Also known as: Amfexa (UK brand), Dexedrine (US), d-amphetamine (generic)
Dexamfetamine (dexamfetamine sulphate) is a short-acting ADHD stimulant prescribed in the UK as tablets taken two to three times a day. It is also the active compound that Elvanse (lisdexamfetamine) converts into in your body. Some people take dexamfetamine as their primary medication, while others use it as a booster alongside Elvanse or another long-acting formulation. ADHDose tracks each dose individually and models the combined levels when doses overlap.
Dexamfetamine is a direct-acting stimulant. Unlike Elvanse, which must be converted by your body before it takes effect, dexamfetamine enters your bloodstream in its active form after being absorbed in the stomach. This gives it a faster onset but a shorter duration.
A single dose typically takes effect within 20 to 30 minutes, peaks at around 1 to 2 hours, and clears within 3 to 5 hours. Because of this, most people take it two or three times a day, timing each dose to maintain coverage through the hours they need it most.
With multiple daily doses, the profile through the day depends entirely on when you take each one. ADHDose models this by tracking each dose individually and showing you the combined concentration at any point.
Dexamfetamine and Elvanse are closely related. Elvanse (lisdexamfetamine) is a prodrug: your body's enzymes convert it into dexamfetamine, which is the compound that actually produces the therapeutic effect. The difference is in the delivery. Elvanse provides a slow, sustained conversion over many hours from a single dose. Dexamfetamine tablets deliver the active compound directly, producing a faster but shorter effect.
Because they share the same active compound, dexamfetamine is sometimes prescribed as an afternoon booster for people on Elvanse whose coverage runs out before the end of the day. The combined profile is predictable because the body is working with the same substance in both cases.
Not everyone on dexamfetamine uses it as a booster. Some people take it as their primary ADHD medication, particularly if they prefer the flexibility of controlling the timing and size of each dose through the day rather than relying on a single long-acting dose.
The main trade-off is management. Multiple daily doses mean more decisions about timing, and a missed or late dose creates a gap in coverage. For some people, this flexibility is an advantage. For others, it's a source of difficulty, especially given that remembering to take medication at precise intervals is exactly the kind of task ADHD makes harder.
Dexamfetamine titration in the UK typically starts at a low dose, often 5mg once or twice daily, and increases gradually based on your response. The total daily dose is built up by adjusting how many tablets you take and at what times.
Because each dose is short-acting, your prescriber can observe the effect of adjustments more quickly than with long-acting medications. This can make early titration faster to navigate, though it requires more detailed tracking of when you took each dose and how you felt.
ADHDose tracks each dexamfetamine dose individually. When multiple doses are active at the same time, the app shows you the combined coverage so you can see your total levels rather than guessing from individual doses.
If you take dexamfetamine as a booster alongside Elvanse, ADHDose models both together so you can see the combined effect and how it affects your wind-down window.
See every dose, every overlap, and how it combines with your other medication. Free to download, no account needed.
Download free →This page is for informational purposes only. ADHDose is not a medical device and does not provide medical advice, diagnosis, or treatment. Always consult your prescribing doctor or specialist before making changes to your medication.