Living with ADHD: Why stimulants are making you sleepy

If you've been prescribed stimulant medication for ADHD but end up feeling drowsy or low on energy, you're not alone in that experience. While these medications are designed to improve focus and alertness, some people feel the opposite effect not long after taking them.

This reaction can be confusing, especially if you were expecting a noticeable boost in attention or motivation. Let’s learn more about why this happens.

Why ADHD and sleep problems often go together

Long before medication enters the picture, ADHD and sleep often don’t get along. If you live with ADHD, you might already have trouble falling asleep, staying asleep, or waking up feeling rested.

This connection matters, because if you’re already not sleeping well, your body might not respond to medication in the way you’d expect. A stimulant might make you more aware of how tired you actually are. Or, if you finally feel calm after taking your medication, your brain might interpret that shift as a cue to wind down or even fall asleep.

For some, stimulants ease the mental restlessness that often comes with ADHD. That sudden stillness can feel unfamiliar. If your mind has always been busy and alert, that drop in stimulation might feel like a crash rather than a relief.

You might also feel sleepy if the medication starts to wear off too quickly. This is more likely with short-acting stimulants, but it can happen with long-acting ones too. That change in energy can leave you feeling flat, especially if it comes at a time when you need to be active or focused.

Why your body might react this way

Stimulants work by increasing the levels of certain brain chemicals, mostly dopamine and noradrenaline. These are involved in attention, motivation, and alertness.

In many people, this leads to better focus and energy. But the effects vary depending on your individual brain chemistry, your routine, and how well you’re sleeping.

You might notice tiredness if the medication timing doesn’t match your daily rhythm. Taking it too early, too late, or without food might shift how your body processes it. If you’re skipping meals or not drinking enough water, your energy might dip even further. Stimulants can suppress appetite, which means your body may not get enough fuel to function well throughout the day.

Another possibility is that a sleep disorder is going unnoticed. Conditions like obstructive sleep apnoea or periodic limb movement disorder can cause fragmented, poor-quality sleep. If these aren’t identified or treated, you might feel tired no matter what medication you’re taking.

What to do if you feel sleepy on ADHD medication

Feeling tired isn’t a reason to give up on treatment, but it is something to talk about with your doctor or prescribing clinician. There are ways to adjust your medication or your routine that can make a big difference.

Your doctor might recommend changing the dose, switching to a different formulation, or adjusting the time you take your medication. For example, some people benefit from taking their dose earlier in the day, or splitting their dose to reduce peaks and dips in energy.

It’s also worth checking for sleep issues. If you’re snoring, waking up a lot, or waking up tired, you might benefit from a sleep assessment. Treating an underlying sleep condition can often improve how you respond to ADHD medication.

In your daily life, building supportive habits around sleep, nutrition, and routine can help too. 

Try to keep a regular bedtime and wake-up time, even on weekends. Limit screen use in the hour before bed, and create a sleep space that feels calm and comfortable.

Make sure you’re eating enough during the day, especially in the morning and early afternoon. Physical activity, even in small amounts, can also help regulate your energy and sleep quality.

You could also try keeping a short journal to track when you take your medication, how you feel during the day, and how you’re sleeping at night. This can help you and your clinician spot patterns and make more informed decisions about your treatment.

When a different approach might help

If you’ve made some adjustments and you’re still feeling sleepy, it might be time to revisit your treatment plan.

Some people find they respond better to non-stimulant medication, especially if sleep issues are a major concern. These alternatives, like atomoxetine or guanfacine, may have different effects on energy and alertness.

For others, a combined approach works best. This could include a lower dose of medication, along with therapy focused on sleep, attention, or managing daily routines. Cognitive behavioural therapy for insomnia (CBT-I), for instance, has helped many people with ADHD improve their sleep over time.

Every person’s experience with ADHD is different. What works for someone else may not work for you, and that’s okay. The important thing is to stay open to adjustments and to give yourself time to find the right combination of support.