Comparative Acute Effects of R-MDMA and S-MDMA in Healthy Participants

Inclusion Criteria:

1. Age between 18 and 65 years
2. Good understanding of the German language
3. Understanding of procedures and risks associated with the study
4. Willing to adhere to the protocol and signing of the consent form
5. Willing to refrain from the consumption of illicit psychoactive substances during the study
6. Willing not to operate heavy machinery within 48 h after administration of a study substance (including driving a car)
7. Willing to use effective birth-control throughout study participation.
8. Body mass index 18 - 34.9 kg/m2

Exclusion Criteria:

1. Relevant chronic or acute medical condition
2. Current or previous major psychiatric disorder (e.g. bipolar disorder, schizophrenia), current depression or anxiety disorder
3. Psychotic disorder or bipolar disorder in first-degree relatives
4. Hypertension (SBP\>140/90 mmHg) or hypotension (SBP\<85 mmHg)
5. Illicit substance use (not including cannabis) more than 20 times or any time within the previous month.
6. Pregnancy or current breastfeeding
7. Participation in another clinical trial (currently or within the last 30 days)
8. Use of medications that may interfere with the effects of the study medication
9. Tobacco smoking (\>10 cigarettes/day).
10. Excessive consumption of alcoholic beverages (\>15 drinks/week)