-term use damages the heart, causes severe weight loss, and seriously harms mental health, including amphetamine psychosis with paranoia and hallucinations. Injecting adds infection risks, and mixing speed with other drugs increases the dangers.
Is speed addictive, and can addiction be treated?
Speed is highly addictive, because it floods the brain’s reward system with dopamine, leading to tolerance, dependence, and a compulsive binge-and-crash cycle. There is no medication that reverses stimulant addiction, but it is treatable with structured behavioural therapy, support through the difficult early weeks, and treatment of any co-occurring mental health conditions. The brain’s reward system heals substantially with sustained abstinence, and people do recover from speed addiction.
Sources
National Institute on Drug Abuse (NIDA). Prescription Stimulants and Methamphetamine. https://nida.nih.gov/research-topics/methamphetamine
National Health Service (NHS). Speed (Amphetamine). https://www.nhs.uk/conditions/recreational-drugs-misuse/
Substance Abuse and Mental Health Services Administration (SAMHSA). Stimulants. https://www.samhsa.gov/
National Institute on Drug Abuse (NIDA). Prescription Stimulants DrugFacts. https://nida.nih.gov/publications/drugfacts/prescription-stimulants
American Heart Association. Illegal Drugs and Heart Disease. https://www.heart.org/
World Health Organization (WHO). Amphetamine-Type Stimulants. https://www.who.int/
What is speed — key entities and related terms
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