Main Side Effects of Vyvanse (Lisdexamfetamine)
The most common side effects of Vyvanse include decreased appetite/anorexia, insomnia, dry mouth, irritability, headache, upper abdominal pain, nausea, weight loss, and anxiety, with appetite suppression and sleep disturbances being the most frequently reported. 1
Most Frequent Side Effects (≥5% incidence)
In Children and Adolescents (Ages 6-17):
- Decreased appetite/anorexia (34% in ages 13-17) 1
- Insomnia (13% in ages 13-17) 1
- Weight loss (9% in ages 13-17) 1
- Upper abdominal pain 1
- Irritability 1
- Vomiting 1
In Adults:
- Decreased appetite (27%) 1
- Insomnia (27%) 1
- Dry mouth (26%) 1
- Diarrhea (7%) 1
- Nausea (7%) 1
- Anxiety (6%) 1
- Anorexia (5%) 1
Additional Common Side Effects (2-5% incidence)
- Feeling jittery (4% in adults) 1
- Agitation (3% in adults) 1
- Increased blood pressure (3% in adults) 1
- Hyperhidrosis/sweating (3% in adults) 2, 1
- Restlessness (3% in adults) 1
- Increased heart rate (2% in adults) 1
- Tremor (2% in adults, 2% in adolescents) 1
- Palpitations (2% in adults and adolescents) 1
- Dizziness 1
- Headache 1, 3
Cardiovascular Effects
- Increased blood pressure and heart rate occur commonly and require monitoring 4
- Tachycardia was a leading cause of discontinuation (1% of adults) 1
- Hypertension led to discontinuation in 1% of adults 1
Sexual Side Effects (Adults)
Growth-Related Effects in Children
- Weight loss: Mean weight loss of 0.9-2.5 pounds after 4 weeks depending on dose (30-70 mg), compared to 1-pound weight gain with placebo 1
- Growth suppression: Consistently medicated pediatric patients showed slowing in growth rate with an age- and sex-normalized mean change from baseline in weight percentile of -13 over 12 months 1
- The American Academy of Child and Adolescent Psychiatry identifies appetite suppression as a primary adverse effect requiring monitoring with regular weighing at each visit 5, 4
Serious but Rare Side Effects
Peripheral Vasculopathy (Raynaud's Phenomenon):
- Fingers or toes may feel numb, cool, or painful 1
- Color changes from pale to blue to red 1
- Unexplained wounds on fingers or toes 1
Psychiatric Effects:
- New or worsening tics or Tourette's syndrome 1
- Psychotic symptoms or hallucinations (very rare) 5
- Mood disturbances 5
Serotonin Syndrome (when combined with serotonergic medications):
- Agitation, hallucinations, confusion 1
- Tachycardia, labile blood pressure 1
- Hyperthermia, diaphoresis 1
- Tremors, rigidity, myoclonus 1
- Nausea, vomiting, diarrhea 1
Discontinuation Rates Due to Side Effects
- Pediatric patients (ages 6-12): 8% discontinued vs. 0% on placebo 1
- Adolescents (ages 13-17): 3% discontinued vs. 1% on placebo 1
- Adults: 6% discontinued vs. 2% on placebo 1
The most common reasons for discontinuation were insomnia (2% in adults), tachycardia (1%), hypertension (1%), and decreased appetite (1% in adolescents) 1.
Management Strategies
- For appetite loss: Administer with meals and provide high-calorie snacks in the evening when medication effects have worn off 5, 4
- For insomnia: Take medication early in the morning (once daily dosing) 4, 1
- For most side effects: Dose reduction or timing adjustments typically alleviate symptoms 5, 4
- Monitor growth: Weigh children at each visit; height and weight should be checked regularly 5, 1
Important Clinical Context
Almost all stimulant-related side effects are mild, short-lived, and responsive to dose or timing adjustments 5. The American Academy of Child and Adolescent Psychiatry emphasizes that serious side effects are very rare and disappear when medication is reduced or discontinued 5. In real-world data, 48% of patients reported experiencing side effects, but only 21% considered them very or extremely bothersome 6. However, only 20% of patients mentioned side effects to their prescribing physicians, highlighting the importance of systematic assessment through specific questioning 5, 6.