ADHD medication: types, side effects and risks

Summary: ADHD medication can make a real difference to focus, impulse control, and day-to-day life. There are two main types: stimulants and non-stimulants. You and your clinician will figure out which works best for you. As with any medication, there are risks and side effects – and we’ll keep a close eye on those throughout your treatment. 

• ADHD medication: introduction

• Types of ADHD medication

• Risks and side effects

• FAQs 

This article only applies to patients diagnosed with ADHD, or ADHD together with other conditions like autism – where treatment is often different.

ADHD medication works by boosting the chemical signals in your brain. This can help you to focus, control impulses, and manage everyday tasks. 

For lots of people, this can be life changing. That said, medication affects everyone differently and is just one part of ADHD treatment, alongside options like Cognitive Behavioural Therapy (CBT) or coaching. If medication is right for you, we’ll help you find the right type of medication and dosage. 

Explore our Help Centre for information on the titration process and how to manage medication and prescriptions. 

There are two types of ADHD medication: stimulants and non-stimulants. As you go through titration, your clinician will recommend the best fit, based on your medical history and any preferences you have. 

• Stimulant medications
  Stimulants are the most commonly prescribed medication for ADHD. They’re usually the first option we try. They work by increasing levels of dopamine and noradrenaline in the brain. This helps to improve attention and self-control. Available stimulants include: 

• Methylphenidate (e.g. Concerta)
  This is often the first medication we prescribe for ADHD. It comes in two types: short-acting, which lasts a few hours, and long-acting, which releases slowly throughout the day. 

• Dexamfetamine (Amfexa)
  We often try this if methylphenidate hasn't worked. Dexamfetamine is also short-acting and usually starts to work within a few hours. 

• Lisdexamfetamine (Elvanse)
  This is a widely used long-acting ADHD medication. Your body converts it into dextroamphetamine, a stimulant that acts on the central nervous system. 

• Non-stimulant medications
  We recommend non-stimulants when stimulants aren't the best choice – for example, if you've experienced unwanted side effects. Available non-stimulants include: 

• Atomoxetine (Strattera)
  This medication helps improve focus and reduce impulsivity. It's non-addictive and tends to work well for people who don't get on with stimulants. You might’ve heard of “atomoxetine” by its original brand name ‘Strattera’. 

• Guanfacine (Intuniv)
  Guanfacine can help with impulse control and hyperactivity – though it's less commonly prescribed as it is only licensed in the UK for those under the age of 18. Please be aware: NHS GPs can’t accept guanfacine under shared care. If you have a prescription for guanfacine, you’ll need to get your medication privately.  

ADHD medication is safe and effective for most people, but like all medications, there are potential side effects, and each person's experience is different. 

It’s worth keeping a note of how you’re getting on with your medication and bringing any questions or concerns to your appointments. Your clinician will help you manage any issues while making sure you're getting the most out of your medication. 

• Weight loss
  ADHD medication can reduce your appetite, which can sometimes lead to weight loss. It helps to eat a good meal before taking your medication. We’ll also keep an eye on your weight at appointments. 

• Trouble sleeping
  Stimulant medications can interfere with sleep if they’re taken late in the day. Taking your medication in the morning or early afternoon should help with this. 

• Increased blood pressure and pulse rate
  Some medications can cause a slight increase in blood pressure and heart rate. We'll check your readings at appointments and adjust your treatment if needed. 

• Mental health changes
  In rare cases, ADHD medication can affect your mood or anxiety levels. If you notice anything significant, we recommend that you stop taking your medication immediately and contact us or your GP. 

  If the changes aren’t significant, and it’s safe to wait, you can stay on your medication and raise this at your next appointment. We’re not a crisis service, but if you’re struggling, there are ways to get help today. If you’re in crisis or feel you may be at risk of harming yourself, please call 999 or go to your nearest A&E.  

• Heart problems
  Although rare, stimulant medications can increase the risk of heart-related issues – particularly if you have a pre-existing condition. We'll review your full medical history before treatment begins and might request a heart scan (ECG) or other tests, if needed.

• Serotonin syndrome
  Serotonin syndrome is a rare but serious condition. It’s caused by excess serotonin in the brain. The risk from ADHD medication is low, but rises when combined with other medications or substances like antidepressants, pain medications, or recreational drugs. Symptoms tend to come on within hours and can include: 

  • Confusion or agitation

  • Rapid heart rate

  • Muscle twitching

  • Sweating or nausea

  • Severe symptoms – like high fever, seizures or loss of consciousness – need immediate medical attention. Call 999 or go to A&E. 

For a full list of medications and substances that increase the risk, see taking ADHD medication safely. 

Dependency or misuse Stimulant medications can be habit-forming, but this risk is low if you take them as prescribed. Always follow your clinician's advice on how and when to take them. 

If you experience severe side effects – like chest pain, shortness of breath, or a sudden change in mood – stop taking your medication straight away. Go to your nearest hospital or contact your GP.

How will my clinician decide which medication is right for me? 

Your clinician will consider your medical history, any other health conditions, and how you respond to treatment. It may take a few adjustments to find the right fit – that's what the titration process is for. 

What if the first medication I try doesn't work? 

This is common. If a medication or dose isn't right for you, your clinician will adjust your treatment. You may try a different dose or switch to a different medication. 

Can I take ADHD medication if I have another health condition? 

Your clinician will review your full medical history before prescribing. They'll factor in any other conditions you have when recommending a medication.