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Guide · ADHD medication

Dexamphetamine: what it is, what it does and the risks

Dexamfetamine, often searched as dexamphetamine, is a short-acting stimulant medicine used in Australia for ADHD and narcolepsy. This guide covers how it works, what the research shows, its side effects and why it is tightly controlled.

Updated 25 September 2026 · About 8 minutes to read · All guides

In short

  • Dexamfetamine, often searched as dexamphetamine and nicknamed dexies, is a stimulant medicine approved in Australia for ADHD and narcolepsy.
  • The tablets are immediate release: a dose lasts about 4 to 6 hours, so it is usually taken once or twice a day, early in the day.
  • In short-term trials, amphetamine medicines reduced ADHD symptoms more than placebo, but more people stopped taking them because of side effects.
  • Common side effects include poor appetite, trouble sleeping, headache and a faster heart rate. It is not suitable for everyone, including people with some heart conditions.
  • It is a Schedule 8 controlled medicine. Taking someone else’s is illegal, and research in people without ADHD finds modest effects on thinking at best.

What dexamfetamine is and what it is approved for

Dexamfetamine (dexamfetamine sulfate) is a stimulant medicine from the amphetamine group. Dexamfetamine and dexamphetamine are two spellings of the same medicine, and both appear in Australian product names. “Dexies” is a common street name.

In Australia it is approved for two conditions:

  • ADHD. The TGA registration covers ADHD from age 3 to 17. Healthdirect’s listing uses the wording “hyperkinetic behaviour disorders in children”, another name for ADHD in children. Prescribing it for adults with ADHD falls outside that age range, which is called off-label use.
  • Narcolepsy, a sleep disorder with recurring attacks of irresistible daytime sleepiness.

Healthdirect lists the brands available in Australia. The consumer medicine information (CMI) is the official plain-language leaflet.

Dexamfetamine is closely related to lisdexamfetamine (Vyvanse), which the body converts into dexamfetamine in the blood. The lisdexamfetamine (Vyvanse) guide covers that medicine.

How it works and how it is taken

Stimulant ADHD medicines change how chemical messengers in the brain work, mainly dopamine and noradrenaline. For people with ADHD this can improve attention, impulsiveness and behaviour. Dexamfetamine also increases alertness and wakefulness, which is why it is used for narcolepsy.

The tablets are immediate release. Australian Prescriber lists a dose as lasting about 4 to 6 hours, taken once or twice a day. Longer-acting stimulants, such as lisdexamfetamine and some methylphenidate products, cover more of the day from one morning dose.

In general terms, the CMI describes:

  • starting on a low dose and increasing it in small steps, usually a week apart
  • taking the day’s amount as one or two doses
  • taking it early in the day, because later doses can cause insomnia.

What the evidence shows

A 2018 network meta-analysis by Cortese and colleagues compared ADHD medicines across 133 double-blind randomised trials. At around 12 weeks, amphetamines reduced clinician-rated ADHD symptoms more than placebo, in children and teenagers and in adults.

They were also harder to tolerate. The odds of dropping out because of side effects were about 2.3 times higher than on placebo in children and 3.3 times higher in adults. Weighing both, the authors named methylphenidate for children and teenagers, and amphetamines for adults, as the preferred first choices for short-term treatment.

Some limits matter:

  • The review grouped all amphetamines together, including lisdexamfetamine, so its results are not specific to dexamfetamine tablets.
  • It answers short-term questions only. The authors pointed to how few trials followed people beyond 12 weeks.
  • Not everyone responds. Australian Prescriber estimates that about 70% of children respond to stimulant medicine.

Australia’s national ADHD guideline recommends stimulants first for children and teenagers who need medication. Australian Prescriber notes that methylphenidate remains the recommended first choice for children, because it was better tolerated and teachers rated classroom performance higher, although clinicians rated amphetamines slightly more effective.

Side effects and who should not take it

The CMI lists nausea, headache, dizziness, mood changes, trouble sleeping, a fast heartbeat, restlessness, loss of appetite and weight loss among the more common side effects. Australian Prescriber names appetite loss, irritability, insomnia, stomach pain and headache as the most common with stimulants generally.

  • Heart and blood pressure. Stimulants can raise blood pressure and heart rate. Sudden death has been reported in children with heart abnormalities taking stimulants, and the CMI says blood pressure and pulse should be checked regularly. Australian Prescriber recommends measuring height, weight, heart rate and blood pressure at least every six months.
  • Growth. Children’s growth is monitored, because consistent long-term stimulant use may reduce growth and adult height.
  • Mood and mental health. The CMI warns of possible worsening aggression, depression and suicidal thoughts. A 2024 US case-control study of people aged 16 to 35 found that past-month prescription amphetamine use was linked with higher odds of a first episode of psychosis or mania, and doses above 30 mg a day (in dextroamphetamine terms) with about five times the odds. It was observational and used hospital patients as controls, so it cannot prove cause.

The CMI says dexamfetamine should not be taken by people with an allergy to amphetamines, heart disease, moderate to severe high blood pressure, glaucoma, an overactive thyroid, severe depression or suicidal thoughts, a history of drug dependence or alcohol misuse, or within 14 days of taking an MAOI antidepressant. It also lists tics, Tourette’s syndrome and anxiety. Australian Prescriber notes that stimulants can worsen tics and anxiety, but that having them does not by itself rule out medication. That is a judgement for the prescriber.

Get urgent medical help for chest pain, shortness of breath, an irregular heartbeat, a seizure, vision problems, sudden weakness, a severe headache, or thoughts of self-harm.

Schedule 8 controls, misuse and diversion

Dexamfetamine is a Schedule 8 controlled drug, which means special restrictions apply to how it is prescribed and supplied:

  • Prescribers generally need approval from their state or territory, and the rules differ. In NSW a script needs an NSW Health approval number before a pharmacist can dispense it. Victoria requires a permit, with exemptions for some specialists. Western Australia allows one stimulant prescriber per patient at a time.
  • Real-time prescription monitoring tracks controlled medicines in every state and territory, and it is mandatory in Victoria and Queensland.
  • Healthdirect notes that prescriptions must be held at the pharmacy.

The CMI states that amphetamines have a high potential for abuse and misuse. Chronic misuse can lead to marked tolerance, psychological dependence and addiction, and misuse can cause overdose and death. Stopping suddenly after regular use can bring on depression or extreme tiredness. The CMI advises storing the tablets somewhere safe, preferably locked.

Diversion means a prescribed medicine ending up with someone it was not prescribed for, whether it is given, shared or sold. Healthdirect states that sharing ADHD medicine or taking someone else’s is unsafe and illegal in Australia. In Western Australia, prescribers must notify the health department if they stop treatment because of diversion or misuse.

What do dexies do to someone without ADHD?

Taking dexamfetamine prescribed for someone else is illegal and unsafe. It also skips the checks a prescriber makes first, such as heart health, blood pressure, mental health history and other medicines.

Dexamfetamine acts as a stimulant in anyone who takes it. The Alcohol and Drug Foundation notes that it is used without a prescription to feel more alert or to get high. The same side effects apply, and the comedown can bring exhaustion, restless sleep, irritability and anxiety. Non-prescribed use carries a higher risk of psychotic symptoms, and alcohol with dexamfetamine can mask how drunk someone is.

The research does not support the idea of a “smart drug”:

  • A 2015 meta-analysis of 48 studies with 1,409 healthy participants found small improvements in inhibitory control and short-term memory from amphetamine and methylphenidate, a medium effect on delayed memory, and small working-memory effects in only one of two analyses. Because of signs of publication bias, the authors concluded the effects are probably modest overall.
  • A 2023 double-blind study gave 40 healthy people dextroamphetamine, methylphenidate, modafinil and a placebo in separate sessions before a complex problem-solving task. On the drugs they worked harder and for longer, but the quality of their solutions fell, and above-average performers often ended up below average.

Feeling more driven is not the same as doing better work. If someone may have taken too much, call the Poisons Information Centre on 13 11 26, or 000 in an emergency.

Questions to ask the prescriber

  • Why this medicine, and would a shorter- or longer-acting one suit the day better?
  • How will we know it is working, and when will we review it?
  • Which side effects are expected early, and which need a call straight away?
  • What heart, blood pressure, growth and weight checks will happen, and how often?
  • Does it interact with other medicines, supplements or alcohol?
  • What are the rules for storing it, travelling with it, or changing prescribers?
  • What should happen if a dose is missed, or if we want to stop?

This guide is general information, not medical advice. Decisions about starting, changing or stopping medication are made with the prescribing doctor.

Questions people ask

Is dexamphetamine the same as dexamfetamine?

Yes. They are two spellings of the same medicine, dexamfetamine sulfate. Both appear in Australian product names, for example Aspen Dexamfetamine and Dexamphetamine Sulfate (Sigma). “Dexies” is a common street name for it.

How long does dexamphetamine last?

The tablets are immediate release. Australian Prescriber lists a dose as lasting about 4 to 6 hours, so it is usually taken once or twice a day, early in the day, because later doses can cause insomnia.

What do dexies do to someone without ADHD?

They act as a stimulant, with the same side effects, such as a faster heartbeat, poor appetite and trouble sleeping, often followed by a comedown. Research in healthy people finds modest effects on thinking at best. Taking someone else’s prescription is illegal in Australia and skips the health checks done before prescribing.

Is dexamphetamine a Schedule 8 drug?

Yes. Dexamfetamine is a Schedule 8 controlled drug in Australia, as are methylphenidate and lisdexamfetamine. Prescribers generally need approval from their state or territory, prescribing is tracked through real-time prescription monitoring, and the rules differ between states.

Can adults take dexamphetamine for ADHD?

It can be prescribed for adults, but the TGA registration for ADHD covers ages 3 to 17, so adult use for ADHD is off-label. Whether it suits a particular adult is a decision for the prescriber.

Is dexamphetamine the same as Vyvanse?

No, but they are closely related. Vyvanse contains lisdexamfetamine, which is converted in the blood into dexamfetamine. Australian Prescriber lists lisdexamfetamine as a once-daily medicine lasting about 6 to 12 hours, compared with about 4 to 6 hours for a dexamfetamine tablet.

Related

ADHD medication · Lisdexamfetamine (Vyvanse) · Ritalin and Concerta · All guides

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