How Dextroamphetamine XR Works in Your Brain

Dextroamphetamine XR works by increasing the levels of two key brain chemicals — dopamine and norepinephrine — that help you focus, pay attention, and control impulses.

If you've ever wondered what's actually happening in your brain when you take this medication, this article breaks it down in plain English.

What It Does in Your Body

Your brain communicates through chemical messengers called neurotransmitters. Two of the most important ones for focus and attention are dopamine and norepinephrine.

In people with ADHD, these neurotransmitters don't work as efficiently as they should. Think of it like a mail system where letters keep getting picked up before anyone reads them — the messages are sent, but they don't stick around long enough to do their job.

Dextroamphetamine XR fixes this in two ways:

1. It blocks the reuptake of dopamine and norepinephrine. Normally, after these chemicals deliver their message, they get recycled (pulled back into the sending nerve cell). Dextroamphetamine blocks this recycling process, so dopamine and norepinephrine stay active longer in the gap between nerve cells.
2. It increases the release of dopamine and norepinephrine. The medication also pushes more of these chemicals out of nerve cells and into the gap where they can do their work.

The result? More dopamine and norepinephrine are available in the parts of your brain responsible for attention, focus, and impulse control. This is why people with ADHD often describe feeling "clearer" or more organized when the medication is working.

To a lesser extent, dextroamphetamine also inhibits monoamine oxidase (MAO), an enzyme that breaks down dopamine and norepinephrine. This adds to the overall effect of keeping these brain chemicals active for longer.

How Long Does It Take to Work?

Dextroamphetamine XR is an extended-release formulation. Here's the typical timeline:

• Onset: You'll start feeling effects within 30 to 60 minutes after taking a dose.
• Peak effect: The medication reaches its full effect around 2 to 3 hours after dosing.
• Duration: Effects last approximately 8 to 10 hours.

The extended-release capsule (originally called Dexedrine Spansule) works by releasing some of the medication right away and the rest gradually throughout the day. The capsule contains tiny beads — some dissolve quickly and others dissolve slowly — which is what creates the extended effect.

This is why you should never crush or chew the beads. Doing so would release all the medication at once, defeating the purpose of the extended-release design and increasing the risk of side effects.

How Long Does It Last?

A single morning dose of dextroamphetamine XR typically provides 8 to 10 hours of symptom relief. For most people, that covers the school day or workday.

The duration can vary depending on:

• Your metabolism — Faster metabolizers may find the medication wears off sooner.
• Stomach acidity — Acidic foods and drinks (like orange juice or vitamin C supplements) can decrease absorption and shorten the effect. Alkaline foods may extend it.
• Your dose — Higher doses don't necessarily last longer, but they may feel more effective during peak hours.

What Makes It Different from Similar Medications?

There are several stimulant medications used for ADHD. Here's how dextroamphetamine XR compares:

Dextroamphetamine XR vs. Adderall XR

Adderall XR contains a mix of four amphetamine salts — both dextroamphetamine and levoamphetamine. Dextroamphetamine XR contains only dextroamphetamine. Some patients find pure dextroamphetamine has fewer peripheral side effects (like jitteriness) because the l-isomer contributes more to physical stimulation.

Dextroamphetamine XR vs. Vyvanse

Vyvanse (lisdexamfetamine) is actually a prodrug of dextroamphetamine — your body converts it into dextroamphetamine after you swallow it. Vyvanse was designed to have a smoother onset and lower abuse potential because it can't be snorted or injected effectively. It also lasts slightly longer (up to 12–14 hours).

Dextroamphetamine XR vs. Methylphenidate (Ritalin, Concerta)

Methylphenidate is a completely different stimulant class. While it also increases dopamine, it works primarily by blocking reuptake without significantly increasing release. Some patients respond better to amphetamines, others to methylphenidate — it often comes down to individual brain chemistry.

Dextroamphetamine XR vs. Immediate-Release Dextroamphetamine

The immediate-release form (Zenzedi, generic dextroamphetamine tablets) works faster but only lasts 4–6 hours. Many patients need to take it 2–3 times daily. The XR version is more convenient and provides steadier coverage.

Final Thoughts

Dextroamphetamine XR works by boosting dopamine and norepinephrine in your brain — the two chemicals most involved in focus and attention. Its extended-release design gives you steady coverage throughout the day from a single morning dose.

If you're taking dextroamphetamine XR or considering it, learn about potential side effects and drug interactions to watch for. And if you're having trouble finding it at your pharmacy, Medfinder can help you locate it nearby.