Adderall and dexamfetamine are the two most directly related medicines on this list — dexamfetamine is one of the two active amphetamine compounds that make up Adderall. Understanding the difference comes down to formulation, not the underlying chemistry.
What each one is
Adderall combines dextroamphetamine and levoamphetamine — chemically related forms of amphetamine — in a fixed ratio (commonly around 3:1), sold as a US-licensed branded product.
Dexamfetamine, prescribed in the UK under the brand Amfexa and available generically, contains dexamfetamine sulfate on its own — the same active compound as the dextroamphetamine portion of Adderall, without the second amphetamine isomer. In the UK, Amfexa's licence covers children and adolescents aged 6–17, initiated and supervised by a specialist in childhood or adolescent behavioural disorders, typically after methylphenidate hasn't been effective enough — it isn't a UK-licensed adult ADHD option in its own right.
Why the difference matters clinically
Adderall's combination of two related amphetamine isomers was originally designed to balance efficacy and duration in a single product. UK dexamfetamine, as a single-compound medicine, gives prescribers a more straightforward dosing profile, and is generally shorter-acting — meaning it's often taken more than once during the day rather than as a single dose. This can be an advantage for people who benefit from finer control over when the medication is active, and a drawback for people who prefer once-daily dosing (more commonly achieved in the UK with lisdexamfetamine/Elvanse instead).
Which is more similar to Adderall — dexamfetamine or Elvanse?
Chemically, dexamfetamine is arguably the closer match, since it's a direct component of Adderall rather than a prodrug that converts to one. Practically, Elvanse (lisdexamfetamine) is often the medicine UK clinicians and patients discuss as "the UK Adderall equivalent" because of its once-daily dosing, which is closer to how many people use Adderall XR in the US. Neither is a perfect substitute — see our Adderall vs Elvanse guide for that comparison.
Prescribing considerations
Dexamfetamine is a Schedule 2 controlled drug in the UK, prescribed only after formal ADHD diagnosis, following the same NICE-guided pathway as every other UK stimulant medication. Dose and timing are individualised, and — as with all stimulant ADHD medications — should never be adjusted without prescriber input.
Related Dexamfetamine & Adderall Reading
Read our full dexamfetamine medication page for more on how it's used in UK ADHD treatment, or see the complete ADHD medication guide for how it fits alongside the other options.
Source: EMC — Amfexa SmPC.