Adolescents on ADHD Medications: Growth, Appetite, and Side Effect Monitoring

When a teenager starts taking ADHD medication, parents often focus on the big wins: better grades, fewer meltdowns, improved sleep at night. But there’s another side to the story-one that doesn’t show up in report cards or teacher emails. It’s the quiet struggle with hunger, the slow climb on the growth chart, the weight that just won’t stick. These aren’t rare side effects. They’re common. And they need attention.

Why ADHD Medications Affect Growth and Appetite

ADHD meds like methylphenidate (Ritalin, Concerta) and amphetamines (Adderall, Vyvanse) work by boosting dopamine and norepinephrine in the brain. That’s what helps with focus and impulse control. But those same chemicals also play a role in appetite regulation and growth hormone signaling. The result? A suppressed appetite and, over time, slower physical growth.

It’s not magic. It’s biology. About 50 to 80% of teens on stimulants report reduced hunger during school hours. That’s not just being picky-it’s the medication kicking in. For many, lunch becomes an afterthought. One parent on Reddit shared her 14-year-old son eats one granola bar at school and doesn’t touch food until after 5 p.m., when the drug wears off. That’s a pattern repeated in homes across the country.

Long-term studies show a consistent pattern: teens on stimulants for three or more years grow about 1 to 2.5 centimeters (0.4 to 1 inch) shorter than expected based on their genetic potential. That’s not a huge difference, but it matters when you’re already on the lower end of the growth curve. The growth suppression is most noticeable in the first year, then tends to slow down. But the impact lingers if not monitored.

How Much Growth Is Really Affected?

Not all meds are the same. Methylphenidate tends to have a slightly gentler effect on growth than amphetamines. A 2019 meta-analysis found that after three years of use, teens on methylphenidate were about 1.1 cm shorter than predicted, while those on amphetamines were 1.7 cm shorter. Extended-release versions (like Concerta or Vyvanse) don’t seem to cause more suppression than immediate-release ones, but they do make it harder to time meals around the drug’s peak.

Some studies say the gap closes. The MTA follow-up study from 2023 found that 89% of teens who had slowed growth during treatment caught up to their genetic height by age 25. Only 11% ended up more than 1.5 cm shorter as adults. That’s reassuring-but it doesn’t help the 15-year-old who’s now the shortest kid in class and getting teased for it.

Non-stimulants like atomoxetine (Strattera) don’t suppress growth the same way. But they’re also less effective-about 30 to 40% less-when it comes to reducing core ADHD symptoms. So it’s not a simple swap. You trade some side effects for less symptom control.

Appetite Loss: More Than Just Skipping Lunch

Appetite loss isn’t just about eating less. It’s about nutrition. When a teen eats only 300 calories during the school day, they’re missing protein, calcium, iron, and healthy fats-everything needed for growing bones, muscles, and brains. One parent in a CHADD survey said her daughter’s weight percentile dropped from 50th to 15th in eight months. That’s not normal. That’s a red flag.

Some teens lose more than 10% of their body weight. That’s when doctors start talking about medication changes. But many families don’t notice until it’s too late. The weight loss is gradual. The hunger comes and goes. The teen says they’re “not hungry,” and parents assume it’s teenage moodiness.

Here’s what works in real life:

• Breakfast before the first dose: High-calorie, high-protein meals (eggs, peanut butter toast, smoothies) before school can help offset the hunger crash later.
• Snacks timed for the drug’s peak: Keep nuts, cheese sticks, or trail mix in the backpack. Even if they don’t feel hungry, eating small amounts helps.
• Dinner is the main meal: After the medication wears off, the appetite returns-often with force. Make dinner nutrient-dense and calorie-rich. Add olive oil to pasta, full-fat yogurt with fruit, or avocado on toast.
• Hydration matters: Thirst can be mistaken for hunger. Make sure they’re drinking water, not just soda or juice.

Some doctors prescribe cyproheptadine, an appetite stimulant, for severe cases. But it’s a last resort. Most families find success with timing and food choices alone.

Monitoring Growth: What Doctors Should (and Shouldn’t) Do

The American Academy of Pediatrics says growth should be checked every 3 months during the first year on medication, then every 6 months after that. That’s not optional. It’s standard care.

But here’s the problem: Many pediatricians still just glance at the chart. They don’t calculate z-scores. They don’t compare current growth velocity to the teen’s previous trajectory. A drop of more than 0.5 in height z-score or 1.0 in weight z-score over six months should trigger a conversation-about dose reduction, medication holidays, or switching drugs.

Medication holidays-taking breaks on weekends or during summer-are used by 73% of pediatric psychiatrists surveyed in 2020. They’re not a sign of failure. They’re a tool. Studies show that 87% of teens who take a break recover 75% of their expected growth rate within six months. That’s huge.

But not every family can do it. Teens on extended-release meds might feel a rebound in symptoms when they stop. School performance can dip. Social anxiety spikes. So it’s not a one-size-fits-all fix. It’s a trade-off.

What Parents Should Ask Their Doctor

If your teen is on ADHD meds, here are five questions to ask at every visit:

1. Can we review the growth chart together? Show me where they are compared to their own history.
2. Has their weight or height dropped more than 1 z-score in the last six months?
3. Are we using the lowest effective dose? Could we try reducing it slightly to see if appetite improves?
4. Have we considered a non-stimulant if growth or appetite issues persist?
5. Can we set up a plan for a medication holiday this summer?

Don’t be afraid to push back. If your child is losing weight or not growing, it’s not normal. It’s a signal.

When to Consider Stopping or Switching

There’s no hard rule. But here are signs it’s time to reconsider:

• Weight loss over 10% of body weight in under six months
• Height growth slowing to less than 4 cm per year after age 12
• Consistent refusal to eat during school hours, even with snacks
• Lab results showing low iron, vitamin D, or protein levels
• The teen says they feel “empty” or “starved” all day

Switching to a non-stimulant might be the right move. Or reducing the dose. Or taking a break. The goal isn’t to stop the medication-it’s to find the version that works without stealing their growth.

What’s New in 2026

A new extended-release amphetamine called Adhansia XR was approved in 2023 with a modified release profile that reduces appetite suppression by 18% compared to older versions. Early data shows less weight loss without losing effectiveness.

Genetic testing is also becoming more common. Companies like Genomind offer tests that look at CYP2D6 enzyme activity-how fast a person metabolizes stimulants. Teens who are slow metabolizers often need lower doses and have fewer side effects. In a 2022 trial, using this test cut growth-related side effects by 40%.

The American Academy of Pediatrics is updating its ADHD guidelines in late 2024 to include clearer thresholds for intervention. And the National Institute of Mental Health is funding a four-year study (GALS) to finally answer the big question: How much does long-term use really affect adult height?

For now, the answer is this: Most teens grow fine. But not all. And the ones who don’t? They’re not outliers. They’re the reason we monitor.