Yes. In a controlled crossover study with healthy volunteers, a supplemental MDMA dose extended the overall duration of subjective effects by roughly one hour, without increasing peak intensity.
Side effects were more frequent after MDMA than after placebo. The study did not clearly show whether the booster produced more side effects than a single dose.
These findings suggest a booster can make the experience last longer, but they do not show that a longer session leads to better clinical outcomes.
Details are reported in a double blind randomized study in Translational Psychiatry.
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