How Vyvanse Is Different From Other Stimulants

Vyvanse is a long-acting stimulant medication used to treat ADHD in children and adults. It is approved by the FDA for use in kids with ADHD ages 6 and up.

There are two types of stimulant medications used for ADHD — those based on methylphenidate (Ritalin, for example), and those based on amphetamines (Adderall, for example). Some are short acting, and some are long acting.

Vyvanse is a long-acting amphetamine, but it is different from other ADHD medications because it is something called a prodrug — a kind of medication that isn’t active in your system until it is metabolized.

As a prodrug, Vyvanse has no therapeutic effect in its original form (lisdexamfetamine). After you take Vyvanse, in capsule or chewable form, it is converted in the body into an active drug. Enzymes in the bloodstream remove an amino acid called L-lysine from the Vyvanse molecule, converting it into dextroamphetamine, which is the active stimulant that affects the brain.

Once it is activated, Vyvanse affects the levels of two important brain chemicals, dopamine and norepinephrine, which help regulate attention, impulse control, and hyperactivity.

Because it is a prodrug, it has a more gradual onset than other stimulants, lasts longer, and has smoother control over ADHD symptoms, less likely to have spikes or crashes in the level of chemicals it stimulates in the brain.

As a prodrug, Vyvanse can affect children differently than other stimulants. Depending on the child’s needs, those differences can be advantageous.

Vyvanse works only after it’s been metabolized in the bloodstream, so it takes longer to kick in compared to other stimulants.

“When you take Adderall, usually in a half an hour or so, you’ll start to see the benefit of it,” explains Paul Mitrani, MD, PhD, a child and adolescent psychiatrist at the Child Mind Institute. “But when you take Vyvanse it can take from 90 minutes to two hours for it to be metabolized and start working.”

The delayed onset is good for kids who may have a longer commute to school, Dr. Mitrani adds, because you can time it for when they get to class, saving the benefits for when they are needed most.

Vyvanse can provide a steadier release of medication during the day, with fewer spikes in blood levels, minimizing the highs and lows some children experience with shorter-acting stimulants.

“Sometimes kids can feel like a stimulant is ‘too much’ when it hits their system or have a more abrupt drop off in benefits when it stops working which can result in them feeling ‘off’ or more dysregulated,” explains Dr. Mitrani. “In a lot of kids, Vyvanse tends to be smoother.”

Vyvanse is among the most long-lasting stimulants, remaining active for 10–14 hours.

“With Vyvanse, if you take it at 7:00 in the morning, it’s working by 9:00am, and it can be in your system till like 8:00 or 9:00 at night,” notes Dr. Mitrani.

Kids come off the medication less abruptly than they do with other stimulants, making them less likely to get irritable when the medication wears off (sometimes called “rebound”).

“Evenings can sometimes be smoother with Vyvanse, because it’s coming out of their system more gradually,” he adds. “You don’t necessarily have that crash you can have with other stimulants.”

Some children tolerate Vyvanse better than other amphetamines because of its slower onset and smoother, longer release. But that extended duration can result in other side effects.

The most common side effect associated with stimulants is appetite suppression, which can be most worrying with longest-acting medications, including Vyvanse.  

“If you’re taking just short-acting medications throughout the day, you have breaks where maybe your appetite comes back,” Dr. Mitrani notes. “But when your medication lasts for 10 or more hours, you have a big portion of the day where your appetite may be poor.”

Kids on Vyvanse are encouraged to eat a big breakfast before the effect of the medication kicks in. But depending on the child, that can be challenging, he adds. “Maybe they’re not a breakfast person, or they’re rushing out the door.” Another thing he notes is that sometimes kids with ADHD, when they’re not treated, just can’t sit for a meal. “Treating ADHD can help kids sit better for meals, but now their appetite is gone.”

Some kids are able to catch up with the calories they need in the evening, when the medicine wears off, and suddenly they are starving. But it’s important to monitor their weight, Dr. Mitrani says, to make sure the loss of appetite isn’t interfering with their growth and healthy development.

Difficulty falling or staying asleep is another common side effect of Vyvanse, as it is with other stimulants. Again, the length of time that the medication is active is a challenge — taking it by 7 or 8 in the morning can minimize trouble falling asleep in the evening. Creating a bedtime routine that avoids stimulation can also help. Another possibility is to talk to your doctor about lowering your child’s dose of Vyvanse.

“Sometimes kids complain that they don’t feel like themselves on the medication, that their personality is gone, or they feel dulled,” Dr. Mitrani notes. “That is a significant complaint, because we want kids to feel good and do well in school. We don’t want them to be robots. So, if that’s happening, it could be that the dose is too high. Or it could be that the medication isn’t right for them, so we need to adjust.”

When patients report an increase in anxiety, Dr. Mitrani tries to determine whether it’s situational — as in, they’re anxious about specific things — or more general.

“If it’s situational, it could be that the medicine is doing what it’s supposed to do, helping them focus better, but now they’re focusing on things like not getting invited to a party, or a scary movie they saw,” he explains. “If they are more anxious across the board, and feeling more edgy or panicky the entire day, then it suggests that the dose or medication is too much for them.”

As with any medication for ADHD, if your child is trying Vyvanse, it’s important to work with your doctor to find the right dose — one that balances effectiveness with minimizing side effects. And if it turns out that your child doesn’t tolerate it well at a level that’s effective, another medication may be a better fit.