Short answer: mixing prescription ADHD stimulants (like lisdexamfetamine, methylphenidate, or dexamfetamine) with psychedelics can raise the chance of overstimulation, anxiety, and cardiovascular strain. Risk varies by substance and setting.
Highest concern is ayahuasca, because it contains MAO‑A inhibitors. Stimulants combined with MAOIs are widely warned against in official product information (see the Dutch SmPC for dexamfetamine). Many programs require a conservative washout and advise not to combine at all.
MDMA plus stimulants has human data showing higher heart rate, blood pressure, and side effects compared with either alone. Clinical MDMA‑therapy protocols typically require pausing stimulants before and for a period after a session. Outside trials, the safest approach is to avoid this pairing.
Ketamine already raises blood pressure for some people, and clinics often monitor vitals and may ask patients to skip a stimulant dose on treatment days. For psilocybin or LSD, evidence is limited; the main practical risk is extra stimulation and anxiety. A conservative harm‑reduction approach is not to mix and to discuss any pause plan with your prescriber.
If you are unsure, do not combine and prioritize safety.