Lisdexamfetamine (LDX)

A simple guide for people with ADHD

What is it?

• Lisdexamfetamine (LDX) is a once-daily stimulant used to treat ADHD in children (6+) and adults.

• It’s a pro-drug of dexamfetamine: after you swallow it, your red blood cells convert it into the active medicine. This slow conversion gives an even effect through the day, so one morning dose is usually enough.

• It can work well for people who didn’t get on with methylphenidate.

UK note: Some “Elvanse Adult” capsule inks contain propylene glycol. A few people are sensitive to this—tell your pharmacist if you’ve reacted to it before.

How does it help ADHD?

• ADHD is linked to lower activity of dopamine and noradrenaline in brain networks for focus, self-control, and reward.

• LDX increases these chemicals (by becoming dexamfetamine), which strengthens signalling, helping you concentrate, sit with tasks, and reduce impulsivity.

• It can also improve quality of life when used alongside educational, psychological, and social support.

Who is it for?

• Children (6+) and adults with ADHD symptoms, including adults whose symptoms started in childhood but were never treated.

• LDX is also used in some countries for binge-eating disorder and narcolepsy, but these uses are off-label in the UK.

Doses and timing

• Start: usually 30 mg each morning (sometimes 20 mg).

• Titration: increase by 10–20 mg weekly to find your “Goldilocks” dose (best effect, least side effects).

• Typical max: 70 mg once daily (some people may need more under specialist care).

• Onset: starts to work in 1–2 hours.

• Duration: effects last about 13–14 hours.

• PMS tip (females): some notice symptoms worsen pre-menstrually; a 30–50% temporary dose increase can help (only with prescriber advice).

How to take it

• Take in the morning, with or after breakfast. Avoid afternoon/evening doses (may keep you awake).

• Swallow capsules whole with water while sitting or standing.

• If swallowing is hard: open the capsule and mix the powder in water, orange juice, or sprinkle on yoghurt. Break up any lumps, stir well, and drink/eat straight away (don’t store). A faint residue on the glass is normal.

How long will I need it?

• Many people take LDX for months to years.

• Your clinician may suggest “drug holidays” (e.g., weekends or school holidays) or yearly reviews to check ongoing need.

• If there’s no meaningful benefit after ~4 weeks at the right dose, your prescriber will usually switch or stop.

Can I stop suddenly?

• Low doses: often fine to stop without taper.

• Higher doses: best to reduce over a few weeks to avoid “rebound” (tiredness, increased appetite, low mood, restlessness).

• If you stop and feel rough, restarting (under advice) usually settles this.

Missed or double dose

Missed dose:

• If you remember by late morning, take it then. Otherwise skip and take your usual dose the next morning.

• Do not double up.

Accidental double dose (not a large overdose):

• Most people feel worst in the first ~5 hours, improving by ~12 hours.

• Possible symptoms: headache, tummy pain, agitation, poor sleep.

• Avoid driving, alcohol, and heavy exercise for 24–36 hours.

• If you have heart disease, pregnancy/breastfeeding, diabetes, kidney issues, are very sensitive to meds, or feel unwell (fast breathing, sweating, panic, severe agitation) → seek medical advice.

• In the UK, contact your prescriber, GP, or NHS 111. For severe symptoms, 999/A&E.

Is it addictive?

• In adults, any stimulant can be misused, but LDX’s slow conversion means no quick “buzz,” so abuse potential is lower than immediate-release amphetamines.

• In children, addiction appears unlikely.

• Large studies show treatment for ADHD does not increase later substance misuse; it may reduce self-medication in some people.

Common side effects

Usually dose-related and often ease with time or dose tweaks:

• Reduced appetite / weight loss

• Difficulty sleeping (if taken late), nervousness, restlessness

• Dry mouth, headache, tummy pain, nausea

• Faster heartbeat / slight blood pressure rise

Less common but important – contact your prescriber promptly if:

• Persistent insomnia, mood swings/irritability, tics, or aggression

• Marked palpitations, chest pain, fainting, or sustained high BP

• Raynaud’s-type circulation changes (painful, pale/blue fingers or toes)

• New or worsening anxiety, or concerning mood changes

Urgent help (A&E/999):

• Severe chest pain, collapse/fainting, seizures, signs of serotonin syndrome (fever, sweating, shivers, confusion, muscle jerks, fast heartbeat), or allergic reaction (wheezing, facial swelling, widespread rash).

Interactions & cautions

Tell your clinician/pharmacist about all medicines, vitamins, and herbal products. Be careful with:

• MAOIs (contraindicated) or recent MAOI use

• Other stimulants or sympathomimetics (decongestants, some weight-loss or energy products)

• Some antidepressants and migraine triptans (serotonergic load → rare risk of serotonin syndrome)

• Acidifying/alkalinising agents (can alter amphetamine levels)

• Alcohol (can worsen side effects)

Health conditions needing extra care:

• Heart disease, structural heart problems, serious arrhythmias, or uncontrolled hypertension

• Glaucoma, hyperthyroidism, severe anxiety/agitation

• Pregnancy/breastfeeding: discuss risks/benefits and alternatives.

Alternatives if LDX doesn’t suit you

• Stimulants: methylphenidate (various formulations), dexamfetamine

• Non-stimulants: atomoxetine, guanfacine (children/adolescents), bupropion (off-label)

• Psychological/skills supports: coaching, CBT for ADHD, school or workplace adjustments

Quick tips for success

• Take in the morning, with food if you like.

• Track benefits and side effects (simple diary or app).

• Keep regular reviews with your prescriber; bring blood pressure/weight if monitored.

• Pair medicine with sleep, nutrition, routines, exercise, and task-breakdown strategies.

Need help or worried?

• Contact your prescriber or GP.

• In the UK, call NHS 111 for urgent advice. For emergencies, call 999 or go to A&E.